diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index 9967291178bb..72c194e2991e 100644
--- a/drivers/acpi/pptt.c
+++ b/drivers/acpi/pptt.c
@@ -281,6 +281,37 @@ static struct acpi_pptt_processor *acpi_find_processor_node(struct acpi_table_he
 	return NULL;
 }
 
+/* parent_node points into the table, but the table isn't provided. */
+void acpi_pptt_get_child_cpus(struct acpi_pptt_processor *parent_node, cpumask_t *cpus)
+{
+	struct acpi_pptt_processor *cpu_node;
+	struct acpi_table_header *table_hdr;
+	acpi_status status;
+	u32 acpi_id;
+	int cpu;
+
+	status = acpi_get_table(ACPI_SIG_PPTT, 0, &table_hdr);
+	if (ACPI_FAILURE(status))
+		return;
+
+	for_each_possible_cpu(cpu) {
+		acpi_id = get_acpi_id_for_cpu(cpu);
+		cpu_node = acpi_find_processor_node(table_hdr, acpi_id);
+
+		while (cpu_node) {
+			if (cpu_node == parent_node) {
+				cpumask_set_cpu(cpu, cpus);
+				break;
+			}
+			cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);
+		}
+	}
+
+	acpi_put_table(table_hdr);
+
+	return;
+}
+
 /**
  * acpi_pptt_for_each_container() - Iterate over all processor containers
  *
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 36be818f8433..387de2ab57f6 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1364,6 +1364,7 @@ int find_acpi_cpu_topology_hetero_id(unsigned int cpu);
 int find_acpi_cpu_cache_topology(unsigned int cpu, int level);
 u32 acpi_pptt_count_containers(void);
 int acpi_pptt_for_each_container(acpi_pptt_cpu_callback_t callback, void *arg);
+void acpi_pptt_get_child_cpus(struct acpi_pptt_processor *parent_node, cpumask_t *cpus);
 #else
 static inline int acpi_pptt_cpu_is_thread(unsigned int cpu)
 {
@@ -1394,6 +1395,11 @@ acpi_pptt_for_each_container(acpi_pptt_cpu_callback_t *callback, void *arg)
 {
 	return -EINVAL;
 }
+static inline void
+acpi_pptt_get_child_cpus(struct acpi_pptt_processor *parent_node,
+			 cpumask_t *cpus)
+{
+}
 #endif
 
 #ifdef CONFIG_ACPI