On 10/03/2015 05:04 AM, Marc Zyngier wrote:
On Fri, 2 Oct 2015 16:06:05 -0500 Wei Huang wei@redhat.com 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).
Yes, this approach would be sufficient. So users can clearly tell them apart in terms of usage cases.
Thanks, -Wei
Thanks,
M.