Re: [PATCH] crypto: sa2ul: Fix DMA mapping API usage

From: Peter Ujfalusi
Date: Wed Sep 23 2020 - 03:48:48 EST




On 23/09/2020 9.02, Christoph Hellwig wrote:
> On Mon, Sep 21, 2020 at 02:38:46PM +0300, Peter Ujfalusi wrote:
>> Make sure that we call the dma_unmap_sg on the correct scatterlist on
>> completion with the correct sg_nents.
>>
>> We also should be calling dma_sync_sg_for_device() on the tx buffer before
>> giving it to the DMA and the dma_sync_sg_for_cpu() should be called on the
>> scatterlist we received the data back.
>
> You might want to look into using struct sg_table and the DMA mapping
> helpers using it to simplify this a bit.

It would have simplified it a bit further if the dma_map_sgtable() would
have saved the dir we used when mapping (and then dma_unmap_sgtable()
would use the stored dir) and had a bool to tell that the mapping was
successful.

I'll send v2 with the use of sg_table in a bit after running some tests
to make sure it is working as expected. It is passing the extended boot
time tests on j721e.

- Péter

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