Re: [RFC PATCH] crypto: flush poison data

Ben Dooks
2022-07-06T09:47:48Z

On 05/07/2022 17:42, Christoph Hellwig wrote:
> On Tue, Jul 05, 2022 at 10:21:13AM +0200, LABBE Corentin wrote:
>>
>> I just copied what did drivers/crypto/xilinx/zynqmp-sha.c.
>> I tried to do flush_dcache_range() but it seems to not be implemented on riscV.
>
> That driver is broken and should no have been merged in that form.
>
>> And flush_dcache_page(virt_to_page(addr), len) produce a kernel panic.
>
> And that's good so. Drivers have no business doing their own cache
> flushing. That is the job of the dma-mapping implementation, so I'd
> suggest to look for problems there.

I'm not sure that the dma-mapping code for non-coherent riscv systems
did get sorted. I couldn't find any when looking in 5.17.

I expect the flush of the icache is also implicitly doing a dcache
flush too as from what i've seen it is only being used when code or
tlbs are being modified.

--
Ben Dooks http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius