Hello Pantelis!
On 22/06/14 11:40, ext Pantelis Antoniou wrote:
> Introduce helper functions for working with the live DT tree,
> all of them related to dynamically adding/removing nodes and
> properties.
>
> __of_copy_property() copies a property dynamically
> __of_create_empty_node() creates an empty node
>
> Bug fix about prop->len == 0 by Ionut Nicu <ioan.nicu.ext@xxxxxxx>
Are you sure about this? (see below...)
> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
> ---
> drivers/of/Makefile | 2 +-
> drivers/of/util.c | 141 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/of.h | 42 ++++++++++++++++
> 3 files changed, 184 insertions(+), 1 deletion(-)
> create mode 100644 drivers/of/util.c
>
> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> index 099b1fb..734d3e2 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_EARLY_FLATTREE) += fdt_address.o
> obj-$(CONFIG_OF_PROMTREE) += pdt.o
> diff --git a/drivers/of/util.c b/drivers/of/util.c
> new file mode 100644
> index 0000000..f4211f8
> --- /dev/null
> +++ b/drivers/of/util.c
> @@ -0,0 +1,141 @@
> +/*
> + * Utility functions for working with device tree(s)
> + *
> + * Copyright (C) 2012 Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx>
> + * 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_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) {
^^^^^^^^^^^^^^^^^^^^^
Seems, that length==0 case will still produce value==NULL results,
which will brake some checks in the kernel... Or am I missing something in
the new version?
> + 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_free_node;
> + } else
> + node->name = name;
> +
> + if (of_node_check_flag(node, OF_ALLOCTYPE)) {
> + node->type = kstrdup(type, allocflags);
> + if (node->type == NULL)
> + goto err_free_name;
> + } 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_free_type;
> + } 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_free_type:
> + if (of_node_check_flag(node, OF_ALLOCTYPE))
> + kfree(node->type);
> +err_free_name:
> + if (of_node_check_flag(node, OF_ALLOCNAME))
> + kfree(node->name);
> +err_free_node:
> + kfree(node);
> + return NULL;
> +}
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 5e4e1b3..d381eb5 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -211,6 +211,15 @@ static inline unsigned long of_read_ulong(const __be32 *cell, int size)
> #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_POPULATED 3 /* device already created for the node */
> +#define OF_ALLOCNAME 4 /* name was kmalloc-ed */
> +#define OF_ALLOCTYPE 5 /* type was kmalloc-ed */
> +#define OF_ALLOCFULL 6 /* full_name was kmalloc-ed */
> +#define OF_ALLOCVALUE 7 /* 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)
> @@ -824,4 +833,37 @@ typedef void (*of_init_fn_1)(struct device_node *);
> #define OF_DECLARE_2(table, name, compat, fn) \
> _OF_DECLARE(table, name, compat, fn, of_init_fn_2)
>
> +/**
> + * 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
> +
> +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 */
> +
> +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 */
>
--
Best regards,
Alexander Sverdlin.
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