Re: [PATCH -v2 5/5] crypto: Add PCLMULQDQ accelerated GHASHimplementation

From: Huang Ying
Date: Thu Aug 06 2009 - 03:20:35 EST


On Thu, 2009-08-06 at 15:17 +0800, Herbert Xu wrote:
> On Mon, Aug 03, 2009 at 03:45:31PM +0800, Huang Ying wrote:
> > PCLMULQDQ is used to accelerate the most time-consuming part of GHASH,
> > carry-less multiplication. More information about PCLMULQDQ can be
> > found at:
> >
> > http://software.intel.com/en-us/articles/carry-less-multiplication-and-its-usage-for-computing-the-gcm-mode/
> >
> > Because PCLMULQDQ changes XMM state, its usage must be enclosed with
> > kernel_fpu_begin/end, which can be used only in process context, the
> > acceleration is implemented as crypto_ahash. That is, request in soft
> > IRQ context will be defered to the cryptd kernel thread.
> >
> > Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
>
> Please resubmit this patch once irq_is_fpu_using() hits mainline.

OK. I will do that.

Best Regards,
Huang Ying

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