Re: [PATCH v2 09/10] target/ppc: Correct RMLS table

[David Gibson]

On Tue, Jan 07, 2020 at 03:21:42PM +0100, Cédric Le Goater wrote:
> On 1/7/20 5:48 AM, David Gibson wrote:
> > The table of RMA limits based on the LPCR[RMLS] field is slightly wrong.
> > We're missing the RMLS == 0 => 256 GiB RMA option, which is available on
> > POWER8, so add that.
> 
> Where is this defined ?

It's in the Book4, so not easily available, unfortunately :(.

> > The comment that goes with the table is much more wrong.  We *don't* filter
> > invalid RMLS values when writing the LPCR, and there's not really a
> > sensible way to do so.  Furthermore, while in theory the set of RMLS values
> > is implementation dependent, it seems in practice the same set has been
> > available since around POWER4+ up until POWER8, the last model which
> > supports RMLS at all.  So, correct that as well.
> > 
> > Signed-off-by: David Gibson <address@hidden>
> > ---
> >  target/ppc/mmu-hash64.c | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
> > index bb9ebeaf48..e6f24be93e 100644
> > --- a/target/ppc/mmu-hash64.c
> > +++ b/target/ppc/mmu-hash64.c
> > @@ -760,12 +760,12 @@ static target_ulong rmls_limit(PowerPCCPU *cpu)
> >  {
> >      CPUPPCState *env = &cpu->env;
> >      /*
> > -     * This is the full 4 bits encoding of POWER8. Previous
> > -     * CPUs only support a subset of these but the filtering
> > -     * is done when writing LPCR
> > +     * In theory the meanings of RMLS values are implementation
> > +     * dependent.  In practice, this seems to have been the set from
> > +     * POWER4+..POWER8, and RMLS is no longer supported in POWER9.
> >       */
> >      const target_ulong rma_sizes[] = {
> > -        [0] = 0,
> > +        [0] = 256 * GiB,
> >          [1] = 16 * GiB,
> >          [2] = 1 * GiB,
> >          [3] = 64 * MiB,
> > 
> 

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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