[PATCH] lmb: Reinstate access to memory above ram_top

[Marek Vasut]

On 2/9/26 7:45 PM, Casey Connolly wrote:

Hello Casey,

>> Which means, before we can really start switching boards to relocate to
>> 64bit space, we need to find all these remaining 32bit limitation sites
>> and fix them first. And to do that, we would need some way to force
>> allocation from 32bit space for drivers which need that ... do we
>> already have such a thing ? I couldn't find anything.
> 
> For some (non-upstream) Qualcomm drivers we have just used lmb with
> LMB_ALLOC_MAX and passed in 4GB as the max address, it would be nice to
> have a wrapper function for this.
> 
> Maybe this would just cause a whole bunch of other issues but perhaps it
> would be easiest to have a config option to place the malloc arena in
> 32-bit memory rather than always directly below U-Boot? Then again I
> imagine this is something that has been bikeshed in the past...

Are those qualcomm devices suffering from 32bit DMA limitation too ?

> *casey grumbles something about making relocation optional and merging
> the f/r init sequences for most boards*

Can you try CONFIG_SKIP_RELOCATE for your use case ?