Re: [PATCH] OF: Add [__]of_find_node_by_full_name

From: Rob Herring
Date: Wed Mar 19 2014 - 08:26:27 EST


On Tue, Mar 18, 2014 at 4:52 PM, Pantelis Antoniou
<pantelis.antoniou@xxxxxxxxxxxx> wrote:
> __of_find_node_by_full_name recursively searches for a matching node
> with the given full name without taking any locks.
>
> of_find_node_by_full_name takes locks and takes a reference on the
> matching node.
>
> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
> ---
> drivers/of/base.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/of.h | 4 ++++
> 2 files changed, 62 insertions(+)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 19bcdb4..08156e6 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -1142,6 +1142,64 @@ static void *of_find_property_value_of_size(const struct device_node *np,
> }
>
> /**
> + * __of_find_node_by_full_name - Find a node with the full name recursively
> + * @node: Root of the tree to perform the search
> + * @full_name: Full name of the node to find.
> + *
> + * Find a node with the give full name by recursively following any of
> + * the child node links.
> + * Returns the matching node, or NULL if not found.
> + * Note that the devtree lock is not taken, so this function is only
> + * safe to call on either detached trees, or when devtree lock is already
> + * taken.
> + */
> +struct device_node *__of_find_node_by_full_name(struct device_node *node,
> + const char *full_name)
> +{
> + struct device_node *child, *found;
> +
> + if (node == NULL)

Just !node is preferred.

> + return NULL;
> +
> + /* check */
> + if (of_node_cmp(node->full_name, full_name) == 0)
> + return node;
> +
> + __for_each_child_of_node(node, child) {
> + found = __of_find_node_by_full_name(child, full_name);
> + if (found != NULL)

"if (found)" is preferred.

> + return found;
> + }
> +
> + return NULL;
> +}
> +EXPORT_SYMBOL(__of_find_node_by_full_name);

Does this need to be exported?

In any case, use EXPORT_SYMBOL_GPL.

> +
> +/**
> + * of_find_node_by_full_name - Find a node with the full name recursively
> + * @node: Root of the tree to perform the search
> + * @full_name: Full name of the node to find.
> + *
> + * Find a node with the give full name by recursively following any of
> + * the child node links.
> + * Returns the matching node (with a ref taken), or NULL if not found.
> + */
> +struct device_node *of_find_node_by_full_name(struct device_node *node,
> + const char *full_name)
> +{
> + unsigned long flags;
> + struct device_node *np;
> +
> + raw_spin_lock_irqsave(&devtree_lock, flags);
> + np = of_find_node_by_full_name(node, full_name);

Don't you need __of_find_node_by_full_name here.

> + of_node_get(np);
> + raw_spin_unlock_irqrestore(&devtree_lock, flags);
> +
> + return np;
> +}
> +EXPORT_SYMBOL(of_find_node_by_full_name);
> +
> +/**
> * of_property_read_u32_index - Find and read a u32 from a multi-value property.
> *
> * @np: device node from which the property value is to be read.
> diff --git a/include/linux/of.h b/include/linux/of.h
> index a8b9dad..bef3d5b 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -223,6 +223,10 @@ extern struct device_node *of_find_matching_node_and_match(
>
> extern struct device_node *of_find_node_by_path(const char *path);
> extern struct device_node *of_find_node_by_phandle(phandle handle);
> +struct device_node *__of_find_node_by_full_name(struct device_node *node,
> + const char *full_name);
> +struct device_node *of_find_node_by_full_name(struct device_node *node,
> + const char *full_name);
> extern struct device_node *of_get_parent(const struct device_node *node);
> extern struct device_node *of_get_next_parent(struct device_node *node);
> extern struct device_node *of_get_next_child(const struct device_node *node,
> --
> 1.7.12
>
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