On Tue, Mar 02, 2021 at 09:51:28AM +0530, Bharata B Rao wrote:
> On Tue, Mar 02, 2021 at 12:28:34PM +1100, David Gibson wrote:
> > On Wed, Feb 24, 2021 at 01:55:08PM +0530, Bharata B Rao wrote:
> > > Add a field to mmu_psize_def to store the page size encodings
> > > of H_RPT_INVALIDATE hcall. Initialize this while scanning the radix
> > > AP encodings. This will be used when invalidating with required
> > > page size encoding in the hcall.
> > >
> > > Signed-off-by: Bharata B Rao <bharata@xxxxxxxxxxxxx>
> > > ---
> > > arch/powerpc/include/asm/book3s/64/mmu.h | 1 +
> > > arch/powerpc/mm/book3s64/radix_pgtable.c | 5 +++++
> > > 2 files changed, 6 insertions(+)
> > >
> > > diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
> > > index eace8c3f7b0a..c02f42d1031e 100644
> > > --- a/arch/powerpc/include/asm/book3s/64/mmu.h
> > > +++ b/arch/powerpc/include/asm/book3s/64/mmu.h
> > > @@ -19,6 +19,7 @@ struct mmu_psize_def {
> > > int penc[MMU_PAGE_COUNT]; /* HPTE encoding */
> > > unsigned int tlbiel; /* tlbiel supported for that page size */
> > > unsigned long avpnm; /* bits to mask out in AVPN in the HPTE */
> > > + unsigned long h_rpt_pgsize; /* H_RPT_INVALIDATE page size encoding */
> > > union {
> > > unsigned long sllp; /* SLB L||LP (exact mask to use in slbmte) */
> > > unsigned long ap; /* Ap encoding used by PowerISA 3.0 */
> > > diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
> > > index 98f0b243c1ab..1b749899016b 100644
> > > --- a/arch/powerpc/mm/book3s64/radix_pgtable.c
> > > +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
> > > @@ -486,6 +486,7 @@ static int __init radix_dt_scan_page_sizes(unsigned long node,
> > > def = &mmu_psize_defs[idx];
> > > def->shift = shift;
> > > def->ap = ap;
> > > + def->h_rpt_pgsize = psize_to_rpti_pgsize(idx);
> > > }
> > >
> > > /* needed ? */
> > > @@ -560,9 +561,13 @@ void __init radix__early_init_devtree(void)
> > > */
> > > mmu_psize_defs[MMU_PAGE_4K].shift = 12;
> > > mmu_psize_defs[MMU_PAGE_4K].ap = 0x0;
> > > + mmu_psize_defs[MMU_PAGE_4K].h_rpt_pgsize =
> > > + psize_to_rpti_pgsize(MMU_PAGE_4K);
> >
> > Hm. TBH, I was thinking of this as replacing psize_to_rpti_pgsize() -
> > that is, you directly put the correct codes in there, then just have
> > psize_to_rpti_pgsize() look them up in the table.
> >
> > I guess that could be a followup change, though.
> >
> > >
> > > mmu_psize_defs[MMU_PAGE_64K].shift = 16;
> > > mmu_psize_defs[MMU_PAGE_64K].ap = 0x5;
> > > + mmu_psize_defs[MMU_PAGE_64K].h_rpt_pgsize =
> > > + psize_to_rpti_pgsize(MMU_PAGE_64K);
>
> Hmm if you see I got rid of rpti_pgsize_to_psize() by having the
> defines directly in mmu_psize_def[].
I realize that, but I'm talking about the reverse direction:
psize_to_rpti_pgsize(). You should be able to reduce it a table
lookup, so the mmu_psize_defs table is the only place this information
exists.
> There are two cases in the above code (radix__early_init_devtree)
>
> 1. If radix pagesize encodings are present in the DT, we walk
> the page sizes in the loop and populate the enconding for
> H_RPT_INVALIDATE. I am not sure if we can use the direct codes
> in this case.
I'm not understanding the problem.
In any case the existing implementation of psize
Why ever not? You can just update the mmu_psize_defs when you parse
the device tree. Plus AFAICT, the existing psize_to_rpti
implementation doesn't take into account any device tree eencodings.
> 2. If DT doesn't have the radix pagesize encodings, 4K and 64K
> sizes are assumed as fallback sizes where we can use direct
> encodings.
Right... still not seeing the problem.
--
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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