Re: [PATCH v5 4/4] crypto: Add Allwinner Security System crypto accelerator

[Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>]

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On Fri, Oct 31, 2014 at 06:05:22PM +0800, Herbert Xu wrote:
> On Fri, Oct 31, 2014 at 10:57:06AM +0100, Maxime Ripard wrote:
> >
> > On a 3.18-rc2 kernel:
> > 
> > $ git grep kmap -- crypto/
> > crypto/ahash.c:                         walk->data = kmap(walk->pg);
> > crypto/ahash.c:                         walk->data = kmap_atomic(walk->pg);
> > crypto/async_tx/async_memcpy.c:         dest_buf = kmap_atomic(dest) + dest_offset;
> > crypto/async_tx/async_memcpy.c:         src_buf = kmap_atomic(src) + src_offset;
> > crypto/scatterwalk.c:                   return kmap_atomic(scatterwalk_page(walk)) +
> > crypto/shash.c:                         data = kmap_atomic(sg_page(sg));
> > crypto/shash.c:                         data = kmap_atomic(sg_page(sg));
> > 
> > None of the drivers are.
> 
> What do you mean? It's precisely because the page can be in highmem
> that we are mapping it.  If it's not in highmem it'll be a noop.

What I mean is that since you are saying that drivers should do the
kmap themselves, then *all* of the drivers are broken if they are not
using it. And all of them are missing this kmap.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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