diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index 442995b..4de3c69 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -437,6 +437,7 @@
 /* HMI interrupt event */
 enum OpalHMI_Version {
 	OpalHMIEvt_V1 = 1,
+	OpalHMIEvt_V2 = 2,
 };
 
 enum OpalHMI_Severity {
@@ -467,6 +468,49 @@
 	OpalHMI_ERROR_CAPP_RECOVERY,
 };
 
+enum OpalHMI_XstopType {
+	CHECKSTOP_TYPE_UNKNOWN	=	0,
+	CHECKSTOP_TYPE_CORE	=	1,
+	CHECKSTOP_TYPE_NX	=	2,
+};
+
+enum OpalHMI_CoreXstopReason {
+	CORE_CHECKSTOP_IFU_REGFILE		= 0x00000001,
+	CORE_CHECKSTOP_IFU_LOGIC		= 0x00000002,
+	CORE_CHECKSTOP_PC_DURING_RECOV		= 0x00000004,
+	CORE_CHECKSTOP_ISU_REGFILE		= 0x00000008,
+	CORE_CHECKSTOP_ISU_LOGIC		= 0x00000010,
+	CORE_CHECKSTOP_FXU_LOGIC		= 0x00000020,
+	CORE_CHECKSTOP_VSU_LOGIC		= 0x00000040,
+	CORE_CHECKSTOP_PC_RECOV_IN_MAINT_MODE	= 0x00000080,
+	CORE_CHECKSTOP_LSU_REGFILE		= 0x00000100,
+	CORE_CHECKSTOP_PC_FWD_PROGRESS		= 0x00000200,
+	CORE_CHECKSTOP_LSU_LOGIC		= 0x00000400,
+	CORE_CHECKSTOP_PC_LOGIC			= 0x00000800,
+	CORE_CHECKSTOP_PC_HYP_RESOURCE		= 0x00001000,
+	CORE_CHECKSTOP_PC_HANG_RECOV_FAILED	= 0x00002000,
+	CORE_CHECKSTOP_PC_AMBI_HANG_DETECTED	= 0x00004000,
+	CORE_CHECKSTOP_PC_DEBUG_TRIG_ERR_INJ	= 0x00008000,
+	CORE_CHECKSTOP_PC_SPRD_HYP_ERR_INJ	= 0x00010000,
+};
+
+enum OpalHMI_NestAccelXstopReason {
+	NX_CHECKSTOP_SHM_INVAL_STATE_ERR	= 0x00000001,
+	NX_CHECKSTOP_DMA_INVAL_STATE_ERR_1	= 0x00000002,
+	NX_CHECKSTOP_DMA_INVAL_STATE_ERR_2	= 0x00000004,
+	NX_CHECKSTOP_DMA_CH0_INVAL_STATE_ERR	= 0x00000008,
+	NX_CHECKSTOP_DMA_CH1_INVAL_STATE_ERR	= 0x00000010,
+	NX_CHECKSTOP_DMA_CH2_INVAL_STATE_ERR	= 0x00000020,
+	NX_CHECKSTOP_DMA_CH3_INVAL_STATE_ERR	= 0x00000040,
+	NX_CHECKSTOP_DMA_CH4_INVAL_STATE_ERR	= 0x00000080,
+	NX_CHECKSTOP_DMA_CH5_INVAL_STATE_ERR	= 0x00000100,
+	NX_CHECKSTOP_DMA_CH6_INVAL_STATE_ERR	= 0x00000200,
+	NX_CHECKSTOP_DMA_CH7_INVAL_STATE_ERR	= 0x00000400,
+	NX_CHECKSTOP_DMA_CRB_UE			= 0x00000800,
+	NX_CHECKSTOP_DMA_CRB_SUE		= 0x00001000,
+	NX_CHECKSTOP_PBI_ISN_UE			= 0x00002000,
+};
+
 struct OpalHMIEvent {
 	uint8_t		version;	/* 0x00 */
 	uint8_t		severity;	/* 0x01 */
@@ -477,6 +521,23 @@
 	__be64		hmer;
 	/* TFMR register. Valid only for TFAC and TFMR_PARITY error type. */
 	__be64		tfmr;
+
+	/* version 2 and later */
+	union {
+		/*
+		 * checkstop info (Core/NX).
+		 * Valid for OpalHMI_ERROR_MALFUNC_ALERT.
+		 */
+		struct {
+			uint8_t	xstop_type;	/* enum OpalHMI_XstopType */
+			uint8_t reserved_1[3];
+			__be32  xstop_reason;
+			union {
+				__be32 pir;	/* for CHECKSTOP_TYPE_CORE */
+				__be32 chip_id;	/* for CHECKSTOP_TYPE_NX */
+			} u;
+		} xstop_error;
+	} u;
 };
 
 enum {