Re: [PATCH 04/13] resource: Provide new functions to walk through resources

Borislav Petkov
2014-06-04T10:24:46Z

On Tue, Jun 03, 2014 at 09:06:53AM -0400, Vivek Goyal wrote:
> @@ -322,7 +327,71 @@ int release_resource(struct resource *old)
>
> EXPORT_SYMBOL(release_resource);
>
> -#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY)
> +/*
> + * Finds the lowest iomem reosurce exists with-in [res->start.res->end)
> + * the caller must specify res->start, res->end, res->flags and "name".
> + * If found, returns 0, res is overwritten, if not found, returns -1.
> + * This walks through whole tree and not just first level children.
> + */
> +static int find_next_iomem_res(struct resource *res, char *name)
> +{
> + resource_size_t start, end;
> + struct resource *p;
> +
> + BUG_ON(!res);
> +
> + start = res->start;
> + end = res->end;
> + BUG_ON(start >= end);
> +
> + read_lock(&resource_lock);
> + p = &iomem_resource;
> + while ((p = next_resource(p))) {

Just a thought - this function differs from find_next_system_ram() only
in the traversal mode through resources. I wonder if next_resource()
could be given a flag, say TRAVERSE_SIBLINGS_ONLY or so and be called
from both, once with the flag set and once without and thus save us the
code duplication.

> + if (p->flags != res->flags)
> + continue;
> + if (name && strcmp(p->name, name))
> + continue;
> + if (p->start > end) {
> + p = NULL;
> + break;
> + }
> + if ((p->end >= start) && (p->start < end))
> + break;
> + }
> +
> + read_unlock(&resource_lock);
> + if (!p)
> + return -1;
> + /* copy data */
> + if (res->start < p->start)
> + res->start = p->start;
> + if (res->end > p->end)
> + res->end = p->end;
> + return 0;
> +}

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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