Re: [RFC PATCH 7/8] ppc/spapr: strip OF path argument suffix in path_offset

[Narayana Murty N <nnmlinux@linux.ibm.com>]

Hi Utkarsh,

On 17/08/26 3:57 PM, uverma@linux.ibm.com wrote:
> From: Utkarsh Verma <uverma@linux.ibm.com>
> 
> OF paths can include a ":argument" suffix on the last component (e.g.
> "disk@8000000000000000:0"), which is an OF path argument such as a
> partition number.  This is not part of the FDT node name and causes
> fdt_path_offset() to fail.
> 
> Strip any ":<suffix>" from the last path component only, leaving
> intermediate components untouched.
> 
> AI-used-for: code
> Signed-off-by: Utkarsh Verma <uverma@linux.ibm.com>
> ---
>   hw/ppc/vof.c | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
> 
> diff --git a/hw/ppc/vof.c b/hw/ppc/vof.c
> index b1c574aabf..d3b0df30e4 100644
> --- a/hw/ppc/vof.c
> +++ b/hw/ppc/vof.c
> @@ -142,6 +142,8 @@ static int path_offset(const void *fdt, const char *path)
>   {
>       g_autofree char *p = NULL;
>       char *at;
> +    char *last_slash;
> +    char *colon;
>   
>       /*
>        * https://www.devicetree.org/open-firmware/bindings/ppc/release/ppc-2_1.html#HDR16
> @@ -151,6 +153,20 @@ static int path_offset(const void *fdt, const char *path)
>        * suppressing leading zeros".
>        */
>       p = g_strdup(path);
> +
> +    /*
> +     * Strip any ":argument" suffix from the last path component (e.g.
> +     * "disk@8000000000000000:0") — it is an OF path argument, not part of
> +     * the FDT node name.
> +     */
> +    last_slash = strrchr(p, '/');
> +    if (last_slash) {
> +        colon = strchr(last_slash, ':');
> +        if (colon) {
> +            *colon = '\0';
> +        }
> +    }
Is path_offset() guaranteed to always receive an absolute path?

If not, paths without /, such as disk@8000000000000000:0, won't have the 
suffix stripped. Either document the absolute-path requirement or handle 
the no-slash case as well.

Thanks,
Narayana Murty N
> +
>       for (at = strchr(p, '@'); at && *at; ) {
>               if (*at == '/') {
>                   at = strchr(at, '@');