Re: [PATCH] of: add node name compare helper functions

From: Frank Rowand
Date: Tue Sep 04 2018 - 23:20:29 EST


On 08/30/18 11:52, Rob Herring wrote:
> In preparation to remove device_node.name pointer, add helper functions
> for node name comparisons which are a common pattern throughout the kernel.
>
> Cc: Frank Rowand <frowand.list@xxxxxxxxx>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> drivers/of/base.c | 22 ++++++++++++++++++++++
> include/linux/of.h | 13 +++++++++++++
> 2 files changed, 35 insertions(+)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 466e3c8582f0..185bfe077d0a 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -54,6 +54,28 @@ DEFINE_MUTEX(of_mutex);
> */
> DEFINE_RAW_SPINLOCK(devtree_lock);
>
> +bool of_node_name_eq(const struct device_node *np, const char *name)
> +{
> + const char *node_name;
> + size_t len;
> +
> + if (!np)
> + return false;
> +
> + node_name = kbasename(np->full_name);
> + len = strchrnul(node_name, '@') - node_name;
> +
> + return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
> +}
> +
> +bool of_node_name_prefix(const struct device_node *np, const char *prefix)

of_node_name_prefix_eq() would be more clear and consistent.

of_node_name_prefix() sounds like it would return the prefix of *np.


> +{
> + if (!np)
> + return false;
> +
> + return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
> +}
> +
> int of_n_addr_cells(struct device_node *np)
> {
> u32 cells;
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 4d25e4f952d9..a40f63a36afa 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -256,6 +256,9 @@ static inline unsigned long of_read_ulong(const __be32 *cell, int size)
> #define OF_IS_DYNAMIC(x) test_bit(OF_DYNAMIC, &x->_flags)
> #define OF_MARK_DYNAMIC(x) set_bit(OF_DYNAMIC, &x->_flags)
>
> +extern bool of_node_name_eq(const struct device_node *np, const char *name);
> +extern bool of_node_name_prefix(const struct device_node *np, const char *prefix);
> +
> static inline const char *of_node_full_name(const struct device_node *np)
> {
> return np ? np->full_name : "<no-node>";
> @@ -561,6 +564,16 @@ static inline struct device_node *to_of_node(const struct fwnode_handle *fwnode)
> return NULL;
> }
>
> +static inline bool of_node_name_eq(const struct device_node *np, const char *name)
> +{
> + return false;
> +}
> +
> +static inline bool of_node_name_prefix(const struct device_node *np, const char *prefix)
> +{
> + return false;
> +}
> +
> static inline const char* of_node_full_name(const struct device_node *np)
> {
> return "<no-node>";
>