Re: c-r4k.c cleanup

[Nigel Stephens <nigel@mips.com>]

Atsushi Nemoto wrote:

> This code is wrong (should be "c->dcache.waysize > PAGE_SIZE") and
> unnecessary (done correctly in probe_pcache).
>
> diff -u -r1.96 c-r4k.c
> --- arch/mips/mm/c-r4k.c        7 Dec 2004 02:33:02 -0000       1.96
> +++ arch/mips/mm/c-r4k.c        4 Feb 2005 14:01:35 -0000
> @@ -1213,9 +1213,6 @@
>         probe_pcache();
>         setup_scache();
>
> -       if (c->dcache.sets * c->dcache.ways > PAGE_SIZE)
> -               c->dcache.flags |= MIPS_CACHE_ALIASES;
> -
>         r4k_blast_dcache_page_setup();
>         r4k_blast_dcache_page_indexed_setup();
>         r4k_blast_dcache_setup();
>
>
> Also, some MIPS32/MIPS64 chip have physically indexed data cache so do
> no suffer from aliasing.  CPU_20KC is one of them.  Others?
>  
The MIPS 24K family's caches are not physically indexed, but they do 
have optional h/w assist to prevent aliases in certain cache 
configurations. This optional feature is indicated by the read-only AR 
(alias removed) flag being set - that's bit 16 in the CP0 Config7 register.
Nigel