diff --git a/include/acpi/actbl3.h b/include/acpi/actbl3.h
index f12f4bb1907b..ebc1f4f9fe66 100644
--- a/include/acpi/actbl3.h
+++ b/include/acpi/actbl3.h
@@ -481,7 +481,8 @@ struct acpi_table_pcct {
 enum acpi_pcct_type {
 	ACPI_PCCT_TYPE_GENERIC_SUBSPACE = 0,
 	ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE = 1,
-	ACPI_PCCT_TYPE_RESERVED = 2	/* 2 and greater are reserved */
+	ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2 = 2,	/* ACPI 6.1 */
+	ACPI_PCCT_TYPE_RESERVED = 3	/* 3 and greater are reserved */
 };
 
 /*
@@ -520,6 +521,26 @@ struct acpi_pcct_hw_reduced {
 	u16 min_turnaround_time;
 };
 
+/* 2: HW-reduced Communications Subspace Type 2 (ACPI 6.1) */
+
+struct acpi_pcct_hw_reduced_type2 {
+	struct acpi_subtable_header header;
+	u32 doorbell_interrupt;
+	u8 flags;
+	u8 reserved;
+	u64 base_address;
+	u64 length;
+	struct acpi_generic_address doorbell_register;
+	u64 preserve_mask;
+	u64 write_mask;
+	u32 latency;
+	u32 max_access_rate;
+	u16 min_turnaround_time;
+	struct acpi_generic_address doorbell_ack_register;
+	u64 ack_preserve_mask;
+	u64 ack_write_mask;
+};
+
 /* Values for doorbell flags above */
 
 #define ACPI_PCCT_INTERRUPT_POLARITY    (1)