[External] Re: [PATCH v4 2/3] riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTT

yunhui cui cuiyunhui at bytedance.com
Thu Apr 18 23:27:39 PDT 2024


Hi palmer,

On Thu, Apr 18, 2024 at 4:42 PM Sudeep Holla <sudeep.holla at arm.com> wrote:
>
> On Thu, Apr 18, 2024 at 11:43:29AM +0800, Yunhui Cui wrote:
> > Before cacheinfo can be built correctly, we need to initialize level
> > and type. Since RSIC-V currently does not have a register group that
> > describes cache-related attributes like ARM64, we cannot obtain them
> > directly, so now we obtain cache leaves from the ACPI PPTT table
> > (acpi_get_cache_info()) and set the cache type through split_levels.
> >
> > Suggested-by: Jeremy Linton <jeremy.linton at arm.com>
> > Suggested-by: Sudeep Holla <sudeep.holla at arm.com>
> > Signed-off-by: Yunhui Cui <cuiyunhui at bytedance.com>
> > ---
> >  arch/riscv/kernel/cacheinfo.c | 22 ++++++++++++++++++++++
> >  1 file changed, 22 insertions(+)
> >
> > diff --git a/arch/riscv/kernel/cacheinfo.c b/arch/riscv/kernel/cacheinfo.c
> > index 30a6878287ad..e47a1e6bd3fe 100644
> > --- a/arch/riscv/kernel/cacheinfo.c
> > +++ b/arch/riscv/kernel/cacheinfo.c
> > @@ -6,6 +6,7 @@
> >  #include <linux/cpu.h>
> >  #include <linux/of.h>
> >  #include <asm/cacheinfo.h>
> > +#include <linux/acpi.h>
> >
> >  static struct riscv_cacheinfo_ops *rv_cache_ops;
> >
> > @@ -78,6 +79,27 @@ int populate_cache_leaves(unsigned int cpu)
> >       struct device_node *prev = NULL;
> >       int levels = 1, level = 1;
> >
> > +     if (!acpi_disabled) {
> > +             int ret, fw_levels, split_levels;
> > +
> > +             ret = acpi_get_cache_info(cpu, &fw_levels, &split_levels);
> > +             if (ret)
> > +                     return ret;
> > +
> > +             BUG_ON((split_levels > fw_levels) ||
> > +                    (split_levels + fw_levels > this_cpu_ci->num_leaves));
> > +
> > +             for (; level <= this_cpu_ci->num_levels; level++) {
> > +                     if (level <= split_levels) {
> > +                             ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
> > +                             ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
> > +                     } else {
> > +                             ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
> > +                     }
> > +             }
> > +             return 0;
> > +     }
> > +
>
> Much better, so my review still stands 😄
>
> Reviewed-by: Sudeep Holla <sudeep.holla at arm.com>
>
> >       if (of_property_read_bool(np, "cache-size"))
> >               ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
> >       if (of_property_read_bool(np, "i-cache-size"))
> > --
> > 2.20.1
> >
>
> --
> Regards,
> Sudeep

Do you have any comments about this patch series?

Thanks,
Yunhui



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