Re: [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN

Herbert Xu
2022-04-18T08:37:44Z

On Sun, Apr 17, 2022 at 05:30:27PM +0100, Catalin Marinas wrote:
>
> Do you mean as per Ard's proposal here:
>
> https://lore.kernel.org/r/CAMj1kXH0x5Va7Wgs+mU1ONDwwsazOBuN4z4ihVzO2uG-n41Kbg@mail.gmail.com
>
> struct crypto_request {
> union {
> struct {
> ... fields ...
> };
> u8 __padding[ARCH_DMA_MINALIGN];
> };
> void __ctx[] __aligned(CRYPTO_MINALIGN);
> };
>
> If CRYPTO_MINALIGN is lowered to, say, 8 (to be the same as lowest
> ARCH_KMALLOC_MINALIGN), the __alignof__(req->__ctx) would be 8.
> Functions like crypto_tfm_ctx_alignment() will return 8 when what you
> need is 128. We can change those functions to return ARCH_DMA_MINALIGN
> instead or always bump cra_alignmask to ARCH_DMA_MINALIGN-1.

OK, at this point I think we need to let the code do the talking :)

I've seen Ard's patches already and I think I understand what your
needs are. So let me whip up some code to show you guys what I
think needs to be done.

Please bear with me for a few days.

Thanks,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
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