Re: [PATCH] kernel, resource: use resource_overlaps() to simplify region_intersects()

[Like Xu]

On 2019/2/12 8:13, Wei Yang wrote:
> On Mon, Jan 21, 2019 at 09:20:28AM +0800, Wei Yang wrote:
> > The three checks in region_intersects() is to see whether two resources
> > overlap. This means it could be simplified with one resource_overlaps().
> >
> > Also fix two typo in related function.
> >
> > Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
>
> Hello~
>
> Would someone like to take a look?

No semantic change and it looks good to me.

Reviewed-by: Like Xu <like.xu@xxxxxxxxxxxxxxx>

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> > ---
> > kernel/iomem.c    |  4 ++--
> > kernel/resource.c | 11 +++++------
> > 2 files changed, 7 insertions(+), 8 deletions(-)
> >
> > diff --git a/kernel/iomem.c b/kernel/iomem.c
> > index f7525e14ebc6..93c264444510 100644
> > --- a/kernel/iomem.c
> > +++ b/kernel/iomem.c
> > @@ -55,7 +55,7 @@ static void *try_ram_remap(resource_size_t offset, size_t size,
> >   *
> >   * MEMREMAP_WB - matches the default mapping for System RAM on
> >   * the architecture.  This is usually a read-allocate write-back cache.
> > - * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM
> > + * Moreover, if MEMREMAP_WB is specified and the requested remap region is RAM
> >   * memremap() will bypass establishing a new mapping and instead return
> >   * a pointer into the direct map.
> >   *
> > @@ -86,7 +86,7 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags)
> > 	/* Try all mapping types requested until one returns non-NULL */
> > 	if (flags & MEMREMAP_WB) {
> > 		/*
> > -		 * MEMREMAP_WB is special in that it can be satisifed
> > +		 * MEMREMAP_WB is special in that it can be satisfied
> > 		 * from the direct map.  Some archs depend on the
> > 		 * capability of memremap() to autodetect cases where
> > 		 * the requested range is potentially in System RAM.
> > diff --git a/kernel/resource.c b/kernel/resource.c
> > index b0fbf685c77a..34dfb94305bb 100644
> > --- a/kernel/resource.c
> > +++ b/kernel/resource.c
> > @@ -521,21 +521,20 @@ EXPORT_SYMBOL_GPL(page_is_ram);
> > int region_intersects(resource_size_t start, size_t size, unsigned long flags,
> > 		      unsigned long desc)
> > {
> > -	resource_size_t end = start + size - 1;
> > +	struct resource res;
> > 	int type = 0; int other = 0;
> > 	struct resource *p;
> >
> > +	res.start = start;
> > +	res.end = start + size - 1;
> > +
> > 	read_lock(&resource_lock);
> > 	for (p = iomem_resource.child; p ; p = p->sibling) {
> > 		bool is_type = (((p->flags & flags) == flags) &&
> > 				((desc == IORES_DESC_NONE) ||
> > 				 (desc == p->desc)));
> >
> > -		if (start >= p->start && start <= p->end)
> > -			is_type ? type++ : other++;
> > -		if (end >= p->start && end <= p->end)
> > -			is_type ? type++ : other++;
> > -		if (p->start >= start && p->end <= end)
> > +		if (resource_overlaps(p, &res))
> > 			is_type ? type++ : other++;
> > 	}
> > 	read_unlock(&resource_lock);
> > --
> > 2.19.1