arch/x86: Add register_new_ioapic()

Using this I/O APIC IDs will be assigned incrementally
in the order of calling. I/O APIC ID #0 is reserved for
the I/O APIC delivering GSI #0.

Change-Id: I6493dc3b4fa542e81f80bb0355eac6dad30b93ec
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55313
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

2 files changed, 15 insertions, 0 deletions

diff --git a/src/arch/x86/include/arch/ioapic.h b/src/arch/x86/include/arch/ioapic.h
index 9e524e250f..288f54cefc 100644
--- a/src/arch/x86/include/arch/ioapic.h
+++ b/src/arch/x86/include/arch/ioapic.h
@@ -37,6 +37,8 @@ void ioapic_set_max_vectors(void *ioapic_base, int mre_count);
 void ioapic_lock_max_vectors(void *ioapic_base);
 
 void setup_ioapic(void *ioapic_base, u8 ioapic_id);
+void register_new_ioapic(void *ioapic_base);
+void register_new_ioapic_gsi0(void *ioapic_base);
 
 void ioapic_set_boot_config(void *ioapic_base, bool irq_on_fsb);
 #endif
diff --git a/src/arch/x86/ioapic.c b/src/arch/x86/ioapic.c
index d65637c662..1440bb4331 100644
--- a/src/arch/x86/ioapic.c
+++ b/src/arch/x86/ioapic.c
@@ -163,3 +163,16 @@ void setup_ioapic(void *ioapic_base, u8 ioapic_id)
 	clear_vectors(ioapic_base, 0, ioapic_get_max_vectors(ioapic_base) - 1);
 	route_i8259_irq0(ioapic_base);
 }
+
+void register_new_ioapic_gsi0(void *ioapic_base)
+{
+	setup_ioapic(ioapic_base, 0);
+}
+
+void register_new_ioapic(void *ioapic_base)
+{
+	static u8 ioapic_id;
+	ioapic_id++;
+	set_ioapic_id(ioapic_base, ioapic_id);
+	clear_vectors(ioapic_base, 0, ioapic_get_max_vectors(ioapic_base) - 1);
+}