Commit 69843396 authored by Pantelis Antoniou's avatar Pantelis Antoniou Committed by Grant Likely

OF: Utility helper functions for dynamic nodes

Introduce helper functions for working with the live DT tree,
all of them related to dynamically adding/removing nodes and
properties.

__of_prop_dup() copies a property dynamically
__of_node_alloc() creates an empty node

Bug fix about prop->len == 0 by Ionut Nicu <ioan.nicu.ext@nsn.com>
Signed-off-by: default avatarPantelis Antoniou <pantelis.antoniou@konsulko.com>
[glikely: Added unittest for of_copy_property and dropped fine-grained allocations]
[glikely: removed name, type and phandle arguments from __of_node_alloc]
Signed-off-by: default avatarGrant Likely <grant.likely@linaro.org>
parent 6afc0dc3
......@@ -214,3 +214,80 @@ void of_node_release(struct kobject *kobj)
kfree(node->data);
kfree(node);
}
/**
* __of_prop_dup - Copy a property dynamically.
* @prop: Property to copy
* @allocflags: Allocation flags (typically pass GFP_KERNEL)
*
* 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_prop_dup(const struct property *prop, gfp_t allocflags)
{
struct property *new;
new = kzalloc(sizeof(*new), allocflags);
if (!new)
return NULL;
/*
* NOTE: There is no check for zero length value.
* In case of a boolean property This will allocate a value
* of zero bytes. We do this to work around the use
* of of_get_property() calls on boolean values.
*/
new->name = kstrdup(prop->name, allocflags);
new->value = kmemdup(prop->value, prop->length, allocflags);
new->length = prop->length;
if (!new->name || !new->value)
goto err_free;
/* mark the property as dynamic */
of_property_set_flag(new, OF_DYNAMIC);
return new;
err_free:
kfree(new->name);
kfree(new->value);
kfree(new);
return NULL;
}
/**
* __of_node_alloc() - Create an empty device node dynamically.
* @full_name: Full name of the new device node
* @allocflags: Allocation flags (typically pass GFP_KERNEL)
*
* 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_node_alloc(const char *full_name, gfp_t allocflags)
{
struct device_node *node;
node = kzalloc(sizeof(*node), allocflags);
if (!node)
return NULL;
node->full_name = kstrdup(full_name, allocflags);
of_node_set_flag(node, OF_DYNAMIC);
of_node_set_flag(node, OF_DETACHED);
if (!node->full_name)
goto err_free;
of_node_init(node);
return node;
err_free:
kfree(node->full_name);
kfree(node);
return NULL;
}
......@@ -51,4 +51,14 @@ static inline int of_property_notify(int action, struct device_node *np,
}
#endif /* CONFIG_OF_DYNAMIC */
/**
* 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.
*/
struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags);
struct device_node *__of_node_alloc(const char *full_name, gfp_t allocflags);
#endif /* _LINUX_OF_PRIVATE_H */
......@@ -16,6 +16,8 @@
#include <linux/slab.h>
#include <linux/device.h>
#include "of_private.h"
static struct selftest_results {
int passed;
int failed;
......@@ -266,6 +268,31 @@ static void __init of_selftest_property_match_string(void)
selftest(rc == -EILSEQ, "unterminated string; rc=%i", rc);
}
#define propcmp(p1, p2) (((p1)->length == (p2)->length) && \
(p1)->value && (p2)->value && \
!memcmp((p1)->value, (p2)->value, (p1)->length) && \
!strcmp((p1)->name, (p2)->name))
static void __init of_selftest_property_copy(void)
{
#ifdef CONFIG_OF_DYNAMIC
struct property p1 = { .name = "p1", .length = 0, .value = "" };
struct property p2 = { .name = "p2", .length = 5, .value = "abcd" };
struct property *new;
new = __of_prop_dup(&p1, GFP_KERNEL);
selftest(new && propcmp(&p1, new), "empty property didn't copy correctly\n");
kfree(new->value);
kfree(new->name);
kfree(new);
new = __of_prop_dup(&p2, GFP_KERNEL);
selftest(new && propcmp(&p2, new), "non-empty property didn't copy correctly\n");
kfree(new->value);
kfree(new->name);
kfree(new);
#endif
}
static void __init of_selftest_parse_interrupts(void)
{
struct device_node *np;
......@@ -533,6 +560,7 @@ static int __init of_selftest(void)
of_selftest_dynamic();
of_selftest_parse_phandle_with_args();
of_selftest_property_match_string();
of_selftest_property_copy();
of_selftest_parse_interrupts();
of_selftest_parse_interrupts_extended();
of_selftest_match_node();
......
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