soc/intel/xeon_sp: Read ioapic configuration from hardware

This is more robust than hardcoding whathever FSP has set up and is a
lot less code.

Change-Id: I6423ddc139d742879d791b054ea082768749c0a7
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70265
Reviewed-by: Jonathan Zhang <jonzhang@fb.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/common/block/acpi/acpi.c

@@ -73,34 +73,26 @@ static unsigned long acpi_madt_irq_overrides(unsigned long current)
 	return current;
 }
 
-__weak const struct madt_ioapic_info *soc_get_ioapic_info(size_t *entries)
+static const uintptr_t default_ioapic_bases[] = { IO_APIC_ADDR };
+
+__weak size_t soc_get_ioapic_info(const uintptr_t *ioapic_bases[])
 {
-	*entries = 0;
-	return NULL;
+	*ioapic_bases = default_ioapic_bases;
+	return ARRAY_SIZE(default_ioapic_bases);
 }
 
 unsigned long acpi_fill_madt(unsigned long current)
 {
-	const struct madt_ioapic_info *ioapic_table;
+	const uintptr_t *ioapic_table;
 	size_t ioapic_entries;
 
 	/* Local APICs */
 	current = acpi_create_madt_lapics_with_nmis(current);
 
 	/* IOAPIC */
-	ioapic_table = soc_get_ioapic_info(&ioapic_entries);
-	if (ioapic_entries) {
-		for (int i = 0; i < ioapic_entries; i++) {
-			current += acpi_create_madt_ioapic(
-					(void *)current,
-					ioapic_table[i].id,
-					ioapic_table[i].addr,
-					ioapic_table[i].gsi_base);
-		}
-	} else {
-		/* Default SOC IOAPIC entry */
-		current += acpi_create_madt_ioapic_from_hw((void *)current, IO_APIC_ADDR);
-	}
+	ioapic_entries = soc_get_ioapic_info(&ioapic_table);
+	for (int i = 0; i < ioapic_entries; i++)
+		current += acpi_create_madt_ioapic_from_hw((void *)current, ioapic_table[i]);
 
 	return acpi_madt_irq_overrides(current);
 }

src/soc/intel/common/block/include/intelblocks/acpi.h

@@ -93,17 +93,11 @@ void soc_power_states_generation(int core_id, int cores_per_package);
  */
 int common_calculate_power_ratio(int tdp, int p1_ratio, int ratio);
 
-struct madt_ioapic_info {
-	u8  id;
-	u32 addr;
-	u32 gsi_base;
-};
 
 /*
- * Returns a table of MADT ioapic_info entries and the number of entries
- * If the SOC doesn't implement this hook a default ioapic setting is used.
+ * Return the number of table entries and takes a pointer to an array of ioapic bases.
  */
-const struct madt_ioapic_info *soc_get_ioapic_info(size_t *entries);
+size_t soc_get_ioapic_info(const uintptr_t *ioapic_bases[]);
 
 struct soc_pmc_lpm {
 	unsigned int num_substates;