[PATCH] firmware: scmi: Drop mmu_set_region_dcache_behaviour() misuse

[Marek Vasut]

On 10/28/25 9:25 AM, Peng Fan wrote:

Hello Peng,

>> Subject: [PATCH] firmware: scmi: Drop
>> mmu_set_region_dcache_behaviour() misuse
>>
>> MMU region cache behavior configuration for SCMI/SMT mailboxes is
>> platform specific. Even on ARM systems, the mailbox memory may not
>> even be located in any cacheable MMU region and may instead reside
>> in some SRAM. Remove this non-generic cache behavior configuration
>> code from generic code path.
>>
>> It is unlikely that any platform is affected by this change if it did
>> configure its MMU regions correctly on start up. Platforms which might
>> be affected are i.MX94/95 and STM32MP.
>>
> 
> If the memory is mapped before running SCMI stuff, it is ok.
> But if memory is dynamic mapped at run time, there might be issue.

I wonder ... should ARM/ARM64 define CONFIG_HAVE_ARCH_IOREMAP and 
implement actual ioremap() function which changes these cacheable 
properties accordingly ?

> I saw TI platforms has some changes to use dynamic mappings,
> I have not read the details, TBH.

Can we put the TI people on CC here ?

-- 
Best regards,
Marek Vasut