Re: [Qemu-devel] [QEMU-PPC] [PATCH] target/ppc: Add ibm, purr and ibm, spurr device-tree properties

[David Gibson <david@gibson.dropbear.id.au>]

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On Tue, May 07, 2019 at 09:43:34AM +1000, Suraj Jitindar Singh wrote:
> On Mon, 2019-05-06 at 13:23 +1000, David Gibson wrote:
> > On Mon, May 06, 2019 at 11:48:03AM +1000, Suraj Jitindar Singh wrote:
> > > The ibm,purr and ibm,spurr device tree properties are used to
> > > indicate
> > > that the processor implements the Processor Utilisation of
> > > Resources
> > > Register (PURR) and Scaled Processor Utilisation of Resources
> > > Registers
> > > (SPURR), respectively. Each property has a single value which
> > > represents
> > > the level of architecture supported. A value of 1 for ibm,purr
> > > means
> > > support for the version of the PURR defined in book 3 in version
> > > 2.02 of
> > > the architecture. A value of 1 for ibm,spurr means support for the
> > > version of the SPURR defined in version 2.05 of the architecture.
> > > 
> > > Add these properties for all processors for which the PURR and
> > > SPURR
> > > registers are generated.
> > 
> > So.. what does the current empty property mean?  Is it just wrong by
> > spec, or does it actually mean something incorrect?
> 
> Af far as I can tell, an empty property is invalid according to PAPR.
> A level value is required to communicate the level of purr
> implemented.

Ok, makes sense.  Applied.

> 
> Should probably have:
> 
> Fixes: 0da6f3fef9a "spapr: Reorganize CPU dt generation code"

I've folded that in.

> 
> > 
> > > 
> > > Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
> > > ---
> > >  hw/ppc/spapr.c | 5 ++++-
> > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > > index 2ef3ce4362..8580a8dc67 100644
> > > --- a/hw/ppc/spapr.c
> > > +++ b/hw/ppc/spapr.c
> > > @@ -500,7 +500,10 @@ static void spapr_populate_cpu_dt(CPUState
> > > *cs, void *fdt, int offset,
> > >      _FDT((fdt_setprop(fdt, offset, "64-bit", NULL, 0)));
> > >  
> > >      if (env->spr_cb[SPR_PURR].oea_read) {
> > > -        _FDT((fdt_setprop(fdt, offset, "ibm,purr", NULL, 0)));
> > > +        _FDT((fdt_setprop_cell(fdt, offset, "ibm,purr", 1)));
> > > +    }
> > > +    if (env->spr_cb[SPR_SPURR].oea_read) {
> > > +        _FDT((fdt_setprop_cell(fdt, offset, "ibm,spurr", 1)));
> > >      }
> > >  
> > >      if (ppc_hash64_has(cpu, PPC_HASH64_1TSEG)) {
> > 
> > 
> 

-- 
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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