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