static acpi_status acpi_map_iosapic()

in kernel/acpi.c [828:871]

• 32 lines of code
• 10 McCabe index (conditional complexity)

static acpi_status acpi_map_iosapic(acpi_handle handle, u32 depth,
				    void *context, void **ret)
{
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
	struct acpi_madt_io_sapic *iosapic;
	unsigned int gsi_base;
	int node;

	/* Only care about objects w/ a method that returns the MADT */
	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
		return AE_OK;

	if (!buffer.length || !buffer.pointer)
		return AE_OK;

	obj = buffer.pointer;
	if (obj->type != ACPI_TYPE_BUFFER ||
	    obj->buffer.length < sizeof(*iosapic)) {
		kfree(buffer.pointer);
		return AE_OK;
	}

	iosapic = (struct acpi_madt_io_sapic *)obj->buffer.pointer;

	if (iosapic->header.type != ACPI_MADT_TYPE_IO_SAPIC) {
		kfree(buffer.pointer);
		return AE_OK;
	}

	gsi_base = iosapic->global_irq_base;

	kfree(buffer.pointer);

	/* OK, it's an IOSAPIC MADT entry; associate it with a node */
	node = acpi_get_node(handle);
	if (node == NUMA_NO_NODE || !node_online(node) ||
	    cpumask_empty(cpumask_of_node(node)))
		return AE_OK;

	/* We know a gsi to node mapping! */
	map_iosapic_to_node(gsi_base, node);
	return AE_OK;
}