diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index cf6e1ca..1293640 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -10,20 +10,81 @@
 #ifndef _ASM_S390X_ARCH_DEF_H_
 #define _ASM_S390X_ARCH_DEF_H_
 
-struct psw {
-	uint64_t	mask;
-	uint64_t	addr;
-};
-
 #define PSW_MASK_EXT			0x0100000000000000UL
 #define PSW_MASK_DAT			0x0400000000000000UL
 #define PSW_MASK_PSTATE			0x0001000000000000UL
+#define PSW_MASK_IO			0x0200000000000000
+#define PSW_MASK_EA			0x0000000100000000
+#define PSW_MASK_BA			0x0000000080000000
+
+#define PSW_EXCEPTION_MASK (PSW_MASK_EA|PSW_MASK_BA)
 
 #define CR0_EXTM_SCLP			0X0000000000000200UL
 #define CR0_EXTM_EXTC			0X0000000000002000UL
 #define CR0_EXTM_EMGC			0X0000000000004000UL
 #define CR0_EXTM_MASK			0X0000000000006200UL
 
+#define PGM_INT_CODE_OPERATION			0x01
+#define PGM_INT_CODE_PRIVILEGED_OPERATION	0x02
+#define PGM_INT_CODE_EXECUTE			0x03
+#define PGM_INT_CODE_PROTECTION			0x04
+#define PGM_INT_CODE_ADDRESSING			0x05
+#define PGM_INT_CODE_SPECIFICATION		0x06
+#define PGM_INT_CODE_DATA			0x07
+#define PGM_INT_CODE_FIXED_POINT_OVERFLOW	0x08
+#define PGM_INT_CODE_FIXED_POINT_DIVIDE		0x09
+#define PGM_INT_CODE_DECIMAL_OVERFLOW		0x0a
+#define PGM_INT_CODE_DECIMAL_DIVIDE		0x0b
+#define PGM_INT_CODE_HFP_EXPONENT_OVERFLOW	0x0c
+#define PGM_INT_CODE_HFP_EXPONENT_UNDERFLOW	0x0d
+#define PGM_INT_CODE_HFP_SIGNIFICANCE		0x0e
+#define PGM_INT_CODE_HFP_DIVIDE			0x0f
+#define PGM_INT_CODE_SEGMENT_TRANSLATION	0x10
+#define PGM_INT_CODE_PAGE_TRANSLATION		0x11
+#define PGM_INT_CODE_TRANSLATION_SPEC		0x12
+#define PGM_INT_CODE_SPECIAL_OPERATION		0x13
+#define PGM_INT_CODE_OPERAND			0x15
+#define PGM_INT_CODE_TRACE_TABLE		0x16
+#define PGM_INT_CODE_VECTOR_PROCESSING		0x1b
+#define PGM_INT_CODE_SPACE_SWITCH_EVENT		0x1c
+#define PGM_INT_CODE_HFP_SQUARE_ROOT		0x1d
+#define PGM_INT_CODE_PC_TRANSLATION_SPEC	0x1f
+#define PGM_INT_CODE_AFX_TRANSLATION		0x20
+#define PGM_INT_CODE_ASX_TRANSLATION		0x21
+#define PGM_INT_CODE_LX_TRANSLATION		0x22
+#define PGM_INT_CODE_EX_TRANSLATION		0x23
+#define PGM_INT_CODE_PRIMARY_AUTHORITY		0x24
+#define PGM_INT_CODE_SECONDARY_AUTHORITY	0x25
+#define PGM_INT_CODE_LFX_TRANSLATION		0x26
+#define PGM_INT_CODE_LSX_TRANSLATION		0x27
+#define PGM_INT_CODE_ALET_SPECIFICATION		0x28
+#define PGM_INT_CODE_ALEN_TRANSLATION		0x29
+#define PGM_INT_CODE_ALE_SEQUENCE		0x2a
+#define PGM_INT_CODE_ASTE_VALIDITY		0x2b
+#define PGM_INT_CODE_ASTE_SEQUENCE		0x2c
+#define PGM_INT_CODE_EXTENDED_AUTHORITY		0x2d
+#define PGM_INT_CODE_LSTE_SEQUENCE		0x2e
+#define PGM_INT_CODE_ASTE_INSTANCE		0x2f
+#define PGM_INT_CODE_STACK_FULL			0x30
+#define PGM_INT_CODE_STACK_EMPTY		0x31
+#define PGM_INT_CODE_STACK_SPECIFICATION	0x32
+#define PGM_INT_CODE_STACK_TYPE			0x33
+#define PGM_INT_CODE_STACK_OPERATION		0x34
+#define PGM_INT_CODE_ASCE_TYPE			0x38
+#define PGM_INT_CODE_REGION_FIRST_TRANS		0x39
+#define PGM_INT_CODE_REGION_SECOND_TRANS	0x3a
+#define PGM_INT_CODE_REGION_THIRD_TRANS		0x3b
+#define PGM_INT_CODE_MONITOR_EVENT		0x40
+#define PGM_INT_CODE_PER			0x80
+#define PGM_INT_CODE_CRYPTO_OPERATION		0x119
+#define PGM_INT_CODE_TX_ABORTED_EVENT		0x200
+
+#ifndef __ASSEMBLER__
+struct psw {
+	uint64_t	mask;
+	uint64_t	addr;
+};
+
 struct lowcore {
 	uint8_t		pad_0x0000[0x0080 - 0x0000];	/* 0x0000 */
 	uint32_t	ext_int_param;			/* 0x0080 */
@@ -101,61 +162,6 @@ struct lowcore {
 } __attribute__ ((__packed__));
 _Static_assert(sizeof(struct lowcore) == 0x1900, "Lowcore size");
 
-#define PGM_INT_CODE_OPERATION			0x01
-#define PGM_INT_CODE_PRIVILEGED_OPERATION	0x02
-#define PGM_INT_CODE_EXECUTE			0x03
-#define PGM_INT_CODE_PROTECTION			0x04
-#define PGM_INT_CODE_ADDRESSING			0x05
-#define PGM_INT_CODE_SPECIFICATION		0x06
-#define PGM_INT_CODE_DATA			0x07
-#define PGM_INT_CODE_FIXED_POINT_OVERFLOW	0x08
-#define PGM_INT_CODE_FIXED_POINT_DIVIDE		0x09
-#define PGM_INT_CODE_DECIMAL_OVERFLOW		0x0a
-#define PGM_INT_CODE_DECIMAL_DIVIDE		0x0b
-#define PGM_INT_CODE_HFP_EXPONENT_OVERFLOW	0x0c
-#define PGM_INT_CODE_HFP_EXPONENT_UNDERFLOW	0x0d
-#define PGM_INT_CODE_HFP_SIGNIFICANCE		0x0e
-#define PGM_INT_CODE_HFP_DIVIDE			0x0f
-#define PGM_INT_CODE_SEGMENT_TRANSLATION	0x10
-#define PGM_INT_CODE_PAGE_TRANSLATION		0x11
-#define PGM_INT_CODE_TRANSLATION_SPEC		0x12
-#define PGM_INT_CODE_SPECIAL_OPERATION		0x13
-#define PGM_INT_CODE_OPERAND			0x15
-#define PGM_INT_CODE_TRACE_TABLE		0x16
-#define PGM_INT_CODE_VECTOR_PROCESSING		0x1b
-#define PGM_INT_CODE_SPACE_SWITCH_EVENT		0x1c
-#define PGM_INT_CODE_HFP_SQUARE_ROOT		0x1d
-#define PGM_INT_CODE_PC_TRANSLATION_SPEC	0x1f
-#define PGM_INT_CODE_AFX_TRANSLATION		0x20
-#define PGM_INT_CODE_ASX_TRANSLATION		0x21
-#define PGM_INT_CODE_LX_TRANSLATION		0x22
-#define PGM_INT_CODE_EX_TRANSLATION		0x23
-#define PGM_INT_CODE_PRIMARY_AUTHORITY		0x24
-#define PGM_INT_CODE_SECONDARY_AUTHORITY	0x25
-#define PGM_INT_CODE_LFX_TRANSLATION		0x26
-#define PGM_INT_CODE_LSX_TRANSLATION		0x27
-#define PGM_INT_CODE_ALET_SPECIFICATION		0x28
-#define PGM_INT_CODE_ALEN_TRANSLATION		0x29
-#define PGM_INT_CODE_ALE_SEQUENCE		0x2a
-#define PGM_INT_CODE_ASTE_VALIDITY		0x2b
-#define PGM_INT_CODE_ASTE_SEQUENCE		0x2c
-#define PGM_INT_CODE_EXTENDED_AUTHORITY		0x2d
-#define PGM_INT_CODE_LSTE_SEQUENCE		0x2e
-#define PGM_INT_CODE_ASTE_INSTANCE		0x2f
-#define PGM_INT_CODE_STACK_FULL			0x30
-#define PGM_INT_CODE_STACK_EMPTY		0x31
-#define PGM_INT_CODE_STACK_SPECIFICATION	0x32
-#define PGM_INT_CODE_STACK_TYPE			0x33
-#define PGM_INT_CODE_STACK_OPERATION		0x34
-#define PGM_INT_CODE_ASCE_TYPE			0x38
-#define PGM_INT_CODE_REGION_FIRST_TRANS		0x39
-#define PGM_INT_CODE_REGION_SECOND_TRANS	0x3a
-#define PGM_INT_CODE_REGION_THIRD_TRANS		0x3b
-#define PGM_INT_CODE_MONITOR_EVENT		0x40
-#define PGM_INT_CODE_PER			0x80
-#define PGM_INT_CODE_CRYPTO_OPERATION		0x119
-#define PGM_INT_CODE_TX_ABORTED_EVENT		0x200
-
 struct cpuid {
 	uint64_t version : 8;
 	uint64_t id : 24;
@@ -271,4 +277,5 @@ static inline int stsi(void *addr, int fc, int sel1, int sel2)
 	return cc;
 }
 
+#endif /* __ASSEMBLER__ */
 #endif
diff --git a/s390x/cstart64.S b/s390x/cstart64.S
index ff05f9b..f292ed6 100644
--- a/s390x/cstart64.S
+++ b/s390x/cstart64.S
@@ -12,6 +12,7 @@
  */
 #include <asm/asm-offsets.h>
 #include <asm/sigp.h>
+#include <asm/arch_def.h>
 
 .section .init
 
@@ -216,17 +217,17 @@ svc_int:
 reset_psw:
 	.quad	0x0008000180000000
 initial_psw:
-	.quad	0x0000000180000000, clear_bss_start
+	.quad	PSW_EXCEPTION_MASK, clear_bss_start
 pgm_int_psw:
-	.quad	0x0000000180000000, pgm_int
+	.quad	PSW_EXCEPTION_MASK, pgm_int
 ext_int_psw:
-	.quad	0x0000000180000000, ext_int
+	.quad	PSW_EXCEPTION_MASK, ext_int
 mcck_int_psw:
-	.quad	0x0000000180000000, mcck_int
+	.quad	PSW_EXCEPTION_MASK, mcck_int
 io_int_psw:
-	.quad	0x0000000180000000, io_int
+	.quad	PSW_EXCEPTION_MASK, io_int
 svc_int_psw:
-	.quad	0x0000000180000000, svc_int
+	.quad	PSW_EXCEPTION_MASK, svc_int
 initial_cr0:
 	/* enable AFP-register control, so FP regs (+BFP instr) can be used */
 	.quad	0x0000000000040000
