target-s390x: add a tod2time function

Add a tod2time function similar to the time2tod one, instead of open
coding the conversion.
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAlexander Graf <agraf@suse.de>

target-s390x/cpu.h

@@ -995,6 +995,11 @@ static inline uint64_t time2tod(uint64_t ns) {
     return (ns << 9) / 125;
 }
 
+/* Converts s390's clock format to ns */
+static inline uint64_t tod2time(uint64_t t) {
+    return (t * 125) >> 9;
+}
+
 static inline void cpu_inject_ext(S390CPU *cpu, uint32_t code, uint32_t param,
                                   uint64_t param64)
 {

target-s390x/misc_helper.c

@@ -294,7 +294,7 @@ void HELPER(sckc)(CPUS390XState *env, uint64_t time)
     /* difference between now and then */
     time -= clock_value(env);
     /* nanoseconds */
-    time = (time * 125) >> 9;
+    time = tod2time(time);
 
     timer_mod(env->tod_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + time);
 }
@@ -314,7 +314,7 @@ void HELPER(spt)(CPUS390XState *env, uint64_t time)
     }
 
     /* nanoseconds */
-    time = (time * 125) >> 9;
+    time = tod2time(time);
 
     timer_mod(env->cpu_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + time);
 }