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Message-ID: <ec401a51-5895-fce7-1075-a2c964466d2b@codethink.co.uk>
Date:   Wed, 6 Jul 2022 10:47:24 +0100
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Subject: Re: [RFC PATCH] crypto: flush poison data
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To:     Christoph Hellwig <hch@lst.de>,
        LABBE Corentin <clabbe@baylibre.com>
Cc:     herbert@gondor.apana.org.au, heiko@sntech.de,
        linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-riscv@lists.infradead.org, linux-sunxi@lists.linux.dev
References: <20220701132735.1594822-1-clabbe@baylibre.com>
 <4570f6d8-251f-2cdb-1ea6-c3a8d6bb9fcf@codethink.co.uk> <YsP0eekTthD4jWGV@Red>
 <20220705164213.GA14484@lst.de>
From:   Ben Dooks <ben.dooks@codethink.co.uk>
Organization: Codethink Limited.
In-Reply-To: <20220705164213.GA14484@lst.de>
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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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