On Tue, Jan 27, 2026 at 09:39:19AM +0100, Ahmad Fatoum wrote:
> resize_region allows enlarging or reducing a region end while checking
> for conflicts. This is less effort than removing a region and
> reallocating it.
>
> Signed-off-by: Ahmad Fatoum <[email protected]>
> ---
> common/resource.c | 45 ++++++++++++++++++++++++++++++++++++++++++
> include/linux/ioport.h | 2 ++
> 2 files changed, 47 insertions(+)
>
> diff --git a/common/resource.c b/common/resource.c
> index e391d268e0bb..39867da63b69 100644
> --- a/common/resource.c
> +++ b/common/resource.c
> @@ -92,6 +92,51 @@ struct resource *__request_region(struct resource *parent,
> return new;
> }
>
> +int resize_region(struct resource *res, resource_size_t size)
> +{
> + struct resource *parent;
> + struct resource *next;
> + resource_size_t newend;
> +
> + if (!res)
> + return 0;
> + if (!size)
> + return release_region(res);
This frees the resource itself. I am not sure if this is useful. It's an
invitation for the caller to reference freed memory. I think the caller
must distinguish between resizing and releasing the resource anyway, so
he could equally call resize_region() or release_region() directly.
> +
> + if (size == resource_size(res))
> + return 0;
> +
> + if (size < resource_size(res)) {
> + res->end = res->start + size - 1;
> + return 0;
> + }
A resource can have child resources. For completeness we should check if
the child resources are still inside the now smaller parent resource.
Sascha
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