Re: [PATCH v16 2/9] irqchip: Add RISC-V incoming MSI controller early driver

[Eric Cheng]

On 4/19/2024 11:44 AM, Anup Patel wrote:
> On Fri, Apr 19, 2024 at 8:53 AM Eric Cheng <eric.cheng.linux@xxxxxxxxx> wrote:
> > On 3/7/2024 10:03 PM, Anup Patel wrote:
> >
> > > +static int __init imsic_parse_fwnode(struct fwnode_handle *fwnode,
> > > +                                  struct imsic_global_config *global,
> > > +                                  u32 *nr_parent_irqs,
> > > +                                  u32 *nr_mmios)
> > > +{
> >
> > ...
> >
> > > +     /*
> > > +      * Find first bit position of group index.
> > > +      * If not specified assumed the default APLIC-IMSIC configuration.
> > > +      */
> > > +     rc = of_property_read_u32(to_of_node(fwnode), "riscv,group-index-shift",
> > > +                               &global->group_index_shift);
> > > +     if (rc)
> > > +             global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
> > > +
> > > +     /* Find number of interrupt identities */
> > > +     rc = of_property_read_u32(to_of_node(fwnode), "riscv,num-ids",
> > > +                               &global->nr_ids);
> >
> > Will here check if the pass-in interrupt identity number is (multi-64 -1) &&
> > between [63, 2047]?
> > Per spec AIA v1.0, Sec. 3.1 Interrupt files and interrupt identities:
> > "The number of interrupt identities supported by an interrupt file (and hence
> > the number of active
> > bits in each array) is one less than a multiple of 64, and may be a minimum of
> > 63 and a maximum
> > of 2047."
>
> There is already a check on global->nr_ids to ensure the above is satisfied.
> Please see further below in imsic_parse_fwnode() function.

Right, thanks.
> > > +     if (rc) {
> > > +             pr_err("%pfwP: number of interrupt identities not found\n", fwnode);
> > > +             return rc;
> > > +     }
> > > +
> > ...
>
> Regards,
> Anup