On Thu, 2017-06-22 at 15:44 -0500, Rob Herring wrote:
> From: Pantelis Antoniou <[email protected]>
>
> 90% of the usage of device node's full_name is printing it out in a
> kernel message. However, storing the full path for every node is
> wasteful and redundant. With a custom format specifier, we can generate
> the full path at run-time and eventually remove the full path from every
> node.
>
> For instance typical use is:
> pr_info("Frobbing node %s\n", node->full_name);
>
> Which can be written now as:
> pr_info("Frobbing node %pOF\n", node);
I still think this should use another identifier like
%pO for object then another letter for type of object
maybe N for node.
And F is flags, f is name
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
[]
> @@ -1470,6 +1471,131 @@ char *flags_string(char *buf, char *end, void
> *flags_ptr, const char *fmt)
> return format_flags(buf, end, flags, names);
> }
>
> +static int device_node_calc_depth(const struct device_node *np)
> +{
> + int d;
> +
> + for (d = 0; np; d++)
> + np = np->parent;
> +
> + return d;
> +}
> +
> +static noinline_for_stack
> +char *device_node_gen_full_name(const struct device_node *np, char *buf,
> char *end)
> +{
> + int i;
> + int depth = device_node_calc_depth(np);
> + static const struct printf_spec strspec = {
> + .field_width = -1,
> + .precision = -1,
> + };
> + const struct device_node *nodes[depth];
> +
> + if (!depth)
> + returnuf;
> + /* special case for root node */
> + if (depth == 1)
> + return string(buf, end, "/", strspec);
> +
> + depth--;
> + for (i = depth - 1; i >= 0; i--) {
> + nodes[i] = np;
> + np = np->parent;
> + }
> + for (i = 0; i < depth; i++) {
> + buf = string(buf, end, "/", strspec);
> + buf = string(buf, end, kbasename(nodes[i]->full_name), strspec);
> + }
> + return buf;
> +}
I think there should be another function to get
a particular struct device_node * at a particular
depth to avoid all the pointers on stack.
Basically, adapt the for (i = depth - 1 loop to
a function that returns nodes[i]
