ACPI: scan: Add a weak arch_sort_irqchip_probe() to order the IRQCHIP probe

Unlike OF framework, the irqchip probe using IRQCHIP_ACPI_DECLARE has no
order defined. Depending on the Makefile is not a good idea. So,
usually it is worked around by mandating only root interrupt controller
probed using IRQCHIP_ACPI_DECLARE and other interrupt controllers are
probed via cascade mechanism.

However, this is also not a clean solution because if there are multiple
root controllers (ex: RINTC in RISC-V which is per CPU) which need to be
probed first, then the cascade will happen for every root controller.
So, introduce an architecture specific weak function
arch_sort_irqchip_probe() to order the probing of the interrupt
controllers which can be implemented by different architectures as per
their interrupt controller hierarchy.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://patch.msgid.link/20240812005929.113499-3-sunilvl@ventanamicro.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 22ae7829a9155de65c7154647f0c919f8f050073..607bbb8b90da18e884cecf61a86dc921531f1caa 100644 (file)
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2757,6 +2757,8 @@ static int __init acpi_match_madt(union acpi_subtable_headers *header,
        return 0;
 }
 
+void __weak arch_sort_irqchip_probe(struct acpi_probe_entry *ap_head, int nr) { }
+
 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
 {
        int count = 0;
@@ -2765,6 +2767,7 @@ int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
                return 0;
 
        mutex_lock(&acpi_probe_mutex);
+       arch_sort_irqchip_probe(ap_head, nr);
        for (ape = ap_head; nr; ape++, nr--) {
                if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
                        acpi_probe_count = 0;

diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 0687a442fec7d571f57a025492ad9345390ae63d..3fff86f95c2fb25330f783dd7d03cd159ecae9e7 100644 (file)
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1343,6 +1343,8 @@ struct acpi_probe_entry {
        kernel_ulong_t driver_data;
 };
 
+void arch_sort_irqchip_probe(struct acpi_probe_entry *ap_head, int nr);
+
 #define ACPI_DECLARE_PROBE_ENTRY(table, name, table_id, subtable,      \
                                 valid, data, fn)                       \
        static const struct acpi_probe_entry __acpi_probe_##name        \