483 строки
10 KiB
C
483 строки
10 KiB
C
/*
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* drivers/s390/cio/ccwgroup.c
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* bus driver for ccwgroup
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* $Revision: 1.29 $
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*
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* Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
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* IBM Corporation
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* Author(s): Arnd Bergmann (arndb@de.ibm.com)
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* Cornelia Huck (cohuck@de.ibm.com)
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*/
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/list.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/ctype.h>
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#include <linux/dcache.h>
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#include <asm/semaphore.h>
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#include <asm/ccwdev.h>
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#include <asm/ccwgroup.h>
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/* In Linux 2.4, we had a channel device layer called "chandev"
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* that did all sorts of obscure stuff for networking devices.
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* This is another driver that serves as a replacement for just
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* one of its functions, namely the translation of single subchannels
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* to devices that use multiple subchannels.
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*/
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/* a device matches a driver if all its slave devices match the same
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* entry of the driver */
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static int
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ccwgroup_bus_match (struct device * dev, struct device_driver * drv)
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{
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struct ccwgroup_device *gdev;
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struct ccwgroup_driver *gdrv;
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gdev = container_of(dev, struct ccwgroup_device, dev);
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gdrv = container_of(drv, struct ccwgroup_driver, driver);
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if (gdev->creator_id == gdrv->driver_id)
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return 1;
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return 0;
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}
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static int
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ccwgroup_hotplug (struct device *dev, char **envp, int num_envp, char *buffer,
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int buffer_size)
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{
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/* TODO */
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return 0;
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}
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static struct bus_type ccwgroup_bus_type = {
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.name = "ccwgroup",
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.match = ccwgroup_bus_match,
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.hotplug = ccwgroup_hotplug,
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};
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static inline void
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__ccwgroup_remove_symlinks(struct ccwgroup_device *gdev)
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{
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int i;
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char str[8];
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for (i = 0; i < gdev->count; i++) {
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sprintf(str, "cdev%d", i);
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sysfs_remove_link(&gdev->dev.kobj, str);
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sysfs_remove_link(&gdev->cdev[i]->dev.kobj, "group_device");
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}
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}
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/*
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* Provide an 'ungroup' attribute so the user can remove group devices no
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* longer needed or accidentially created. Saves memory :)
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*/
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static ssize_t
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ccwgroup_ungroup_store(struct device *dev, const char *buf, size_t count)
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{
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struct ccwgroup_device *gdev;
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gdev = to_ccwgroupdev(dev);
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if (gdev->state != CCWGROUP_OFFLINE)
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return -EINVAL;
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__ccwgroup_remove_symlinks(gdev);
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device_unregister(dev);
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return count;
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}
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static DEVICE_ATTR(ungroup, 0200, NULL, ccwgroup_ungroup_store);
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static void
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ccwgroup_release (struct device *dev)
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{
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struct ccwgroup_device *gdev;
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int i;
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gdev = to_ccwgroupdev(dev);
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for (i = 0; i < gdev->count; i++) {
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gdev->cdev[i]->dev.driver_data = NULL;
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put_device(&gdev->cdev[i]->dev);
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}
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kfree(gdev);
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}
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static inline int
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__ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
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{
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char str[8];
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int i, rc;
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for (i = 0; i < gdev->count; i++) {
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rc = sysfs_create_link(&gdev->cdev[i]->dev.kobj, &gdev->dev.kobj,
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"group_device");
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if (rc) {
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for (--i; i >= 0; i--)
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sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
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"group_device");
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return rc;
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}
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}
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for (i = 0; i < gdev->count; i++) {
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sprintf(str, "cdev%d", i);
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rc = sysfs_create_link(&gdev->dev.kobj, &gdev->cdev[i]->dev.kobj,
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str);
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if (rc) {
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for (--i; i >= 0; i--) {
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sprintf(str, "cdev%d", i);
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sysfs_remove_link(&gdev->dev.kobj, str);
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}
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for (i = 0; i < gdev->count; i++)
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sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
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"group_device");
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return rc;
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}
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}
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return 0;
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}
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/*
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* try to add a new ccwgroup device for one driver
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* argc and argv[] are a list of bus_id's of devices
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* belonging to the driver.
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*/
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int
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ccwgroup_create(struct device *root,
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unsigned int creator_id,
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struct ccw_driver *cdrv,
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int argc, char *argv[])
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{
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struct ccwgroup_device *gdev;
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int i;
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int rc;
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int del_drvdata;
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if (argc > 256) /* disallow dumb users */
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return -EINVAL;
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gdev = kmalloc(sizeof(*gdev) + argc*sizeof(gdev->cdev[0]), GFP_KERNEL);
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if (!gdev)
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return -ENOMEM;
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memset(gdev, 0, sizeof(*gdev) + argc*sizeof(gdev->cdev[0]));
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atomic_set(&gdev->onoff, 0);
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del_drvdata = 0;
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for (i = 0; i < argc; i++) {
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gdev->cdev[i] = get_ccwdev_by_busid(cdrv, argv[i]);
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/* all devices have to be of the same type in
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* order to be grouped */
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if (!gdev->cdev[i]
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|| gdev->cdev[i]->id.driver_info !=
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gdev->cdev[0]->id.driver_info) {
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rc = -EINVAL;
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goto free_dev;
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}
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/* Don't allow a device to belong to more than one group. */
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if (gdev->cdev[i]->dev.driver_data) {
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rc = -EINVAL;
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goto free_dev;
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}
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}
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for (i = 0; i < argc; i++)
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gdev->cdev[i]->dev.driver_data = gdev;
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del_drvdata = 1;
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gdev->creator_id = creator_id;
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gdev->count = argc;
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gdev->dev = (struct device ) {
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.bus = &ccwgroup_bus_type,
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.parent = root,
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.release = ccwgroup_release,
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};
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snprintf (gdev->dev.bus_id, BUS_ID_SIZE, "%s",
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gdev->cdev[0]->dev.bus_id);
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rc = device_register(&gdev->dev);
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if (rc)
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goto free_dev;
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get_device(&gdev->dev);
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rc = device_create_file(&gdev->dev, &dev_attr_ungroup);
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if (rc) {
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device_unregister(&gdev->dev);
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goto error;
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}
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rc = __ccwgroup_create_symlinks(gdev);
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if (!rc) {
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put_device(&gdev->dev);
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return 0;
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}
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device_remove_file(&gdev->dev, &dev_attr_ungroup);
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device_unregister(&gdev->dev);
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error:
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for (i = 0; i < argc; i++)
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if (gdev->cdev[i]) {
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put_device(&gdev->cdev[i]->dev);
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gdev->cdev[i]->dev.driver_data = NULL;
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}
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put_device(&gdev->dev);
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return rc;
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free_dev:
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for (i = 0; i < argc; i++)
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if (gdev->cdev[i]) {
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put_device(&gdev->cdev[i]->dev);
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if (del_drvdata)
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gdev->cdev[i]->dev.driver_data = NULL;
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}
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kfree(gdev);
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return rc;
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}
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static int __init
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init_ccwgroup (void)
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{
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return bus_register (&ccwgroup_bus_type);
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}
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static void __exit
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cleanup_ccwgroup (void)
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{
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bus_unregister (&ccwgroup_bus_type);
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}
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module_init(init_ccwgroup);
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module_exit(cleanup_ccwgroup);
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/************************** driver stuff ******************************/
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static int
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ccwgroup_set_online(struct ccwgroup_device *gdev)
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{
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struct ccwgroup_driver *gdrv;
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int ret;
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if (atomic_compare_and_swap(0, 1, &gdev->onoff))
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return -EAGAIN;
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if (gdev->state == CCWGROUP_ONLINE) {
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ret = 0;
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goto out;
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}
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if (!gdev->dev.driver) {
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ret = -EINVAL;
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goto out;
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}
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gdrv = to_ccwgroupdrv (gdev->dev.driver);
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if ((ret = gdrv->set_online(gdev)))
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goto out;
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gdev->state = CCWGROUP_ONLINE;
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out:
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atomic_set(&gdev->onoff, 0);
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return ret;
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}
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static int
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ccwgroup_set_offline(struct ccwgroup_device *gdev)
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{
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struct ccwgroup_driver *gdrv;
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int ret;
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if (atomic_compare_and_swap(0, 1, &gdev->onoff))
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return -EAGAIN;
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if (gdev->state == CCWGROUP_OFFLINE) {
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ret = 0;
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goto out;
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}
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if (!gdev->dev.driver) {
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ret = -EINVAL;
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goto out;
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}
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gdrv = to_ccwgroupdrv (gdev->dev.driver);
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if ((ret = gdrv->set_offline(gdev)))
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goto out;
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gdev->state = CCWGROUP_OFFLINE;
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out:
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atomic_set(&gdev->onoff, 0);
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return ret;
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}
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static ssize_t
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ccwgroup_online_store (struct device *dev, const char *buf, size_t count)
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{
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struct ccwgroup_device *gdev;
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struct ccwgroup_driver *gdrv;
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unsigned int value;
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int ret;
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gdev = to_ccwgroupdev(dev);
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if (!dev->driver)
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return count;
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gdrv = to_ccwgroupdrv (gdev->dev.driver);
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if (!try_module_get(gdrv->owner))
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return -EINVAL;
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value = simple_strtoul(buf, 0, 0);
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ret = count;
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if (value == 1)
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ccwgroup_set_online(gdev);
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else if (value == 0)
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ccwgroup_set_offline(gdev);
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else
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ret = -EINVAL;
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module_put(gdrv->owner);
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return ret;
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}
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static ssize_t
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ccwgroup_online_show (struct device *dev, char *buf)
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{
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int online;
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online = (to_ccwgroupdev(dev)->state == CCWGROUP_ONLINE);
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return sprintf(buf, online ? "1\n" : "0\n");
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}
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static DEVICE_ATTR(online, 0644, ccwgroup_online_show, ccwgroup_online_store);
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static int
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ccwgroup_probe (struct device *dev)
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{
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struct ccwgroup_device *gdev;
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struct ccwgroup_driver *gdrv;
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int ret;
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gdev = to_ccwgroupdev(dev);
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gdrv = to_ccwgroupdrv(dev->driver);
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if ((ret = device_create_file(dev, &dev_attr_online)))
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return ret;
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pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
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ret = gdrv->probe ? gdrv->probe(gdev) : -ENODEV;
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if (ret)
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device_remove_file(dev, &dev_attr_online);
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return ret;
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}
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static int
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ccwgroup_remove (struct device *dev)
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{
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struct ccwgroup_device *gdev;
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struct ccwgroup_driver *gdrv;
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gdev = to_ccwgroupdev(dev);
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gdrv = to_ccwgroupdrv(dev->driver);
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pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
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device_remove_file(dev, &dev_attr_online);
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if (gdrv && gdrv->remove)
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gdrv->remove(gdev);
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return 0;
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}
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int
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ccwgroup_driver_register (struct ccwgroup_driver *cdriver)
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{
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/* register our new driver with the core */
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cdriver->driver = (struct device_driver) {
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.bus = &ccwgroup_bus_type,
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.name = cdriver->name,
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.probe = ccwgroup_probe,
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.remove = ccwgroup_remove,
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};
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return driver_register(&cdriver->driver);
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}
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static inline struct device *
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__get_next_ccwgroup_device(struct device_driver *drv)
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{
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struct device *dev, *d;
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down_read(&drv->bus->subsys.rwsem);
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dev = NULL;
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list_for_each_entry(d, &drv->devices, driver_list) {
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dev = get_device(d);
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if (dev)
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break;
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}
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up_read(&drv->bus->subsys.rwsem);
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return dev;
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}
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void
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ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver)
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{
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struct device *dev;
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/* We don't want ccwgroup devices to live longer than their driver. */
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get_driver(&cdriver->driver);
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while ((dev = __get_next_ccwgroup_device(&cdriver->driver))) {
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__ccwgroup_remove_symlinks(to_ccwgroupdev(dev));
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device_unregister(dev);
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put_device(dev);
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};
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put_driver(&cdriver->driver);
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driver_unregister(&cdriver->driver);
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}
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int
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ccwgroup_probe_ccwdev(struct ccw_device *cdev)
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{
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return 0;
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}
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static inline struct ccwgroup_device *
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__ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev)
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{
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struct ccwgroup_device *gdev;
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if (cdev->dev.driver_data) {
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gdev = (struct ccwgroup_device *)cdev->dev.driver_data;
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if (get_device(&gdev->dev)) {
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if (!list_empty(&gdev->dev.node))
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return gdev;
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put_device(&gdev->dev);
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}
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return NULL;
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}
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return NULL;
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}
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void
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ccwgroup_remove_ccwdev(struct ccw_device *cdev)
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{
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struct ccwgroup_device *gdev;
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/* Ignore offlining errors, device is gone anyway. */
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ccw_device_set_offline(cdev);
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/* If one of its devices is gone, the whole group is done for. */
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gdev = __ccwgroup_get_gdev_by_cdev(cdev);
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if (gdev) {
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__ccwgroup_remove_symlinks(gdev);
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device_unregister(&gdev->dev);
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put_device(&gdev->dev);
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}
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}
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MODULE_LICENSE("GPL");
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EXPORT_SYMBOL(ccwgroup_driver_register);
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EXPORT_SYMBOL(ccwgroup_driver_unregister);
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EXPORT_SYMBOL(ccwgroup_create);
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EXPORT_SYMBOL(ccwgroup_probe_ccwdev);
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EXPORT_SYMBOL(ccwgroup_remove_ccwdev);
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