Re: [PATCH for-7.2 v3 18/20] device_node.c: enable 'info fdt' to print subnodes

[David Gibson]

On Tue, Aug 16, 2022 at 02:34:26PM -0300, Daniel Henrique Barboza wrote:
> Printing subnodes of a given node will allow us to show a whole subtree,
> which the additional perk of 'info fdt /' being able to print the whole
> FDT.
> 
> Since we're now printing more than one subnode, change 'fdt_info' to
> print the full path of the first node. This small tweak helps
> identifying which node or subnode are being displayed.
> 
> To demostrate this capability without printing the whole FDT, the
> '/cpus/cpu-map' node from the ARM 'virt' machine has a lot of subnodes:
> 
> (qemu) info fdt /cpus/cpu-map
> /cpus/cpu-map {
>     socket0 {
>         cluster0 {
>             core0 {
>                 cpu = <0x8001>
>             }
>         }
>     }
> }

nit: dts format requires a ; after each closing }
        foo {
                bar {
                };
        };

> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
> ---
>  softmmu/device_tree.c | 21 +++++++++++++++++----
>  1 file changed, 17 insertions(+), 4 deletions(-)
> 
> diff --git a/softmmu/device_tree.c b/softmmu/device_tree.c
> index 43f96e371b..a6bfbc0617 100644
> --- a/softmmu/device_tree.c
> +++ b/softmmu/device_tree.c
> @@ -766,17 +766,26 @@ static void fdt_prop_format_val(GString *buf, const 
> char *propname,
>      g_string_append_printf(buf, "];\n");
>  }
>  
> -static void fdt_format_node(GString *buf, int node, int depth)
> +
> +static void fdt_format_node(GString *buf, int node, int depth,
> +                            const char *fullpath)
>  {
>      const struct fdt_property *prop = NULL;
> +    const char *nodename = NULL;
>      const char *propname = NULL;
>      void *fdt = current_machine->fdt;
>      int padding = depth * 4;
>      int property = 0;
> +    int parent = node;
>      int prop_size;
>  
> -    g_string_append_printf(buf, "%*s%s {\n", padding, "",
> -                           fdt_get_name(fdt, node, NULL));
> +    if (fullpath != NULL) {
> +        nodename = fullpath;
> +    } else {
> +        nodename = fdt_get_name(fdt, node, NULL);
> +    }
> +
> +    g_string_append_printf(buf, "%*s%s {\n", padding, "", nodename);
>  
>      padding += 4;
>  
> @@ -801,6 +810,10 @@ static void fdt_format_node(GString *buf, int node, int 
> depth)
>          }
>      }
>  
> +    fdt_for_each_subnode(node, fdt, parent) {
> +        fdt_format_node(buf, node, depth + 1, NULL);
> +    }
> +
>      padding -= 4;
>      g_string_append_printf(buf, "%*s}\n", padding, "");
>  }
> @@ -821,7 +834,7 @@ HumanReadableText *qemu_fdt_qmp_query_fdt(const char 
> *nodepath, Error **errp)
>          return NULL;
>      }
>  
> -    fdt_format_node(buf, node, 0);
> +    fdt_format_node(buf, node, 0, nodepath);
>  
>      return human_readable_text_from_str(buf);
>  }

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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