Re: [GIT PULL] ARM: mvebu: dt64 for v7.2 (#1)

[Aleksander Jan Bajkowski <olek2@wp.pl>]

Hi Arnd,

On 09/06/2026 21:29, Arnd Bergmann wrote:
> On Tue, Jun 9, 2026, at 19:35, Aleksander Jan Bajkowski wrote:
>> On 09/06/2026 18:11, Arnd Bergmann wrote:
>>> I'm a bit surprised by this oneline change. Since you successfully tested
>>> this, I assume the change is correct, but I have two questions that
>>> I would like to have an answer for before I pull it.
>> By the way, the upstream safexcel driver works correctly only on
>> coherent
>> platforms. On non-coherent platforms (MediaTek), the SHA-384 and SHA-512
>> selftests fail. Since the selftests pass on Armada's SoC, I assume I'm
>> right.
> It's not necessarily proof that this is correct, but it is quite likely.
>
> After checking the datasheet some more and finding that this should
> indeed be coherent everywhere, I remembered that even the old
> 32-bit Armada 370 had a coherency manager. At the time, we used a hack
> in  arch/arm/mach-mvebu/coherency.c to mark all device nodes as coherent,
> since the original DTB did not contain the correct annotations.
>
> I suspect that the Armada 37xx started out with a copy of the
> old DT files and also never had the annotation, but then never
> had the same hack because arch/arm64 does not have platform
> specific code.
>
>> I have a plan to send a patch upstream, which has long been maintained
>> downstream in OpenWRT[1]. But I need to think a bit more about how to do
>> this properly.
>> [1]
>> https://github.com/openwrt/openwrt/blob/main/target/linux/mediatek/patches-6.18/401-crypto-fix-eip97-cache-incoherent.patch
> The patch is basically correct, I think you should just change two
> details:
>
> - instead of defining your own SYSTEM_CACHELINE_SIZE macro, just use
>    the existing CRYPTO_DMA_ALIGN macro that is used in crypto_dma_align
>
> - move the 'state[]' and 'cache[]' arrays to the beginning of
>    safexcel_ahash_req so you don't have to manually align them.

My biggest concern is the increased memory overhead. On Marvell
platforms, this increases the structure size by 150 bytes. I’ve
checked, and both CRYPTO_DMA_ALIGN and ARCH_DMA_MINALIGN always
have a value of 128. On MIPS platforms, ARCH_DMA_MINALIGN is set
per SoC in the mach files. I assume that on a Marvell platform
with coherent DMA, I should set the value to 4, and on a
non-coherent MediaTek platform, to 64. How should this be handled
on an ARM platform?

Best Regards,
Aleksander