Introduce helper functions for working with the live DT tree, all of them related to dynamically adding/removing nodes and properties.
__of_free_property() frees a dynamically created property __of_free_tree() recursively frees a device node tree __of_copy_property() copies a property dynamically __of_create_empty_node() creates an empty node Bug fix about prop->len == 0 by Ionut Nicu <[email protected]> Signed-off-by: Pantelis Antoniou <[email protected]> --- drivers/of/Makefile | 2 +- drivers/of/util.c | 210 ++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of.h | 55 ++++++++++++++ 3 files changed, 266 insertions(+), 1 deletion(-) create mode 100644 drivers/of/util.c diff --git a/drivers/of/Makefile b/drivers/of/Makefile index ed9660a..26de2ed 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -1,4 +1,4 @@ -obj-y = base.o device.o platform.o +obj-y = base.o device.o platform.o util.o obj-$(CONFIG_OF_FLATTREE) += fdt.o obj-$(CONFIG_OF_PROMTREE) += pdt.o obj-$(CONFIG_OF_ADDRESS) += address.o diff --git a/drivers/of/util.c b/drivers/of/util.c new file mode 100644 index 0000000..df747af --- /dev/null +++ b/drivers/of/util.c @@ -0,0 +1,210 @@ +/* + * Utility functions for working with device tree(s) + * + * Copyright (C) 2012 Pantelis Antoniou <[email protected]> + * Copyright (C) 2012 Texas Instruments Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/err.h> + +/** + * __of_free_property - release the memory of an allocated property + * @prop: Property to release + * + * Release the memory of an allocated property only after checking + * that the property has been marked as OF_DYNAMIC. + * Only call on known allocated properties. + */ +void __of_free_property(struct property *prop) +{ + if (prop == NULL) + return; + + if (of_property_check_flag(prop, OF_DYNAMIC)) { + if (of_property_check_flag(prop, OF_ALLOCVALUE)) + kfree(prop->value); + if (of_property_check_flag(prop, OF_ALLOCNAME)) + kfree(prop->name); + kfree(prop); + } +} + +/** + * __of_free_tree - release the memory of a device tree node and + * of all it's children + properties. + * @node: Device Tree node to release + * + * Release the memory of a device tree node and of all it's children. + * Also release the properties and the dead properties. + * Only call on detached node trees, and you better be sure that + * no pointer exist for any properties. Only safe to do if you + * absolutely control the life cycle of the node. + * Also note that the node is not removed from the all_nodes list, + * neither from the parent's child list; this should be handled before + * calling this function. + */ +void __of_free_tree(struct device_node *node) +{ + struct property *prop; + struct device_node *noden; + + /* sanity check */ + if (!node) + return; + + /* free recursively any children */ + while ((noden = node->child) != NULL) { + node->child = noden->sibling; + __of_free_tree(noden); + } + + /* free every property already allocated */ + while ((prop = node->properties) != NULL) { + node->properties = prop->next; + __of_free_property(prop); + } + + /* free dead properties already allocated */ + while ((prop = node->deadprops) != NULL) { + node->deadprops = prop->next; + __of_free_property(prop); + } + + if (of_node_check_flag(node, OF_DYNAMIC)) { + if (of_node_check_flag(node, OF_ALLOCFULL)) + kfree(node->full_name); + if (of_node_check_flag(node, OF_ALLOCTYPE)) + kfree(node->type); + if (of_node_check_flag(node, OF_ALLOCNAME)) + kfree(node->name); + kfree(node); + } +} + +/** + * __of_copy_property - Copy a property dynamically. + * @prop: Property to copy + * @allocflags: Allocation flags (typically pass GFP_KERNEL) + * @propflags: Property flags + * + * Copy a property by dynamically allocating the memory of both the + * property stucture and the property name & contents. The property's + * flags have the OF_DYNAMIC bit set so that we can differentiate between + * dynamically allocated properties and not. + * Returns the newly allocated property or NULL on out of memory error. + */ +struct property *__of_copy_property(const struct property *prop, + gfp_t allocflags, unsigned long propflags) +{ + struct property *propn; + + propn = kzalloc(sizeof(*prop), allocflags); + if (propn == NULL) + return NULL; + + propn->_flags = propflags; + + if (of_property_check_flag(propn, OF_ALLOCNAME)) { + propn->name = kstrdup(prop->name, allocflags); + if (propn->name == NULL) + goto err_fail_name; + } else + propn->name = prop->name; + + if (prop->length > 0) { + if (of_property_check_flag(propn, OF_ALLOCVALUE)) { + propn->value = kmalloc(prop->length, allocflags); + if (propn->value == NULL) + goto err_fail_value; + memcpy(propn->value, prop->value, prop->length); + } else + propn->value = prop->value; + + propn->length = prop->length; + } + + /* mark the property as dynamic */ + of_property_set_flag(propn, OF_DYNAMIC); + + return propn; + +err_fail_value: + if (of_property_check_flag(propn, OF_ALLOCNAME)) + kfree(propn->name); +err_fail_name: + kfree(propn); + return NULL; +} + +/** + * __of_create_empty_node - Create an empty device node dynamically. + * @name: Name of the new device node + * @type: Type of the new device node + * @full_name: Full name of the new device node + * @phandle: Phandle of the new device node + * @allocflags: Allocation flags (typically pass GFP_KERNEL) + * @nodeflags: Node flags + * + * Create an empty device tree node, suitable for further modification. + * The node data are dynamically allocated and all the node flags + * have the OF_DYNAMIC & OF_DETACHED bits set. + * Returns the newly allocated node or NULL on out of memory error. + */ +struct device_node *__of_create_empty_node( + const char *name, const char *type, const char *full_name, + phandle phandle, gfp_t allocflags, unsigned long nodeflags) +{ + struct device_node *node; + + node = kzalloc(sizeof(*node), allocflags); + if (node == NULL) + return NULL; + + node->_flags = nodeflags; + + if (of_node_check_flag(node, OF_ALLOCNAME)) { + node->name = kstrdup(name, allocflags); + if (node->name == NULL) + goto err_return; + } else + node->name = name; + + if (of_node_check_flag(node, OF_ALLOCTYPE)) { + node->type = kstrdup(type, allocflags); + if (node->type == NULL) + goto err_return; + } else + node->type = type; + + if (of_node_check_flag(node, OF_ALLOCFULL)) { + node->full_name = kstrdup(full_name, allocflags); + if (node->full_name == NULL) + goto err_return; + } else + node->full_name = full_name; + + node->phandle = phandle; + of_node_set_flag(node, OF_DYNAMIC); + of_node_set_flag(node, OF_DETACHED); + + of_node_init(node); + + return node; + +err_return: + __of_free_tree(node); + return NULL; +} diff --git a/include/linux/of.h b/include/linux/of.h index bef3d5b..9a55889 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -197,6 +197,15 @@ static inline unsigned long of_read_ulong(const __be32 *cell, int size) /* flag descriptions */ #define OF_DYNAMIC 1 /* node and properties were allocated via kmalloc */ #define OF_DETACHED 2 /* node has been detached from the device tree */ +#define OF_ALLOCNAME 3 /* name was kmalloc-ed */ +#define OF_ALLOCTYPE 4 /* type was kmalloc-ed */ +#define OF_ALLOCFULL 5 /* full_name was kmalloc-ed */ +#define OF_ALLOCVALUE 6 /* value was kmalloc-ed */ + +#define OF_NODE_ALLOCALL \ + ((1 << OF_ALLOCNAME) | (1 << OF_ALLOCTYPE) | (1 << OF_ALLOCFULL)) +#define OF_PROP_ALLOCALL \ + ((1 << OF_ALLOCNAME) | (1 << OF_ALLOCVALUE)) #define OF_IS_DYNAMIC(x) test_bit(OF_DYNAMIC, &x->_flags) #define OF_MARK_DYNAMIC(x) set_bit(OF_DYNAMIC, &x->_flags) @@ -680,4 +689,50 @@ static inline int of_get_available_child_count(const struct device_node *np) return num; } +/** + * General utilities for working with live trees. + * + * All functions with two leading underscores operate + * without taking node references, so you either have to + * own the devtree lock or work on detached trees only. + */ + +#ifdef CONFIG_OF + +/* iterator for internal use; not references, neither affects devtree lock */ +#define __for_each_child_of_node(dn, chld) \ + for (chld = (dn)->child; chld != NULL; chld = chld->sibling) + +void __of_free_property(struct property *prop); +void __of_free_tree(struct device_node *node); +struct property *__of_copy_property(const struct property *prop, + gfp_t allocflags, unsigned long propflags); +struct device_node *__of_create_empty_node( const char *name, + const char *type, const char *full_name, + phandle phandle, gfp_t allocflags, unsigned long nodeflags); + +#else /* !CONFIG_OF */ + +#define __for_each_child_of_node(dn, chld) \ + while (0) + +static inline void __of_free_property(struct property *prop) { } + +static inline void __of_free_tree(struct device_node *node) { } + +static inline struct property *__of_copy_property(const struct property *prop, + gfp_t allocflags, unsigned long propflags) +{ + return NULL; +} + +static inline struct device_node *__of_create_empty_node( const char *name, + const char *type, const char *full_name, + phandle phandle, gfp_t allocflags, unsigned long nodeflags) +{ + return NULL; +} + +#endif /* !CONFIG_OF */ + #endif /* _LINUX_OF_H */ -- 1.7.12 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
