xref: /openbmc/qemu/target/s390x/tcg/s390-tod.h (revision ffe98631)
1 /*
2  * TOD (Time Of Day) clock
3  *
4  * Copyright 2018 Red Hat, Inc.
5  * Author(s): David Hildenbrand <david@redhat.com>
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2 or later.
8  * See the COPYING file in the top-level directory.
9  */
10 
11 #ifndef TARGET_S390_TOD_H
12 #define TARGET_S390_TOD_H
13 
14 /* The value of the TOD clock for 1.1.1970. */
15 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
16 
17 /* Converts ns to s390's clock format */
18 static inline uint64_t time2tod(uint64_t ns)
19 {
20     return (ns << 9) / 125 + (((ns & 0xff80000000000000ull) / 125) << 9);
21 }
22 
23 /* Converts s390's clock format to ns */
24 static inline uint64_t tod2time(uint64_t t)
25 {
26     return ((t >> 9) * 125) + (((t & 0x1ff) * 125) >> 9);
27 }
28 
29 #endif
30