diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 464db3e..4ec3380 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -390,46 +390,6 @@ static inline void cpu_get_tb_cpu_state(CPUS390XState* env, target_ulong *pc,
 #define PER_CODE_EVENT_STORE_REAL      0x0800
 #define PER_CODE_EVENT_NULLIFICATION   0x0100
 
-S390CPU *cpu_s390x_init(const char *cpu_model);
-S390CPU *s390x_new_cpu(const char *cpu_model, int64_t id, Error **errp);
-
-/* you can call this signal handler from your SIGBUS and SIGSEGV
-   signal handlers to inform the virtual CPU of exceptions. non zero
-   is returned if the signal was handled by the virtual CPU.  */
-int cpu_s390x_signal_handler(int host_signum, void *pinfo,
-                           void *puc);
-
-
-#ifndef CONFIG_USER_ONLY
-
-void s390_enable_css_support(S390CPU *cpu);
-int s390_virtio_hypercall(CPUS390XState *env);
-
-int s390_get_clock(uint8_t *tod_high, uint64_t *tod_low);
-int s390_set_clock(uint8_t *tod_high, uint64_t *tod_low);
-
-S390CPU *s390_cpu_addr2state(uint16_t cpu_addr);
-unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu);
-
-/* service interrupts are floating therefore we must not pass an cpustate */
-void s390_sclp_extint(uint32_t parm);
-
-#else
-static inline unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu)
-{
-    return 0;
-}
-#endif
-
-extern void subsystem_reset(void);
-
-#define cpu_init(model) CPU(cpu_s390x_init(model))
-#define cpu_signal_handler cpu_s390x_signal_handler
-
-void s390_cpu_list(FILE *f, fprintf_function cpu_fprintf);
-#define cpu_list s390_cpu_list
-const char *s390_default_cpu_model_name(void);
-
 #define EXCP_EXT 1 /* external interrupt */
 #define EXCP_SVC 2 /* supervisor call (syscall) */
 #define EXCP_PGM 3 /* program interruption */
@@ -649,39 +609,10 @@ struct sysib_322 {
 /* SIGP order code mask corresponding to bit positions 56-63 */
 #define SIGP_ORDER_MASK 0x000000ff
 
-int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code);
-
-int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, uint8_t ar, void *hostbuf,
-                         int len, bool is_write);
-
-#define s390_cpu_virt_mem_read(cpu, laddr, ar, dest, len)    \
-        s390_cpu_virt_mem_rw(cpu, laddr, ar, dest, len, false)
-#define s390_cpu_virt_mem_write(cpu, laddr, ar, dest, len)       \
-        s390_cpu_virt_mem_rw(cpu, laddr, ar, dest, len, true)
-#define s390_cpu_virt_mem_check_write(cpu, laddr, ar, len)   \
-        s390_cpu_virt_mem_rw(cpu, laddr, ar, NULL, len, true)
-
 /* from s390-virtio-ccw */
 #define MEM_SECTION_SIZE             0x10000000UL
 #define MAX_AVAIL_SLOTS              32
 
-/* automatically detect the instruction length */
-#define ILEN_AUTO                   0xff
-void program_interrupt(CPUS390XState *env, uint32_t code, int ilen);
-
-
-int s390_set_memory_limit(uint64_t new_limit, uint64_t *hw_limit);
-void s390_cmma_reset(void);
-int s390_cpu_restart(S390CPU *cpu);
-int s390_get_memslot_count(void);
-void s390_io_interrupt(uint16_t subchannel_id, uint16_t subchannel_nr,
-                       uint32_t io_int_parm, uint32_t io_int_word);
-void s390_crw_mchk(void);
-int s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch_id,
-                                int vq, bool assign);
-void s390_crypto_reset(void);
-bool s390_get_squash_mcss(void);
-
 /* machine check interruption code */
 
 /* subclasses */
@@ -727,4 +658,72 @@ bool s390_get_squash_mcss(void);
 #define MCIC_VB_CT 0x0000000000020000ULL
 #define MCIC_VB_CC 0x0000000000010000ULL
 
+
+/* cpu.c */
+int s390_get_clock(uint8_t *tod_high, uint64_t *tod_low);
+int s390_set_clock(uint8_t *tod_high, uint64_t *tod_low);
+void s390_crypto_reset(void);
+bool s390_get_squash_mcss(void);
+int s390_get_memslot_count(void);
+int s390_set_memory_limit(uint64_t new_limit, uint64_t *hw_limit);
+void s390_cmma_reset(void);
+int s390_cpu_restart(S390CPU *cpu);
+void s390_enable_css_support(S390CPU *cpu);
+int s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch_id,
+                                int vq, bool assign);
+#ifndef CONFIG_USER_ONLY
+unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu);
+#else
+static inline unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu)
+{
+    return 0;
+}
+#endif /* CONFIG_USER_ONLY */
+
+
+/* cpu_models.c */
+void s390_cpu_list(FILE *f, fprintf_function cpu_fprintf);
+#define cpu_list s390_cpu_list
+const char *s390_default_cpu_model_name(void);
+
+
+/* helper.c */
+S390CPU *cpu_s390x_init(const char *cpu_model);
+#define cpu_init(model) CPU(cpu_s390x_init(model))
+S390CPU *s390x_new_cpu(const char *cpu_model, int64_t id, Error **errp);
+/* you can call this signal handler from your SIGBUS and SIGSEGV
+   signal handlers to inform the virtual CPU of exceptions. non zero
+   is returned if the signal was handled by the virtual CPU.  */
+int cpu_s390x_signal_handler(int host_signum, void *pinfo, void *puc);
+#define cpu_signal_handler cpu_s390x_signal_handler
+
+
+/* interrupt.c */
+void s390_crw_mchk(void);
+void s390_io_interrupt(uint16_t subchannel_id, uint16_t subchannel_nr,
+                       uint32_t io_int_parm, uint32_t io_int_word);
+/* automatically detect the instruction length */
+#define ILEN_AUTO                   0xff
+void program_interrupt(CPUS390XState *env, uint32_t code, int ilen);
+/* service interrupts are floating therefore we must not pass an cpustate */
+void s390_sclp_extint(uint32_t parm);
+
+
+/* mmu_helper.c */
+int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, uint8_t ar, void *hostbuf,
+                         int len, bool is_write);
+#define s390_cpu_virt_mem_read(cpu, laddr, ar, dest, len)    \
+        s390_cpu_virt_mem_rw(cpu, laddr, ar, dest, len, false)
+#define s390_cpu_virt_mem_write(cpu, laddr, ar, dest, len)       \
+        s390_cpu_virt_mem_rw(cpu, laddr, ar, dest, len, true)
+#define s390_cpu_virt_mem_check_write(cpu, laddr, ar, len)   \
+        s390_cpu_virt_mem_rw(cpu, laddr, ar, NULL, len, true)
+
+
+/* outside of target/s390x/ */
+S390CPU *s390_cpu_addr2state(uint16_t cpu_addr);
+extern void subsystem_reset(void);
+int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code);
+int s390_virtio_hypercall(CPUS390XState *env);
+
 #endif
