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Date: Sat, 24 Feb 2018 17:47:44 +1000
From: Nicholas Piggin <npiggin@gmail.com>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras
 <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au>, Scott Wood
 <oss@buserror.net>, aneesh.kumar@linux.vnet.ibm.com,
 linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v5 3/6] powerpc/mm/slice: Enhance for supporting PPC32
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On Thu, 22 Feb 2018 15:27:24 +0100 (CET)
Christophe Leroy <christophe.leroy@c-s.fr> wrote:

> In preparation for the following patch which will fix an issue on
> the 8xx by re-using the 'slices', this patch enhances the
> 'slices' implementation to support 32 bits CPUs.
> 
> On PPC32, the address space is limited to 4Gbytes, hence only the low
> slices will be used.
> 
> The high slices use bitmaps. As bitmap functions are not prepared to
> handle bitmaps of size 0, this patch ensures that bitmap functions
> are called only when SLICE_NUM_HIGH is not nul.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

This looks good to me, thank you for taking my feedback into account.

Is the patch split and naming good? Yes I guess so, this adds support
for ppc32 archs that select PPC_MM_SLICES, and the next one implements
it for 8xx. There looks to be some generic arch/powerpc/mm bits in the
next patch. I wonder if you would move them over? Then the next patch
could be called powerpc/8xx: ?

Anyway it's not a big deal.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>