Re: [PATCH v4 2/5] powerpc/mm/slice: Enhance for supporting PPC32

From: Nicholas Piggin
Date: Sun Feb 11 2018 - 09:00:13 EST


On Sat, 10 Feb 2018 13:54:27 +0100 (CET)
Christophe Leroy <christophe.leroy@xxxxxx> 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.
>
> This patch moves "slices" functions prototypes from page64.h to slice.h
>
> The high slices use bitmaps. As bitmap functions are not prepared to
> handling bitmaps of size 0, the bitmap_xxx() calls are wrapped into
> slice_bitmap_xxx() functions which will void on PPC32

On this last point, I think it would be better to put these with the
existing slice bitmap functions in slice.c and just have a few #ifdefs
for SLICE_NUM_HIGH == 0.

Thanks,
Nick