soc/intel: Introduce ioapic_get_sci_pin()

According to ACPI Release 6.5 systems supporting PIC (i8259)
interrupt mechanism need to report IRQ vector for the SCI_INT
field. In PIC mode only IRQ0..15 are allowed hardware vectors.

This change should cover section 5.2.9 to not pass SCI_INT
larger than IRQ15. Section 5.2.15.5 needs follow-up work.

Care should be taken that ioapic_get_sci_pin() is called
after platform code has potentially changed the routing
from the default.

It appears touched all platforms except siemens/mc_aplX
currently program SCI as IRQ9.

Change-Id: I723c207f1dcbba5e6fc0452fe1dbd087fad290ee
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/74326
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <inforichland@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

1 files changed, 38 insertions, 0 deletions

diff --git a/src/acpi/acpi.c b/src/acpi/acpi.c
index 25409295fc..a2865cbf7e 100644
--- a/src/acpi/acpi.c
+++ b/src/acpi/acpi.c
@@ -17,6 +17,7 @@
 #include <acpi/acpi_ivrs.h>
 #include <acpi/acpigen.h>
 #include <arch/hpet.h>
+#include <arch/smp/mpspec.h>
 #include <cbfs.h>
 #include <cbmem.h>
 #include <commonlib/helpers.h>
@@ -225,6 +226,24 @@ int acpi_create_madt_ioapic_from_hw(acpi_madt_ioapic_t *ioapic, u32 addr)
 }
 #endif
 
+u16 acpi_sci_int(void)
+{
+#if ENV_X86
+	u8 gsi, irq, flags;
+
+	ioapic_get_sci_pin(&gsi, &irq, &flags);
+
+	/* ACPI Release 6.5, 5.2.9 and 5.2.15.5. */
+	if (!CONFIG(ACPI_HAVE_PCAT_8259))
+		return gsi;
+
+	assert(irq < 16);
+	return irq;
+#else
+	return 0;
+#endif
+}
+
 int acpi_create_madt_irqoverride(acpi_madt_irqoverride_t *irqoverride,
 		u8 bus, u8 source, u32 gsirq, u16 flags)
 {
@@ -238,6 +257,25 @@ int acpi_create_madt_irqoverride(acpi_madt_irqoverride_t *irqoverride,
 	return irqoverride->length;
 }
 
+int acpi_create_madt_sci_override(acpi_madt_irqoverride_t *irqoverride)
+{
+	u8 gsi, irq, flags;
+
+	ioapic_get_sci_pin(&gsi, &irq, &flags);
+
+	if (!CONFIG(ACPI_HAVE_PCAT_8259))
+		irq = gsi;
+
+	irqoverride->type = IRQ_SOURCE_OVERRIDE; /* Interrupt source override */
+	irqoverride->length = sizeof(acpi_madt_irqoverride_t);
+	irqoverride->bus = MP_BUS_ISA;
+	irqoverride->source = irq;
+	irqoverride->gsirq = gsi;
+	irqoverride->flags = flags;
+
+	return irqoverride->length;
+}
+
 static int acpi_create_madt_lapic_nmi(acpi_madt_lapic_nmi_t *lapic_nmi, u8 cpu,
 				u16 flags, u8 lint)
 {