Re: [PATCH v1 1/2] resource: Introduce resource_rebase() helper

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Wed, 3 Sep 2025, Andy Shevchenko wrote:

> Introduce a helper to add an offset to the resource. This is helpful
> in the cases when, for example) the resource has statically defined
> the start and end fields, but the base of it is yet to be defined,
> usually dynamically at run-time.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  include/linux/ioport.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/include/linux/ioport.h b/include/linux/ioport.h
> index e8b2d6aa4013..159e74284d0b 100644
> --- a/include/linux/ioport.h
> +++ b/include/linux/ioport.h
> @@ -290,6 +290,12 @@ static inline resource_size_t resource_size(const struct resource *res)
>  {
>  	return res->end - res->start + 1;
>  }
> +
> +static inline void resource_rebase(struct resource *res, resource_size_t start)
> +{
> +	resource_set_range(res, start + res->start, resource_size(res));
> +}

Hi Andy,

This seems fine, it's nice to get rid of complex ->end calculations. But I 
wanted to mention another common case which is resetting the base to zero.
Are we expected to use resource_rebase() for those cases too? I've been 
thinking of adding something like resource_reset().

resource_rebase(res, 0) would work for those cases but it doesn't then  
carry the intent of "removing" the base in its name. Opinions?

-- 
 i.