On Fri, 2 Oct 2015 16:06:05 -0500
Wei Huang <[email protected]> wrote:

Hi Wei,

> Hi Marc,

[...]

> > +struct acpi_probe_entry {
> > +   __u8 id[ACPI_TABLE_ID_LEN];
> > +   __u8 type;
> > +   acpi_probe_entry_validate_subtbl subtable_valid;
> > +   union {
> > +           acpi_tbl_table_handler probe_table;
> > +           acpi_tbl_entry_handler probe_subtbl;
> > +   };
> 
> Could we avoid using union for probe_table & probe_subtbl? The benefit is 
> that we don't need to do function casting below and compiler can 
> automatically check the correctness.
> 
> > +   kernel_ulong_t driver_data;
> > +};
> > +
> > +#define ACPI_DECLARE_PROBE_ENTRY(table, name, table_id, subtable, valid, 
> > data, fn) \
> > +   static const struct acpi_probe_entry __acpi_probe_##name        \
> > +           __used __section(__##table##_acpi_probe_table)          \
> > +            = {                                                    \
> > +                   .id = table_id,                                 \
> > +                   .type = subtable,                               \
> > +                   .subtable_valid = valid,                        \
> > +                   .probe_table = (acpi_tbl_table_handler)fn,      \
> > +                   .driver_data = data,                            \
> > +              }
> > +
> 
> Something like: 
> 
> #define ACPI_DECLARE_PROBE_ENTRY(table, name, table_id, subtable, valid, 
> data, fn, subfn)     \
>       static const struct acpi_probe_entry __acpi_probe_##name        \
>               __used __section(__##table##_acpi_probe_table)          \
>                = {                                                    \
>                       .id = table_id,                                 \
>                       .type = subtable,                               \
>                       .subtable_valid = valid,                        \
>                       .probe_table = fn,                              \
>                       .probe_subtbl = subfn,                          \
>                       .driver_data = data,                            \
>                  }
> 
> Then in patch 3, you can define new entries as:
> 
> IRQCHIP_ACPI_DECLARE(gic_v2, ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
>                    gic_validate_dist, ACPI_MADT_GIC_VERSION_V2,
>                    NULL, gic_v2_acpi_init);
> IRQCHIP_ACPI_DECLARE(gic_v2_maybe, ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
>                    gic_validate_dist, ACPI_MADT_GIC_VERSION_NONE,
>                    NULL, gic_v2_acpi_init);
> 

That's exactly what I was trying to avoid. If you want to do that, do
it in the IRQCHIP_ACPI_DECLARE macro, as there is strictly no need for
this this NULL to appear here (MADT always matches by subtable).

Or even better, have two ACPI_DECLARE* that populate the probe entry in
a mutually exclusive way (either probe_table is set and both
valid/subtbl are NULL, or probe_table is NULL and the two other fields
are set).

Thanks,

        M.
-- 
Jazz is not dead. It just smells funny.
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