Re: [PATCH v9 02/10] of: reserved_mem: Introduce "ll-map" property

[Vincent Donnefort]

On Wed, Sep 02, 2026 at 12:24:36PM -0500, Rob Herring wrote:
> On Wed, Sep 02, 2026 at 11:47:04AM +0100, Vincent Donnefort wrote:
> > Keeping last-level mappings is interesting on some architectures as it
> > allows mapping/unmapping pages from the kernel direct map without the
> > risk of splitting blocks which, under the break-before-make rule, may
> > trigger page-faults the kernel can't handle.
> > 
> > Add an "ll-map" property for reserved-memory regions. When set, it
> > splits the underlying memblock and sets the MEMBLOCK_LLMAP flag.
> 
> Where is this documented? Any DT property must have a schema.

Ack.

> 
> Though I'm not thrilled about more flag properties. Handling all the 
> combinations of properties has proven to be painful. Can this be implied 
> from the compatible string instead?
> 
> Rob

We need this before the kernel direct map has been created (paging_init()).

I would have moved that directly into the driver lend_pool.c, but then it is
probed too late (unflatten_device_tree()).

-- 
Vincent