On Mon, 2013-04-08 at 11:01 +0900, Yasuaki Ishimatsu wrote:
> Hi Toshi,
>
> 2013/04/04 8:23, Toshi Kani wrote:
> > Added release_mem_region_adjustable(), which releases a requested
> > region from a currently busy memory resource. This interface
> > adjusts the matched memory resource accordingly if the requested
> > region does not match exactly but still fits into.
> >
> > This new interface is intended for memory hot-delete. During
> > bootup, memory resources are inserted from the boot descriptor
> > table, such as EFI Memory Table and e820. Each memory resource
> > entry usually covers the whole contigous memory range. Memory
> > hot-delete request, on the other hand, may target to a particular
> > range of memory resource, and its size can be much smaller than
> > the whole contiguous memory. Since the existing release interfaces
> > like __release_region() require a requested region to be exactly
> > matched to a resource entry, they do not allow a partial resource
> > to be released.
> >
> > There is no change to the existing interfaces since their restriction
> > is valid for I/O resources.
> >
> > Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>
>
> Reviewed-by : Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Great! Thanks Yasuaki!
> One nitpick below.
>
(snip)
> > +/**
> > + * release_mem_region_adjustable - release a previously reserved memory region
> > + * @parent: parent resource descriptor
> > + * @start: resource start address
> > + * @size: resource region size
> > + *
> > + * The requested region is released from a currently busy memory resource.
> > + * It adjusts the matched busy memory resource accordingly if the requested
> > + * region does not match exactly but still fits into. Existing children of
> > + * the busy memory resource must be immutable in this request.
> > + *
> > + * Note, when the busy memory resource gets split into two entries, the code
> > + * assumes that all children remain in the lower address entry for simplicity.
> > + * Enhance this logic when necessary.
> > + */
> > +int release_mem_region_adjustable(struct resource *parent,
> > + resource_size_t start, resource_size_t size)
> > +{
> > + struct resource **p;
> > + struct resource *res, *new;
> > + resource_size_t end;
> > + int ret = -EINVAL;
> > +
>
> > + end = start + size - 1;
> > + if ((start < parent->start) || (end > parent->end))
> > + return -EINVAL;
>
> "ret" is initialized to -EINVAL. So how about use it?
Sounds good. I will make the change.
Thanks again,
-Toshi
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