[RFC PATCH] of: make MAX_RESERVED_REGIONS configurable

Miles Chen
2018-11-22T02:51:28Z

On Wed, 2018-11-21 at 10:39 -0600, Rob Herring wrote:
> On Wed, Nov 21, 2018 at 2:11 AM <miles.chen@mediatek.com> wrote:
> >
> > From: Miles Chen <miles.chen@mediatek.com>
> >
> > When we use more than 32 entries in /resered-memory,
> > there will be an error message: "not enough space all defined regions.".
> > We can increase MAX_RESERVED_REGIONS to fix this.
> >
> > commit 22f8cc6e3373 ("drivers: of: increase MAX_RESERVED_REGIONS to 32")
> > increased MAX_RESERVED_REGIONS to 32 but I'm not sure if increasing
> > MAX_RESERVED_REGIONS to 64 is suitable for everyone.
> >
> > In this RFC patch, CONFIG_MAX_OF_RESERVED_REGIONS is added and used as
> > MAX_RESERVED_REGIONS. Add a sanity test to make sure that
> > MAX_RESERVED_REGIONS is less than INIT_MEMBLOCK_REGIONS.
> > Users can configure CONFIG_MAX_OF_RESERVED_REGIONS according to their
> > need.
>
> I don't want a kconfig option for this. I think it should be dynamic instead.
>
> The current flow is like this:
>
> for each reserved node:
> - call memblock_reserve
> - Add info to reserved_mem array
>
> I think we should change it to:
>
> for each reserved node:
> - call memblock_reserve
> - count number of nodes
>
> Alloc array using memblock_alloc
>
> for each reserved node:
> - Add info to reserved_mem array
>

thanks for your comment.

I reviewed the flow and it might be easier to count the
nodes and setup array first:

for each reserved node:
- count number of nodes

Alloc array using memblock_alloc

for each reserved node:
- call memblock_reserve
- Add info to reserved_mem array

What do you think?

> Rob