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SubjectRe: [PATCH] kernel/resource: refine find_next_iomem_res() a little
Hello every one,

Someone would like to take a look at this?

On Tue, Mar 27, 2018 at 06:46:06AM +0800, Wei Yang wrote:
>This patch does several refine for find_next_iomem_res()
>
> * use first_level_children_only directly
> * remove some local variables
> * use resrouce_clip()
>
>Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>---
> kernel/resource.c | 40 +++++++++++++++-------------------------
> 1 file changed, 15 insertions(+), 25 deletions(-)
>
>diff --git a/kernel/resource.c b/kernel/resource.c
>index e270b5048988..769109f20fb7 100644
>--- a/kernel/resource.c
>+++ b/kernel/resource.c
>@@ -351,6 +351,15 @@ int release_resource(struct resource *old)
>
> EXPORT_SYMBOL(release_resource);
>
>+static void resource_clip(struct resource *res, resource_size_t min,
>+ resource_size_t max)
>+{
>+ if (res->start < min)
>+ res->start = min;
>+ if (res->end > max)
>+ res->end = max;
>+}
>+
> /*
> * Finds the lowest iomem resource existing within [res->start.res->end).
> * The caller must specify res->start, res->end, res->flags, and optionally
>@@ -361,31 +370,24 @@ EXPORT_SYMBOL(release_resource);
> static int find_next_iomem_res(struct resource *res, unsigned long desc,
> bool first_level_children_only)
> {
>- resource_size_t start, end;
> struct resource *p;
>- bool sibling_only = false;
>
> BUG_ON(!res);
>-
>- start = res->start;
>- end = res->end;
>- BUG_ON(start >= end);
>-
>- if (first_level_children_only)
>- sibling_only = true;
>+ BUG_ON(res->start >= res->end);
>
> read_lock(&resource_lock);
>
>- for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
>+ for (p = iomem_resource.child; p;
>+ p = next_resource(p, first_level_children_only)) {
> if ((p->flags & res->flags) != res->flags)
> continue;
> if ((desc != IORES_DESC_NONE) && (desc != p->desc))
> continue;
>- if (p->start > end) {
>+ if (p->start > res->end) {
> p = NULL;
> break;
> }
>- if ((p->end >= start) && (p->start < end))
>+ if ((p->end >= res->start) && (p->start < res->end))
> break;
> }
>
>@@ -393,10 +395,7 @@ static int find_next_iomem_res(struct resource *res, unsigned long desc,
> if (!p)
> return -1;
> /* copy data */
>- if (res->start < p->start)
>- res->start = p->start;
>- if (res->end > p->end)
>- res->end = p->end;
>+ resource_clip(res, p->start, p->end);
> res->flags = p->flags;
> res->desc = p->desc;
> return 0;
>@@ -600,15 +599,6 @@ static resource_size_t simple_align_resource(void *data,
> return avail->start;
> }
>
>-static void resource_clip(struct resource *res, resource_size_t min,
>- resource_size_t max)
>-{
>- if (res->start < min)
>- res->start = min;
>- if (res->end > max)
>- res->end = max;
>-}
>-
> /*
> * Find empty slot in the resource tree with the given range and
> * alignment constraints
>--
>2.15.1

--
Wei Yang
Help you, Help me

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