diff options
Diffstat (limited to 'drivers/of/base.c')
| -rw-r--r-- | drivers/of/base.c | 174 |
1 files changed, 166 insertions, 8 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 48594f334151..3b70a468c8ab 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -23,6 +23,7 @@ #include <linux/of.h> #include <linux/spinlock.h> #include <linux/slab.h> +#include <linux/string.h> #include <linux/proc_fs.h> #include "of_private.h" @@ -35,6 +36,12 @@ struct device_node *of_chosen; struct device_node *of_aliases; static struct device_node *of_stdout; +static struct kset *of_kset; + +/* + * Used to protect the of_aliases; but also overloaded to hold off addition of + * nodes to sysfs + */ DEFINE_MUTEX(of_aliases_mutex); /* use when traversing tree through the allnext, child, sibling, @@ -92,14 +99,14 @@ int __weak of_node_to_nid(struct device_node *np) struct device_node *of_node_get(struct device_node *node) { if (node) - kref_get(&node->kref); + kobject_get(&node->kobj); return node; } EXPORT_SYMBOL(of_node_get); -static inline struct device_node *kref_to_device_node(struct kref *kref) +static inline struct device_node *kobj_to_device_node(struct kobject *kobj) { - return container_of(kref, struct device_node, kref); + return container_of(kobj, struct device_node, kobj); } /** @@ -109,16 +116,15 @@ static inline struct device_node *kref_to_device_node(struct kref *kref) * In of_node_put() this function is passed to kref_put() * as the destructor. */ -static void of_node_release(struct kref *kref) +static void of_node_release(struct kobject *kobj) { - struct device_node *node = kref_to_device_node(kref); + struct device_node *node = kobj_to_device_node(kobj); struct property *prop = node->properties; /* We should never be releasing nodes that haven't been detached. */ if (!of_node_check_flag(node, OF_DETACHED)) { pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name); dump_stack(); - kref_init(&node->kref); return; } @@ -151,11 +157,140 @@ static void of_node_release(struct kref *kref) void of_node_put(struct device_node *node) { if (node) - kref_put(&node->kref, of_node_release); + kobject_put(&node->kobj); } EXPORT_SYMBOL(of_node_put); +#else +static void of_node_release(struct kobject *kobj) +{ + /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */ +} #endif /* CONFIG_OF_DYNAMIC */ +struct kobj_type of_node_ktype = { + .release = of_node_release, +}; + +static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, char *buf, + loff_t offset, size_t count) +{ + struct property *pp = container_of(bin_attr, struct property, attr); + return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length); +} + +static const char *safe_name(struct kobject *kobj, const char *orig_name) +{ + const char *name = orig_name; + struct kernfs_node *kn; + int i = 0; + + /* don't be a hero. After 16 tries give up */ + while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) { + sysfs_put(kn); + if (name != orig_name) + kfree(name); + name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i); + } + + if (name != orig_name) + pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n", + kobject_name(kobj), name); + return name; +} + +static int __of_add_property_sysfs(struct device_node *np, struct property *pp) +{ + int rc; + + /* Important: Don't leak passwords */ + bool secure = strncmp(pp->name, "security-", 9) == 0; + + sysfs_bin_attr_init(&pp->attr); + pp->attr.attr.name = safe_name(&np->kobj, pp->name); + pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO; + pp->attr.size = secure ? 0 : pp->length; + pp->attr.read = of_node_property_read; + + rc = sysfs_create_bin_file(&np->kobj, &pp->attr); + WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name); + return rc; +} + +static int __of_node_add(struct device_node *np) +{ + const char *name; + struct property *pp; + int rc; + + np->kobj.kset = of_kset; + if (!np->parent) { + /* Nodes without parents are new top level trees */ + rc = kobject_add(&np->kobj, NULL, safe_name(&of_kset->kobj, "base")); + } else { + name = safe_name(&np->parent->kobj, kbasename(np->full_name)); + if (!name || !name[0]) + return -EINVAL; + + rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name); + } + if (rc) + return rc; + + for_each_property_of_node(np, pp) + __of_add_property_sysfs(np, pp); + + return 0; +} + +int of_node_add(struct device_node *np) +{ + int rc = 0; + kobject_init(&np->kobj, &of_node_ktype); + mutex_lock(&of_aliases_mutex); + if (of_kset) + rc = __of_node_add(np); + mutex_unlock(&of_aliases_mutex); + return rc; +} + +#if defined(CONFIG_OF_DYNAMIC) +static void of_node_remove(struct device_node *np) +{ + struct property *pp; + + for_each_property_of_node(np, pp) + sysfs_remove_bin_file(&np->kobj, &pp->attr); + + kobject_del(&np->kobj); +} +#endif + +static int __init of_init(void) +{ + struct device_node *np; + + /* Create the kset, and register existing nodes */ + mutex_lock(&of_aliases_mutex); + of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj); + if (!of_kset) { + mutex_unlock(&of_aliases_mutex); + return -ENOMEM; + } + for_each_of_allnodes(np) + __of_node_add(np); + mutex_unlock(&of_aliases_mutex); + +#if !defined(CONFIG_PROC_DEVICETREE) + /* Symlink to the new tree when PROC_DEVICETREE is disabled */ + if (of_allnodes) + proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base"); +#endif /* CONFIG_PROC_DEVICETREE */ + + return 0; +} +core_initcall(of_init); + static struct property *__of_find_property(const struct device_node *np, const char *name, int *lenp) { @@ -1546,6 +1681,14 @@ int of_add_property(struct device_node *np, struct property *prop) raw_spin_lock_irqsave(&devtree_lock, flags); rc = __of_add_property(np, prop); raw_spin_unlock_irqrestore(&devtree_lock, flags); + if (rc) + return rc; + + /* at early boot, bail hear and defer setup to of_init() */ + if (!of_kset) + return 0; + + __of_add_property_sysfs(np, prop); #ifdef CONFIG_PROC_DEVICETREE /* try to add to proc as well if it was initialized */ @@ -1593,6 +1736,12 @@ int of_remove_property(struct device_node *np, struct property *prop) if (!found) return -ENODEV; + /* at early boot, bail hear and defer setup to of_init() */ + if (!of_kset) + return 0; + + sysfs_remove_bin_file(&np->kobj, &prop->attr); + #ifdef CONFIG_PROC_DEVICETREE /* try to remove the proc node as well */ if (np->pde) @@ -1643,13 +1792,20 @@ int of_update_property(struct device_node *np, struct property *newprop) next = &(*next)->next; } raw_spin_unlock_irqrestore(&devtree_lock, flags); + if (rc) + return rc; + + /* Update the sysfs attribute */ + if (oldprop) + sysfs_remove_bin_file(&np->kobj, &oldprop->attr); + __of_add_property_sysfs(np, newprop); if (!found) return -ENODEV; #ifdef CONFIG_PROC_DEVICETREE /* try to add to proc as well if it was initialized */ - if (!rc && np->pde) + if (np->pde) proc_device_tree_update_prop(np->pde, newprop, oldprop); #endif /* CONFIG_PROC_DEVICETREE */ @@ -1723,6 +1879,7 @@ int of_attach_node(struct device_node *np) of_node_clear_flag(np, OF_DETACHED); raw_spin_unlock_irqrestore(&devtree_lock, flags); + of_node_add(np); of_add_proc_dt_entry(np); return 0; } @@ -1795,6 +1952,7 @@ int of_detach_node(struct device_node *np) raw_spin_unlock_irqrestore(&devtree_lock, flags); of_remove_proc_dt_entry(np); + of_node_remove(np); return rc; } #endif /* defined(CONFIG_OF_DYNAMIC) */ |