Re: [PATCH v18 7/7] firmware: arm_rmm: Add wrappers for Realm related RMI commands

[Suzuki K Poulose]

On 15/09/2026 20:35, Alper Gun wrote:
> On Sat, Sep 12, 2026 at 1:37 AM Suzuki K Poulose <suzuki.poulose@xxxxxxx> wrote:
> [...]
> > +/**
> > + * rmi_rtt_destroy() - Destroy an RTT
> > + * @rd: PA of the RD
> > + * @ipa: Base of the IPA range described by the RTT
> > + * @level: RTT level
> > + * @out_rtt: Pointer to write the PA of the RTT which was destroyed
> > + * @out_top: Pointer to write the top IPA of non-live RTT entries, from entry
> > + * at which the RTT walk terminated.
> > + *
> > + * Destroys an RTT. The RTT must be non-live, i.e. none of the entries in the
> > + * table are in ASSIGNED or TABLE state.
> > + *
> > + * Return: 0 on success, positive RMI result code or negative Linux error code.
> > + */
> > +static inline long rmi_rtt_destroy(unsigned long rd,
> > +                                  unsigned long ipa,
> > +                                  long level,
> > +                                  unsigned long *out_rtt,
> > +                                  unsigned long *out_top)
> > +{
> > +       struct arm_smccc_1_2_regs regs = {
> > +               SMC_RMI_RTT_DESTROY, rd, ipa, level
> > +       };
> > +       long ret = rmi_sro_execute(&regs);
> > +
> > +       if (ret != RMI_SUCCESS)
> > +               return ret;
> > +
> > +       if (out_rtt)
> > +               *out_rtt = regs.a1;
> > +       if (out_top)
> > +               *out_top = regs.a2;
> > +
> > +       return RMI_SUCCESS;
> > +}
>
> Doesn't out_top (regs.a2) need to be populated on RMI_ERROR_RTT as well?
> realm_tear_down_rtt_level() checks next_addr > addr under case
> RMI_ERROR_RTT: to determine whether the RTT is missing or has child tables
> that need recursive teardown.

You're right. The out_top is valid even when we get RMI_ERROR_RTT. I
will fix it.

Cheers
Suzuki

> Thanks,
> Alper