Re: [RFC PATCH] of: make MAX_RESERVED_REGIONS configurable

[Rob Herring]

On Wed, Nov 21, 2018 at 2:11 AM <miles.chen@xxxxxxxxxxxx> wrote:
>
> From: Miles Chen <miles.chen@xxxxxxxxxxxx>
>
> 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

Rob