Re: [OpenBIOS] r579 - trunk/openbios-devel/modules

[Segher Boessenkool]

> +#ifdef CONFIG_PPC
> flush_icache_range( addr, addr + size );
>
> +#endif

I'm not sure what your flush_icache_range() does exactly, but at a
minimum it is misnamed: you need to flush the dcache for this range
to memory (dcbst is enough), do a sync, invalidate the icache (icbi),
do another sync, do an isync.

Segher

r579 - trunk/openbios-devel/modules

[Laurent Vivier]

Le samedi 19 septembre 2009 à 11:37 +0200, Segher Boessenkool a écrit :
> > +#ifdef CONFIG_PPC
> > flush_icache_range( addr, addr + size );
> >
> > +#endif
>
> I'm not sure what your flush_icache_range() does exactly, but at a

It is not mine ;-)
> minimum it is misnamed: you need to flush the dcache for this range
> to memory (dcbst is enough), do a sync, invalidate the icache (icbi),
> do another sync, do an isync.

It does exacly what you explain, see arch/ppc/qemu/start.S:

#define CACHE_LINE_SIZE         32
#define LG_CACHE_LINE_SIZE      5

/* flush_icache_range( ulong start, ulong stop) */
GLOBL(flush_icache_range):
        li      r5,CACHE_LINE_SIZE-1
        andc    r3,r3,r5
        subf    r4,r3,r4
        add     r4,r4,r5
        srwi.   r4,r4,LG_CACHE_LINE_SIZE
        beqlr
        mtctr   r4
        mr      r6,r3
1:      dcbst   0,r3
        addi    r3,r3,CACHE_LINE_SIZE
        bdnz    1b
        sync                            /* wait for dcbst's to get to
ram */
        mtctr   r4
2:      icbi    0,r6
        addi    r6,r6,CACHE_LINE_SIZE
        bdnz    2b
        sync                            /* additional sync needed on g4
*/
        isync
        blr

Regards,
Laurent

r579 - trunk/openbios-devel/modules

[Segher Boessenkool]

> > I'm not sure what your flush_icache_range() does exactly, but at a
>
> It is not mine ;-)

"your", as in "not mine" :-)
> > minimum it is misnamed: you need to flush the dcache for this range
> > to memory (dcbst is enough), do a sync, invalidate the icache (icbi),
> > do another sync, do an isync.
>
> It does exacly what you explain, see arch/ppc/qemu/start.S:

Excellent, so it is just misnamed; it says neither what it does nor
what its purpose is.  Oh well.

Segher

r579 - trunk/openbios-devel/modules

[Stefan Reinauer]

Segher Boessenkool wrote:
> > > minimum it is misnamed: you need to flush the dcache for this range
> > > to memory (dcbst is enough), do a sync, invalidate the icache (icbi),
> > > do another sync, do an isync.
> >
> > It does exacly what you explain, see arch/ppc/qemu/start.S:
>
> Excellent, so it is just misnamed; it says neither what it does nor
> what its purpose is.  Oh well.
>
> Segher

Hi Segher,

Patches and suggestions are welcome.

Stefan

r579 - trunk/openbios-devel/modules

[Segher Boessenkool]

> > > > minimum it is misnamed: you need to flush the dcache for this range
> > > > to memory (dcbst is enough), do a sync, invalidate the icache  
> > > > (icbi),
> > > > do another sync, do an isync.
> > >
> > > It does exacly what you explain, see arch/ppc/qemu/start.S:
> >
> > Excellent, so it is just misnamed; it says neither what it does nor
> > what its purpose is.  Oh well.
> Patches and suggestions are welcome.

Patches?  Hahahaha.

Suggestions?  Something like "synchronise icache", I dunno.  Making up
good names is hard work.

Segher