Re: [PATCH v3 0/2] of: reserved_mem: use dynamically allocated reserved_mem array

[Rob Herring <robh@kernel.org>]

On Thu, Oct 15, 2026 at 10:23:10AM +0200, Marek Szyprowski wrote:
> Mike Rapoport suggested [1] how to properly use dynamically allocated
> arrays during early boot.
> 
> Use this approach for reserved_mem array during early scan of the
> reserved regions. Having all the reserved regions in a single array
> removes the need of the two pass initialization introduced by commit
> 8a6e02d0c00e ("of: reserved_mem: Restructure how the reserved memory
> regions are processed"), so implement it to make the code simpler,
> easier to understand and ready for adding proper error checking.
> 
> Tested on ARM32, ARM64 and RiscV64 based boards. Arch specific issues
> with early mappings were discovered by LLM.
> 
> [1] https://lore.kernel.org/all/asc6brs_g0ky0wOM@kernel.org/
> 
> 
> Best regards
> Marek Szyprowski, PhD
> Samsung R&D Institute Poland
> 
> 
> Changelog:
> 
> v3:
> - allocate the reserved_mem array only after all static regions are
>   reserved or marked as no-map, so it cannot be placed inside any of
>   them
> - record failures of the early static reservations and print a single
>   message asking to fix the device-tree
> - restore conditional compilation of the early mapping code, because
>   some architectures lack support for it (C-SKY & Sparc64 as reported
>   by kbuild robot)
> - allocate the array bottom-up, to avoid allocating from highmem, what
>   might be an issue on Xtensa, C-SKY and MIPS32
> - don't use the early mapping on PPC64, where the scan is done before
>   early_ioremap_setup()
> 
> v2: https://lore.kernel.org/all/20261008152403.766439-1-m.szyprowski@samsung.com/
> - removed superfluous ifdefs
> 
> v1: https://lore.kernel.org/all/20261008094125.3197971-1-m.szyprowski@samsung.com/
> - initial version
> 
> 
> Patch summary:
> 
> Marek Szyprowski (2):
>   of: reserved_mem: group allocation helpers together
>   of: reserved_mem: allocate and map the reserved_mem array early

Can you confirm the sashiko issues are not issues?

I'll apply this after rc1. Are you willing to be added as reviewer or 
maintainer for this code? I'd prefer not to have another entry just for 
the reserved mem code, so you'd have to filter out the rest of the DT 
code (not the bindings and dts firehose) which isn't too much.

Rob