Re: [RFC PATCH] crypto: flush poison data

From: Ben Dooks
Date: Wed Jul 06 2022 - 05:47:51 EST


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

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