Re: [PATCH v1 1/9] RISC-V: don't parse dt/acpi isa string to get rv32/rv64

Andrew Jones
2023-06-26T16:05:54Z

On Mon, Jun 26, 2023 at 04:51:29PM +0100, Conor Dooley wrote:
> On Mon, Jun 26, 2023 at 05:14:15PM +0200, Andrew Jones wrote:
> > On Mon, Jun 26, 2023 at 12:19:39PM +0100, Conor Dooley wrote:
> > > From: Heiko Stuebner <heiko.stuebner@vrull.eu>
> > > @@ -333,8 +335,6 @@ static int c_show(struct seq_file *m, void *v)
> > >
> > > of_node_put(node);
> > > } else {
> > > - if (!acpi_get_riscv_isa(NULL, cpu_id, &isa))
> > > - print_isa(m, isa);
> > >
> >
> > Extra blank line here to remove. Actually the whole 'else' can be removed
> > because the print_mmu() call can be brought up above the
> > 'if (acpi_disabled)'
>
> Can it be? I intentionally did not make that change - wasn't sure
> whether re-ordering the fields in there was permissible.

I agree we shouldn't change the order, but moving print_mmu() up won't,
afaict.

>
> One of the few things I know does parsing of /proc/cpuinfo is:
> https://github.com/google/cpu_features/blob/main/src/impl_riscv_linux.c
> and that doesn't seem to care about the mmu, but does rely on
> vendor/uarch ordering.
>
> Makes me wonder, does ACPI break things by leaving out uarch/vendor
> fields, if there is something that expects them to exist? We should
> not intentionally break stuff in /proc/cpuinfo, but can't say I feel any
> sympathy for naively parsing it.

Yes, it would be nice for ACPI to be consistent. I'm not sure what can be
done about that.

Thanks,
drew

>
> > > print_mmu(m);