1328970deSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 251798222SChristoph Hellwig /* 351798222SChristoph Hellwig * vim: noexpandtab ts=8 sts=0 sw=8: 451798222SChristoph Hellwig * 551798222SChristoph Hellwig * configfs_example_macros.c - This file is a demonstration module 651798222SChristoph Hellwig * containing a number of configfs subsystems. It uses the helper 751798222SChristoph Hellwig * macros defined by configfs.h 851798222SChristoph Hellwig * 951798222SChristoph Hellwig * Based on sysfs: 1051798222SChristoph Hellwig * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel 1151798222SChristoph Hellwig * 1251798222SChristoph Hellwig * configfs Copyright (C) 2005 Oracle. All rights reserved. 1351798222SChristoph Hellwig */ 1451798222SChristoph Hellwig 1551798222SChristoph Hellwig #include <linux/init.h> 1651798222SChristoph Hellwig #include <linux/module.h> 1751798222SChristoph Hellwig #include <linux/slab.h> 1851798222SChristoph Hellwig #include <linux/configfs.h> 1951798222SChristoph Hellwig 2051798222SChristoph Hellwig /* 2151798222SChristoph Hellwig * 01-childless 2251798222SChristoph Hellwig * 2351798222SChristoph Hellwig * This first example is a childless subsystem. It cannot create 2451798222SChristoph Hellwig * any config_items. It just has attributes. 2551798222SChristoph Hellwig * 2651798222SChristoph Hellwig * Note that we are enclosing the configfs_subsystem inside a container. 2751798222SChristoph Hellwig * This is not necessary if a subsystem has no attributes directly 2851798222SChristoph Hellwig * on the subsystem. See the next example, 02-simple-children, for 2951798222SChristoph Hellwig * such a subsystem. 3051798222SChristoph Hellwig */ 3151798222SChristoph Hellwig 3251798222SChristoph Hellwig struct childless { 3351798222SChristoph Hellwig struct configfs_subsystem subsys; 3451798222SChristoph Hellwig int showme; 3551798222SChristoph Hellwig int storeme; 3651798222SChristoph Hellwig }; 3751798222SChristoph Hellwig 3851798222SChristoph Hellwig static inline struct childless *to_childless(struct config_item *item) 3951798222SChristoph Hellwig { 40e0ee1fdbSBartosz Golaszewski return container_of(to_configfs_subsystem(to_config_group(item)), 41e0ee1fdbSBartosz Golaszewski struct childless, subsys); 4251798222SChristoph Hellwig } 4351798222SChristoph Hellwig 4451798222SChristoph Hellwig static ssize_t childless_showme_show(struct config_item *item, char *page) 4551798222SChristoph Hellwig { 4651798222SChristoph Hellwig struct childless *childless = to_childless(item); 4751798222SChristoph Hellwig ssize_t pos; 4851798222SChristoph Hellwig 4951798222SChristoph Hellwig pos = sprintf(page, "%d\n", childless->showme); 5051798222SChristoph Hellwig childless->showme++; 5151798222SChristoph Hellwig 5251798222SChristoph Hellwig return pos; 5351798222SChristoph Hellwig } 5451798222SChristoph Hellwig 5551798222SChristoph Hellwig static ssize_t childless_storeme_show(struct config_item *item, char *page) 5651798222SChristoph Hellwig { 5751798222SChristoph Hellwig return sprintf(page, "%d\n", to_childless(item)->storeme); 5851798222SChristoph Hellwig } 5951798222SChristoph Hellwig 6051798222SChristoph Hellwig static ssize_t childless_storeme_store(struct config_item *item, 6151798222SChristoph Hellwig const char *page, size_t count) 6251798222SChristoph Hellwig { 6351798222SChristoph Hellwig struct childless *childless = to_childless(item); 6451798222SChristoph Hellwig unsigned long tmp; 6551798222SChristoph Hellwig char *p = (char *) page; 6651798222SChristoph Hellwig 6751798222SChristoph Hellwig tmp = simple_strtoul(p, &p, 10); 6851798222SChristoph Hellwig if (!p || (*p && (*p != '\n'))) 6951798222SChristoph Hellwig return -EINVAL; 7051798222SChristoph Hellwig 7151798222SChristoph Hellwig if (tmp > INT_MAX) 7251798222SChristoph Hellwig return -ERANGE; 7351798222SChristoph Hellwig 7451798222SChristoph Hellwig childless->storeme = tmp; 7551798222SChristoph Hellwig 7651798222SChristoph Hellwig return count; 7751798222SChristoph Hellwig } 7851798222SChristoph Hellwig 7951798222SChristoph Hellwig static ssize_t childless_description_show(struct config_item *item, char *page) 8051798222SChristoph Hellwig { 8151798222SChristoph Hellwig return sprintf(page, 8251798222SChristoph Hellwig "[01-childless]\n" 8351798222SChristoph Hellwig "\n" 8451798222SChristoph Hellwig "The childless subsystem is the simplest possible subsystem in\n" 8551798222SChristoph Hellwig "configfs. It does not support the creation of child config_items.\n" 8651798222SChristoph Hellwig "It only has a few attributes. In fact, it isn't much different\n" 8751798222SChristoph Hellwig "than a directory in /proc.\n"); 8851798222SChristoph Hellwig } 8951798222SChristoph Hellwig 9051798222SChristoph Hellwig CONFIGFS_ATTR_RO(childless_, showme); 9151798222SChristoph Hellwig CONFIGFS_ATTR(childless_, storeme); 9251798222SChristoph Hellwig CONFIGFS_ATTR_RO(childless_, description); 9351798222SChristoph Hellwig 9451798222SChristoph Hellwig static struct configfs_attribute *childless_attrs[] = { 9551798222SChristoph Hellwig &childless_attr_showme, 9651798222SChristoph Hellwig &childless_attr_storeme, 9751798222SChristoph Hellwig &childless_attr_description, 9851798222SChristoph Hellwig NULL, 9951798222SChristoph Hellwig }; 10051798222SChristoph Hellwig 10184c43674SBhumika Goyal static const struct config_item_type childless_type = { 10251798222SChristoph Hellwig .ct_attrs = childless_attrs, 10351798222SChristoph Hellwig .ct_owner = THIS_MODULE, 10451798222SChristoph Hellwig }; 10551798222SChristoph Hellwig 10651798222SChristoph Hellwig static struct childless childless_subsys = { 10751798222SChristoph Hellwig .subsys = { 10851798222SChristoph Hellwig .su_group = { 10951798222SChristoph Hellwig .cg_item = { 11051798222SChristoph Hellwig .ci_namebuf = "01-childless", 11151798222SChristoph Hellwig .ci_type = &childless_type, 11251798222SChristoph Hellwig }, 11351798222SChristoph Hellwig }, 11451798222SChristoph Hellwig }, 11551798222SChristoph Hellwig }; 11651798222SChristoph Hellwig 11751798222SChristoph Hellwig /* ----------------------------------------------------------------- */ 11851798222SChristoph Hellwig 11951798222SChristoph Hellwig /* 12051798222SChristoph Hellwig * 02-simple-children 12151798222SChristoph Hellwig * 12251798222SChristoph Hellwig * This example merely has a simple one-attribute child. Note that 12351798222SChristoph Hellwig * there is no extra attribute structure, as the child's attribute is 12451798222SChristoph Hellwig * known from the get-go. Also, there is no container for the 12551798222SChristoph Hellwig * subsystem, as it has no attributes of its own. 12651798222SChristoph Hellwig */ 12751798222SChristoph Hellwig 12851798222SChristoph Hellwig struct simple_child { 12951798222SChristoph Hellwig struct config_item item; 13051798222SChristoph Hellwig int storeme; 13151798222SChristoph Hellwig }; 13251798222SChristoph Hellwig 13351798222SChristoph Hellwig static inline struct simple_child *to_simple_child(struct config_item *item) 13451798222SChristoph Hellwig { 135e0ee1fdbSBartosz Golaszewski return container_of(item, struct simple_child, item); 13651798222SChristoph Hellwig } 13751798222SChristoph Hellwig 13851798222SChristoph Hellwig static ssize_t simple_child_storeme_show(struct config_item *item, char *page) 13951798222SChristoph Hellwig { 14051798222SChristoph Hellwig return sprintf(page, "%d\n", to_simple_child(item)->storeme); 14151798222SChristoph Hellwig } 14251798222SChristoph Hellwig 14351798222SChristoph Hellwig static ssize_t simple_child_storeme_store(struct config_item *item, 14451798222SChristoph Hellwig const char *page, size_t count) 14551798222SChristoph Hellwig { 14651798222SChristoph Hellwig struct simple_child *simple_child = to_simple_child(item); 14751798222SChristoph Hellwig unsigned long tmp; 14851798222SChristoph Hellwig char *p = (char *) page; 14951798222SChristoph Hellwig 15051798222SChristoph Hellwig tmp = simple_strtoul(p, &p, 10); 15151798222SChristoph Hellwig if (!p || (*p && (*p != '\n'))) 15251798222SChristoph Hellwig return -EINVAL; 15351798222SChristoph Hellwig 15451798222SChristoph Hellwig if (tmp > INT_MAX) 15551798222SChristoph Hellwig return -ERANGE; 15651798222SChristoph Hellwig 15751798222SChristoph Hellwig simple_child->storeme = tmp; 15851798222SChristoph Hellwig 15951798222SChristoph Hellwig return count; 16051798222SChristoph Hellwig } 16151798222SChristoph Hellwig 16251798222SChristoph Hellwig CONFIGFS_ATTR(simple_child_, storeme); 16351798222SChristoph Hellwig 16451798222SChristoph Hellwig static struct configfs_attribute *simple_child_attrs[] = { 16551798222SChristoph Hellwig &simple_child_attr_storeme, 16651798222SChristoph Hellwig NULL, 16751798222SChristoph Hellwig }; 16851798222SChristoph Hellwig 16951798222SChristoph Hellwig static void simple_child_release(struct config_item *item) 17051798222SChristoph Hellwig { 17151798222SChristoph Hellwig kfree(to_simple_child(item)); 17251798222SChristoph Hellwig } 17351798222SChristoph Hellwig 17451798222SChristoph Hellwig static struct configfs_item_operations simple_child_item_ops = { 17551798222SChristoph Hellwig .release = simple_child_release, 17651798222SChristoph Hellwig }; 17751798222SChristoph Hellwig 17884c43674SBhumika Goyal static const struct config_item_type simple_child_type = { 17951798222SChristoph Hellwig .ct_item_ops = &simple_child_item_ops, 18051798222SChristoph Hellwig .ct_attrs = simple_child_attrs, 18151798222SChristoph Hellwig .ct_owner = THIS_MODULE, 18251798222SChristoph Hellwig }; 18351798222SChristoph Hellwig 18451798222SChristoph Hellwig struct simple_children { 18551798222SChristoph Hellwig struct config_group group; 18651798222SChristoph Hellwig }; 18751798222SChristoph Hellwig 18851798222SChristoph Hellwig static inline struct simple_children *to_simple_children(struct config_item *item) 18951798222SChristoph Hellwig { 190e0ee1fdbSBartosz Golaszewski return container_of(to_config_group(item), 191e0ee1fdbSBartosz Golaszewski struct simple_children, group); 19251798222SChristoph Hellwig } 19351798222SChristoph Hellwig 19451798222SChristoph Hellwig static struct config_item *simple_children_make_item(struct config_group *group, 19551798222SChristoph Hellwig const char *name) 19651798222SChristoph Hellwig { 19751798222SChristoph Hellwig struct simple_child *simple_child; 19851798222SChristoph Hellwig 19951798222SChristoph Hellwig simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL); 20051798222SChristoph Hellwig if (!simple_child) 20151798222SChristoph Hellwig return ERR_PTR(-ENOMEM); 20251798222SChristoph Hellwig 20351798222SChristoph Hellwig config_item_init_type_name(&simple_child->item, name, 20451798222SChristoph Hellwig &simple_child_type); 20551798222SChristoph Hellwig 20651798222SChristoph Hellwig simple_child->storeme = 0; 20751798222SChristoph Hellwig 20851798222SChristoph Hellwig return &simple_child->item; 20951798222SChristoph Hellwig } 21051798222SChristoph Hellwig 21151798222SChristoph Hellwig static ssize_t simple_children_description_show(struct config_item *item, 21251798222SChristoph Hellwig char *page) 21351798222SChristoph Hellwig { 21451798222SChristoph Hellwig return sprintf(page, 21551798222SChristoph Hellwig "[02-simple-children]\n" 21651798222SChristoph Hellwig "\n" 21751798222SChristoph Hellwig "This subsystem allows the creation of child config_items. These\n" 21851798222SChristoph Hellwig "items have only one attribute that is readable and writeable.\n"); 21951798222SChristoph Hellwig } 22051798222SChristoph Hellwig 22151798222SChristoph Hellwig CONFIGFS_ATTR_RO(simple_children_, description); 22251798222SChristoph Hellwig 22351798222SChristoph Hellwig static struct configfs_attribute *simple_children_attrs[] = { 22451798222SChristoph Hellwig &simple_children_attr_description, 22551798222SChristoph Hellwig NULL, 22651798222SChristoph Hellwig }; 22751798222SChristoph Hellwig 22851798222SChristoph Hellwig static void simple_children_release(struct config_item *item) 22951798222SChristoph Hellwig { 23051798222SChristoph Hellwig kfree(to_simple_children(item)); 23151798222SChristoph Hellwig } 23251798222SChristoph Hellwig 23351798222SChristoph Hellwig static struct configfs_item_operations simple_children_item_ops = { 23451798222SChristoph Hellwig .release = simple_children_release, 23551798222SChristoph Hellwig }; 23651798222SChristoph Hellwig 23751798222SChristoph Hellwig /* 23851798222SChristoph Hellwig * Note that, since no extra work is required on ->drop_item(), 23951798222SChristoph Hellwig * no ->drop_item() is provided. 24051798222SChristoph Hellwig */ 24151798222SChristoph Hellwig static struct configfs_group_operations simple_children_group_ops = { 24251798222SChristoph Hellwig .make_item = simple_children_make_item, 24351798222SChristoph Hellwig }; 24451798222SChristoph Hellwig 24584c43674SBhumika Goyal static const struct config_item_type simple_children_type = { 24651798222SChristoph Hellwig .ct_item_ops = &simple_children_item_ops, 24751798222SChristoph Hellwig .ct_group_ops = &simple_children_group_ops, 24851798222SChristoph Hellwig .ct_attrs = simple_children_attrs, 24951798222SChristoph Hellwig .ct_owner = THIS_MODULE, 25051798222SChristoph Hellwig }; 25151798222SChristoph Hellwig 25251798222SChristoph Hellwig static struct configfs_subsystem simple_children_subsys = { 25351798222SChristoph Hellwig .su_group = { 25451798222SChristoph Hellwig .cg_item = { 25551798222SChristoph Hellwig .ci_namebuf = "02-simple-children", 25651798222SChristoph Hellwig .ci_type = &simple_children_type, 25751798222SChristoph Hellwig }, 25851798222SChristoph Hellwig }, 25951798222SChristoph Hellwig }; 26051798222SChristoph Hellwig 26151798222SChristoph Hellwig /* ----------------------------------------------------------------- */ 26251798222SChristoph Hellwig 26351798222SChristoph Hellwig /* 26451798222SChristoph Hellwig * 03-group-children 26551798222SChristoph Hellwig * 26651798222SChristoph Hellwig * This example reuses the simple_children group from above. However, 26751798222SChristoph Hellwig * the simple_children group is not the subsystem itself, it is a 26851798222SChristoph Hellwig * child of the subsystem. Creation of a group in the subsystem creates 26951798222SChristoph Hellwig * a new simple_children group. That group can then have simple_child 27051798222SChristoph Hellwig * children of its own. 27151798222SChristoph Hellwig */ 27251798222SChristoph Hellwig 27351798222SChristoph Hellwig static struct config_group *group_children_make_group( 27451798222SChristoph Hellwig struct config_group *group, const char *name) 27551798222SChristoph Hellwig { 27651798222SChristoph Hellwig struct simple_children *simple_children; 27751798222SChristoph Hellwig 27851798222SChristoph Hellwig simple_children = kzalloc(sizeof(struct simple_children), 27951798222SChristoph Hellwig GFP_KERNEL); 28051798222SChristoph Hellwig if (!simple_children) 28151798222SChristoph Hellwig return ERR_PTR(-ENOMEM); 28251798222SChristoph Hellwig 28351798222SChristoph Hellwig config_group_init_type_name(&simple_children->group, name, 28451798222SChristoph Hellwig &simple_children_type); 28551798222SChristoph Hellwig 28651798222SChristoph Hellwig return &simple_children->group; 28751798222SChristoph Hellwig } 28851798222SChristoph Hellwig 28951798222SChristoph Hellwig static ssize_t group_children_description_show(struct config_item *item, 29051798222SChristoph Hellwig char *page) 29151798222SChristoph Hellwig { 29251798222SChristoph Hellwig return sprintf(page, 29351798222SChristoph Hellwig "[03-group-children]\n" 29451798222SChristoph Hellwig "\n" 29551798222SChristoph Hellwig "This subsystem allows the creation of child config_groups. These\n" 29651798222SChristoph Hellwig "groups are like the subsystem simple-children.\n"); 29751798222SChristoph Hellwig } 29851798222SChristoph Hellwig 29951798222SChristoph Hellwig CONFIGFS_ATTR_RO(group_children_, description); 30051798222SChristoph Hellwig 30151798222SChristoph Hellwig static struct configfs_attribute *group_children_attrs[] = { 30251798222SChristoph Hellwig &group_children_attr_description, 30351798222SChristoph Hellwig NULL, 30451798222SChristoph Hellwig }; 30551798222SChristoph Hellwig 30651798222SChristoph Hellwig /* 30751798222SChristoph Hellwig * Note that, since no extra work is required on ->drop_item(), 30851798222SChristoph Hellwig * no ->drop_item() is provided. 30951798222SChristoph Hellwig */ 31051798222SChristoph Hellwig static struct configfs_group_operations group_children_group_ops = { 31151798222SChristoph Hellwig .make_group = group_children_make_group, 31251798222SChristoph Hellwig }; 31351798222SChristoph Hellwig 31484c43674SBhumika Goyal static const struct config_item_type group_children_type = { 31551798222SChristoph Hellwig .ct_group_ops = &group_children_group_ops, 31651798222SChristoph Hellwig .ct_attrs = group_children_attrs, 31751798222SChristoph Hellwig .ct_owner = THIS_MODULE, 31851798222SChristoph Hellwig }; 31951798222SChristoph Hellwig 32051798222SChristoph Hellwig static struct configfs_subsystem group_children_subsys = { 32151798222SChristoph Hellwig .su_group = { 32251798222SChristoph Hellwig .cg_item = { 32351798222SChristoph Hellwig .ci_namebuf = "03-group-children", 32451798222SChristoph Hellwig .ci_type = &group_children_type, 32551798222SChristoph Hellwig }, 32651798222SChristoph Hellwig }, 32751798222SChristoph Hellwig }; 32851798222SChristoph Hellwig 32951798222SChristoph Hellwig /* ----------------------------------------------------------------- */ 33051798222SChristoph Hellwig 33151798222SChristoph Hellwig /* 33251798222SChristoph Hellwig * We're now done with our subsystem definitions. 33351798222SChristoph Hellwig * For convenience in this module, here's a list of them all. It 33451798222SChristoph Hellwig * allows the init function to easily register them. Most modules 33551798222SChristoph Hellwig * will only have one subsystem, and will only call register_subsystem 33651798222SChristoph Hellwig * on it directly. 33751798222SChristoph Hellwig */ 33851798222SChristoph Hellwig static struct configfs_subsystem *example_subsys[] = { 33951798222SChristoph Hellwig &childless_subsys.subsys, 34051798222SChristoph Hellwig &simple_children_subsys, 34151798222SChristoph Hellwig &group_children_subsys, 34251798222SChristoph Hellwig NULL, 34351798222SChristoph Hellwig }; 34451798222SChristoph Hellwig 34551798222SChristoph Hellwig static int __init configfs_example_init(void) 34651798222SChristoph Hellwig { 34751798222SChristoph Hellwig int ret; 34851798222SChristoph Hellwig int i; 34951798222SChristoph Hellwig struct configfs_subsystem *subsys; 35051798222SChristoph Hellwig 35151798222SChristoph Hellwig for (i = 0; example_subsys[i]; i++) { 35251798222SChristoph Hellwig subsys = example_subsys[i]; 35351798222SChristoph Hellwig 35451798222SChristoph Hellwig config_group_init(&subsys->su_group); 35551798222SChristoph Hellwig mutex_init(&subsys->su_mutex); 35651798222SChristoph Hellwig ret = configfs_register_subsystem(subsys); 35751798222SChristoph Hellwig if (ret) { 35851798222SChristoph Hellwig printk(KERN_ERR "Error %d while registering subsystem %s\n", 35951798222SChristoph Hellwig ret, 36051798222SChristoph Hellwig subsys->su_group.cg_item.ci_namebuf); 36151798222SChristoph Hellwig goto out_unregister; 36251798222SChristoph Hellwig } 36351798222SChristoph Hellwig } 36451798222SChristoph Hellwig 36551798222SChristoph Hellwig return 0; 36651798222SChristoph Hellwig 36751798222SChristoph Hellwig out_unregister: 36851798222SChristoph Hellwig for (i--; i >= 0; i--) 36951798222SChristoph Hellwig configfs_unregister_subsystem(example_subsys[i]); 37051798222SChristoph Hellwig 37151798222SChristoph Hellwig return ret; 37251798222SChristoph Hellwig } 37351798222SChristoph Hellwig 37451798222SChristoph Hellwig static void __exit configfs_example_exit(void) 37551798222SChristoph Hellwig { 37651798222SChristoph Hellwig int i; 37751798222SChristoph Hellwig 37851798222SChristoph Hellwig for (i = 0; example_subsys[i]; i++) 37951798222SChristoph Hellwig configfs_unregister_subsystem(example_subsys[i]); 38051798222SChristoph Hellwig } 38151798222SChristoph Hellwig 38251798222SChristoph Hellwig module_init(configfs_example_init); 38351798222SChristoph Hellwig module_exit(configfs_example_exit); 38451798222SChristoph Hellwig MODULE_LICENSE("GPL"); 385