Re: [PATCH v2 3/4] powerpc: Add Power12 architected mode

[Mahesh J Salgaonkar <mahesh@linux.ibm.com>]

On 2026-08-04 11:50:45 Tue, Amit Machhiwal wrote:
> On 2026/08/04 11:30 AM, Mahesh J Salgaonkar wrote:
> > On 2026-08-04 00:47:49 Tue, Amit Machhiwal wrote:
> > > On 2026/08/03 09:27 PM, Mahesh Salgaonkar wrote:
> > > > From: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
> > > > 
> > > > PVR value of 0x0f000008 means we are arch v3.2 compliant (i.e.
> > > > Power12). This is used by phyp and kvm when booting as a pseries guest
> > > > to detect the presence of new Power12 features and to enable the
> > > > appropriate hwcap and facility bits.
> > > > 
> > > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > > > Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
> > > > Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
> > > > Tested-by: Praveen K Pandey <praveen@linux.ibm.com>
> > > > Reviewed-by: Nikhil Kumar Singh <nikhilks@linux.ibm.com>
> > > > ---
> > > >  arch/powerpc/include/asm/prom.h           |  1 +
> > > >  arch/powerpc/include/uapi/asm/cputable.h  |  1 +
> > > >  arch/powerpc/kernel/cpu_specs_book3s_64.h | 14 ++++++++++++++
> > > >  arch/powerpc/kernel/prom_init.c           | 12 ++++++++++--
> > > >  4 files changed, 26 insertions(+), 2 deletions(-)
> > > > 
> > > > diff --git a/arch/powerpc/include/asm/prom.h b/arch/powerpc/include/asm/prom.h
> > > > index f4991d10d89ec..cd025c7225ee7 100644
> > > > --- a/arch/powerpc/include/asm/prom.h
> > > > +++ b/arch/powerpc/include/asm/prom.h
> > > > @@ -118,6 +118,7 @@ extern unsigned int boot_cpu_node_count;
> > > >  
> > > >  #define OV1_PPC_3_00		0x80	/* set if we support PowerPC 3.00 */
> > > >  #define OV1_PPC_3_1			0x40	/* set if we support PowerPC 3.1 */
> > > > +#define OV1_PPC_3_2			0x20	/* set if we support PowerPC 3.2 */
> > > 
> > > Minor: OV1_PPC_3_1 and OV1_PPC_3_2 use extra tabs relative to OV1_PPC_3_00.
> > > This is pre-existing style inconsistency in the file (not introduced by
> > > this patch) but new additions should match the surrounding code. Please
> > > consider aligning them.
> > 
> > This is bit tricky. Prior to 3.0 the ISA versions were 2.05, 2.06, 2.07
> > and so on and pre-existing style did make sense. But it looks like from
> > 3.1 the style changed may be for a reason because it can not be written
> > as 3.10 which may create more confusiton. Hence, I plan to stick with
> > the new style which is introduced from 3.1.
> 
> If the extra tab is intentional to maintain visual alignment for the 3.x
> series names, then it make sense. Please feel free to add:

Ouch I missed that. thanks for the catch. Fixing it in v3

> 
> Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>

Thanks for your review.
-Mahesh.

> 
> Thanks,
> Amit
> 
> 

-- 
Mahesh J Salgaonkar