// SPDX-License-Identifier: GPL-2.0 /* * Software nodes for the firmware node framework. * * Copyright (C) 2018, Intel Corporation * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com> */ #include <linux/device.h> #include <linux/kernel.h> #include <linux/property.h> #include <linux/slab.h> struct swnode { int id; struct kobject kobj; struct fwnode_handle fwnode; const struct software_node *node; /* hierarchy */ struct ida child_ids; struct list_head entry; struct list_head children; struct swnode *parent; unsigned int allocated:1; }; static DEFINE_IDA(swnode_root_ids); static struct kset *swnode_kset; #define kobj_to_swnode(_kobj_) container_of(_kobj_, struct swnode, kobj) static const struct fwnode_operations software_node_ops; bool is_software_node(const struct fwnode_handle *fwnode) { return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &software_node_ops; } EXPORT_SYMBOL_GPL(is_software_node); #define to_swnode(__fwnode) \ ({ \ typeof(__fwnode) __to_swnode_fwnode = __fwnode; \ \ is_software_node(__to_swnode_fwnode) ? \ container_of(__to_swnode_fwnode, \ struct swnode, fwnode) : NULL; \ }) static struct swnode * software_node_to_swnode(const struct software_node *node) { struct swnode *swnode = NULL; struct kobject *k; if (!node) return NULL; spin_lock(&swnode_kset->list_lock); list_for_each_entry(k, &swnode_kset->list, entry) { swnode = kobj_to_swnode(k); if (swnode->node == node) break; swnode = NULL; } spin_unlock(&swnode_kset->list_lock); return swnode; } const struct software_node *to_software_node(const struct fwnode_handle *fwnode) { const struct swnode *swnode = to_swnode(fwnode); return swnode ? swnode->node : NULL; } EXPORT_SYMBOL_GPL(to_software_node); struct fwnode_handle *software_node_fwnode(const struct software_node *node) { struct swnode *swnode = software_node_to_swnode(node); return swnode ? &swnode->fwnode : NULL; } EXPORT_SYMBOL_GPL(software_node_fwnode); /* -------------------------------------------------------------------------- */ /* property_entry processing */ static const struct property_entry * property_entry_get(const struct property_entry *prop, const char *name) { if (!prop) return NULL; for (; prop->name; prop++) if (!strcmp(name, prop->name)) return prop; return NULL; } static const void *property_get_pointer(const struct property_entry *prop) { if (!prop->length) return NULL; return prop->is_inline ? &prop->value : prop->pointer; } static const void *property_entry_find(const struct property_entry *props, const char *propname, size_t length) { const struct property_entry *prop; const void *pointer; prop = property_entry_get(props, propname); if (!prop) return ERR_PTR(-EINVAL); pointer = property_get_pointer(prop); if (!pointer) return ERR_PTR(-ENODATA); if (length > prop->length) return ERR_PTR(-EOVERFLOW); return pointer; } static int property_entry_count_elems_of_size(const struct property_entry *props, const char *propname, size_t length) { const struct property_entry *prop; prop = property_entry_get(props, propname); if (!prop) return -EINVAL; return prop->length / length; } static int property_entry_read_int_array(const struct property_entry *props, const char *name, unsigned int elem_size, void *val, size_t nval) { const void *pointer; size_t length; if (!val) return property_entry_count_elems_of_size(props, name, elem_size); if (!is_power_of_2(elem_size) || elem_size > sizeof(u64)) return -ENXIO; length = nval * elem_size; pointer = property_entry_find(props, name, length); if (IS_ERR(pointer)) return PTR_ERR(pointer); memcpy(val, pointer, length); return 0; } static int property_entry_read_string_array(const struct property_entry *props, const char *propname, const char **strings, size_t nval) { const void *pointer; size_t length; int array_len; /* Find out the array length. */ array_len = property_entry_count_elems_of_size(props, propname, sizeof(const char *)); if (array_len < 0) return array_len; /* Return how many there are if strings is NULL. */ if (!strings) return array_len; array_len = min_t(size_t, nval, array_len); length = array_len * sizeof(*strings); pointer = property_entry_find(props, propname, length); if (IS_ERR(pointer)) return PTR_ERR(pointer); memcpy(strings, pointer, length); return array_len; } static void property_entry_free_data(const struct property_entry *p) { const char * const *src_str; size_t i, nval; if (p->type == DEV_PROP_STRING) { src_str = property_get_pointer(p); nval = p->length / sizeof(*src_str); for (i = 0; i < nval; i++) kfree(src_str[i]); } if (!p->is_inline) kfree(p->pointer); kfree(p->name); } static bool property_copy_string_array(const char **dst_ptr, const char * const *src_ptr, size_t nval) { int i; for (i = 0; i < nval; i++) { dst_ptr[i] = kstrdup(src_ptr[i], GFP_KERNEL); if (!dst_ptr[i] && src_ptr[i]) { while (--i >= 0) kfree(dst_ptr[i]); return false; } } return true; } static int property_entry_copy_data(struct property_entry *dst, const struct property_entry *src) { const void *pointer = property_get_pointer(src); void *dst_ptr; size_t nval; /* * Properties with no data should not be marked as stored * out of line. */ if (!src->is_inline && !src->length) return -ENODATA; /* * Reference properties are never stored inline as * they are too big. */ if (src->type == DEV_PROP_REF && src->is_inline) return -EINVAL; if (src->length <= sizeof(dst->value)) { dst_ptr = &dst->value; dst->is_inline = true; } else { dst_ptr = kmalloc(src->length, GFP_KERNEL); if (!dst_ptr) return -ENOMEM; dst->pointer = dst_ptr; } if (src->type == DEV_PROP_STRING) { nval = src->length / sizeof(const char *); if (!property_copy_string_array(dst_ptr, pointer, nval)) { if (!dst->is_inline) kfree(dst->pointer); return -ENOMEM; } } else { memcpy(dst_ptr, pointer, src->length); } dst->length = src->length; dst->type = src->type; dst->name = kstrdup(src->name, GFP_KERNEL); if (!dst->name) { property_entry_free_data(dst); return -ENOMEM; } return 0; } /** * property_entries_dup - duplicate array of properties * @properties: array of properties to copy * * This function creates a deep copy of the given NULL-terminated array * of property entries. */ struct property_entry * property_entries_dup(const struct property_entry *properties) { struct property_entry *p; int i, n = 0; int ret; if (!properties) return NULL; while (properties[n].name) n++; p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL); if (!p) return ERR_PTR(-ENOMEM); for (i = 0; i < n; i++) { ret = property_entry_copy_data(&p[i], &properties[i]); if (ret) { while (--i >= 0) property_entry_free_data(&p[i]); kfree(p); return ERR_PTR(ret); } } return p; } EXPORT_SYMBOL_GPL(property_entries_dup); /** * property_entries_free - free previously allocated array of properties * @properties: array of properties to destroy * * This function frees given NULL-terminated array of property entries, * along with their data. */ void property_entries_free(const struct property_entry *properties) { const struct property_entry *p; if (!properties) return; for (p = properties; p->name; p++) property_entry_free_data(p); kfree(properties); } EXPORT_SYMBOL_GPL(property_entries_free); /* -------------------------------------------------------------------------- */ /* fwnode operations */ static struct fwnode_handle *software_node_get(struct fwnode_handle *fwnode) { struct swnode *swnode = to_swnode(fwnode); kobject_get(&swnode->kobj); return &swnode->fwnode; } static void software_node_put(struct fwnode_handle *fwnode) { struct swnode *swnode = to_swnode(fwnode); kobject_put(&swnode->kobj); } static bool software_node_property_present(const struct fwnode_handle *fwnode, const char *propname) { struct swnode *swnode = to_swnode(fwnode); return !!property_entry_get(swnode->node->properties, propname); } static int software_node_read_int_array(const struct fwnode_handle *fwnode, const char *propname, unsigned int elem_size, void *val, size_t nval) { struct swnode *swnode = to_swnode(fwnode); return property_entry_read_int_array(swnode->node->properties, propname, elem_size, val, nval); } static int software_node_read_string_array(const struct fwnode_handle *fwnode, const char *propname, const char **val, size_t nval) { struct swnode *swnode = to_swnode(fwnode); return property_entry_read_string_array(swnode->node->properties, propname, val, nval); } static const char * software_node_get_name(const struct fwnode_handle *fwnode) { const struct swnode *swnode = to_swnode(fwnode); if (!swnode) return "(null)"; return kobject_name(&swnode->kobj); } static const char * software_node_get_name_prefix(const struct fwnode_handle *fwnode) { struct fwnode_handle *parent; const char *prefix; parent = fwnode_get_parent(fwnode); if (!parent) return ""; /* Figure out the prefix from the parents. */ while (is_software_node(parent)) parent = fwnode_get_next_parent(parent); prefix = fwnode_get_name_prefix(parent); fwnode_handle_put(parent); /* Guess something if prefix was NULL. */ return prefix ?: "/"; } static struct fwnode_handle * software_node_get_parent(const struct fwnode_handle *fwnode) { struct swnode *swnode = to_swnode(fwnode); if (!swnode || !swnode->parent) return NULL; return fwnode_handle_get(&swnode->parent->fwnode); } static struct fwnode_handle * software_node_get_next_child(const struct fwnode_handle *fwnode, struct fwnode_handle *child) { struct swnode *p = to_swnode(fwnode); struct swnode *c = to_swnode(child); if (!p || list_empty(&p->children) || (c && list_is_last(&c->entry, &p->children))) return NULL; if (c) c = list_next_entry(c, entry); else c = list_first_entry(&p->children, struct swnode, entry); return &c->fwnode; } static struct fwnode_handle * software_node_get_named_child_node(const struct fwnode_handle *fwnode, const char *childname) { struct swnode *swnode = to_swnode(fwnode); struct swnode *child; if (!swnode || list_empty(&swnode->children)) return NULL; list_for_each_entry(child, &swnode->children, entry) { if (!strcmp(childname, kobject_name(&child->kobj))) { kobject_get(&child->kobj); return &child->fwnode; } } return NULL; } static int software_node_get_reference_args(const struct fwnode_handle *fwnode, const char *propname, const char *nargs_prop, unsigned int nargs, unsigned int index, struct fwnode_reference_args *args) { struct swnode *swnode = to_swnode(fwnode); const struct software_node_ref_args *ref_array; const struct software_node_ref_args *ref; const struct property_entry *prop; struct fwnode_handle *refnode; u32 nargs_prop_val; int error; int i; if (!swnode) return -ENOENT; prop = property_entry_get(swnode->node->properties, propname); if (!prop) return -ENOENT; if (prop->type != DEV_PROP_REF) return -EINVAL; /* * We expect that references are never stored inline, even * single ones, as they are too big. */ if (prop->is_inline) return -EINVAL; if (index * sizeof(*ref) >= prop->length) return -ENOENT; ref_array = prop->pointer; ref = &ref_array[index]; refnode = software_node_fwnode(ref->node); if (!refnode) return -ENOENT; if (nargs_prop) { error = property_entry_read_int_array(swnode->node->properties, nargs_prop, sizeof(u32), &nargs_prop_val, 1); if (error) return error; nargs = nargs_prop_val; } if (nargs > NR_FWNODE_REFERENCE_ARGS) return -EINVAL; args->fwnode = software_node_get(refnode); args->nargs = nargs; for (i = 0; i < nargs; i++) args->args[i] = ref->args[i]; return 0; } static const struct fwnode_operations software_node_ops = { .get = software_node_get, .put = software_node_put, .property_present = software_node_property_present, .property_read_int_array = software_node_read_int_array, .property_read_string_array = software_node_read_string_array, .get_name = software_node_get_name, .get_name_prefix = software_node_get_name_prefix, .get_parent = software_node_get_parent, .get_next_child_node = software_node_get_next_child, .get_named_child_node = software_node_get_named_child_node, .get_reference_args = software_node_get_reference_args }; /* -------------------------------------------------------------------------- */ /** * software_node_find_by_name - Find software node by name * @parent: Parent of the software node * @name: Name of the software node * * The function will find a node that is child of @parent and that is named * @name. If no node is found, the function returns NULL. * * NOTE: you will need to drop the reference with fwnode_handle_put() after use. */ const struct software_node * software_node_find_by_name(const struct software_node *parent, const char *name) { struct swnode *swnode = NULL; struct kobject *k; if (!name) return NULL; spin_lock(&swnode_kset->list_lock); list_for_each_entry(k, &swnode_kset->list, entry) { swnode = kobj_to_swnode(k); if (parent == swnode->node->parent && swnode->node->name && !strcmp(name, swnode->node->name)) { kobject_get(&swnode->kobj); break; } swnode = NULL; } spin_unlock(&swnode_kset->list_lock); return swnode ? swnode->node : NULL; } EXPORT_SYMBOL_GPL(software_node_find_by_name); static int software_node_register_properties(struct software_node *node, const struct property_entry *properties) { struct property_entry *props; props = property_entries_dup(properties); if (IS_ERR(props)) return PTR_ERR(props); node->properties = props; return 0; } static void software_node_release(struct kobject *kobj) { struct swnode *swnode = kobj_to_swnode(kobj); if (swnode->allocated) { property_entries_free(swnode->node->properties); kfree(swnode->node); } ida_destroy(&swnode->child_ids); kfree(swnode); } static struct kobj_type software_node_type = { .release = software_node_release, .sysfs_ops = &kobj_sysfs_ops, }; static struct fwnode_handle * swnode_register(const struct software_node *node, struct swnode *parent, unsigned int allocated) { struct swnode *swnode; int ret; swnode = kzalloc(sizeof(*swnode), GFP_KERNEL); if (!swnode) { ret = -ENOMEM; goto out_err; } ret = ida_simple_get(parent ? &parent->child_ids : &swnode_root_ids, 0, 0, GFP_KERNEL); if (ret < 0) { kfree(swnode); goto out_err; } swnode->id = ret; swnode->node = node; swnode->parent = parent; swnode->allocated = allocated; swnode->kobj.kset = swnode_kset; swnode->fwnode.ops = &software_node_ops; ida_init(&swnode->child_ids); INIT_LIST_HEAD(&swnode->entry); INIT_LIST_HEAD(&swnode->children); if (node->name) ret = kobject_init_and_add(&swnode->kobj, &software_node_type, parent ? &parent->kobj : NULL, "%s", node->name); else ret = kobject_init_and_add(&swnode->kobj, &software_node_type, parent ? &parent->kobj : NULL, "node%d", swnode->id); if (ret) { kobject_put(&swnode->kobj); return ERR_PTR(ret); } if (parent) list_add_tail(&swnode->entry, &parent->children); kobject_uevent(&swnode->kobj, KOBJ_ADD); return &swnode->fwnode; out_err: if (allocated) property_entries_free(node->properties); return ERR_PTR(ret); } /** * software_node_register_nodes - Register an array of software nodes * @nodes: Zero terminated array of software nodes to be registered * * Register multiple software nodes at once. */ int software_node_register_nodes(const struct software_node *nodes) { int ret; int i; for (i = 0; nodes[i].name; i++) { ret = software_node_register(&nodes[i]); if (ret) { software_node_unregister_nodes(nodes); return ret; } } return 0; } EXPORT_SYMBOL_GPL(software_node_register_nodes); /** * software_node_unregister_nodes - Unregister an array of software nodes * @nodes: Zero terminated array of software nodes to be unregistered * * Unregister multiple software nodes at once. */ void software_node_unregister_nodes(const struct software_node *nodes) { struct swnode *swnode; int i; for (i = 0; nodes[i].name; i++) { swnode = software_node_to_swnode(&nodes[i]); if (swnode) fwnode_remove_software_node(&swnode->fwnode); } } EXPORT_SYMBOL_GPL(software_node_unregister_nodes); /** * software_node_register - Register static software node * @node: The software node to be registered */ int software_node_register(const struct software_node *node) { struct swnode *parent = software_node_to_swnode(node->parent); if (software_node_to_swnode(node)) return -EEXIST; return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0)); } EXPORT_SYMBOL_GPL(software_node_register); struct fwnode_handle * fwnode_create_software_node(const struct property_entry *properties, const struct fwnode_handle *parent) { struct software_node *node; struct swnode *p = NULL; int ret; if (parent) { if (IS_ERR(parent)) return ERR_CAST(parent); if (!is_software_node(parent)) return ERR_PTR(-EINVAL); p = to_swnode(parent); } node = kzalloc(sizeof(*node), GFP_KERNEL); if (!node) return ERR_PTR(-ENOMEM); ret = software_node_register_properties(node, properties); if (ret) { kfree(node); return ERR_PTR(ret); } node->parent = p ? p->node : NULL; return swnode_register(node, p, 1); } EXPORT_SYMBOL_GPL(fwnode_create_software_node); void fwnode_remove_software_node(struct fwnode_handle *fwnode) { struct swnode *swnode = to_swnode(fwnode); if (!swnode) return; if (swnode->parent) { ida_simple_remove(&swnode->parent->child_ids, swnode->id); list_del(&swnode->entry); } else { ida_simple_remove(&swnode_root_ids, swnode->id); } kobject_put(&swnode->kobj); } EXPORT_SYMBOL_GPL(fwnode_remove_software_node); int software_node_notify(struct device *dev, unsigned long action) { struct fwnode_handle *fwnode = dev_fwnode(dev); struct swnode *swnode; int ret; if (!fwnode) return 0; if (!is_software_node(fwnode)) fwnode = fwnode->secondary; if (!is_software_node(fwnode)) return 0; swnode = to_swnode(fwnode); switch (action) { case KOBJ_ADD: ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node"); if (ret) break; ret = sysfs_create_link(&swnode->kobj, &dev->kobj, dev_name(dev)); if (ret) { sysfs_remove_link(&dev->kobj, "software_node"); break; } kobject_get(&swnode->kobj); break; case KOBJ_REMOVE: sysfs_remove_link(&swnode->kobj, dev_name(dev)); sysfs_remove_link(&dev->kobj, "software_node"); kobject_put(&swnode->kobj); break; default: break; } return 0; } static int __init software_node_init(void) { swnode_kset = kset_create_and_add("software_nodes", NULL, kernel_kobj); if (!swnode_kset) return -ENOMEM; return 0; } postcore_initcall(software_node_init); static void __exit software_node_exit(void) { ida_destroy(&swnode_root_ids); kset_unregister(swnode_kset); } __exitcall(software_node_exit);