include/hw/s390x/tod.h

   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 HW_S390_TOD_H
  12 #define HW_S390_TOD_H
  13
  14 #include "hw/qdev.h"
  15
  16 typedef struct S390TOD {
  17     uint8_t high;
  18     uint64_t low;
  19 } S390TOD;
  20
  21 #define TYPE_S390_TOD "s390-tod"
  22 #define S390_TOD(obj) OBJECT_CHECK(S390TODState, (obj), TYPE_S390_TOD)
  23 #define S390_TOD_CLASS(oc) OBJECT_CLASS_CHECK(S390TODClass, (oc), \
  24                                               TYPE_S390_TOD)
  25 #define S390_TOD_GET_CLASS(obj) OBJECT_GET_CLASS(S390TODClass, (obj), \
  26                                                  TYPE_S390_TOD)
  27 #define TYPE_KVM_S390_TOD TYPE_S390_TOD "-kvm"
  28 #define TYPE_QEMU_S390_TOD TYPE_S390_TOD "-qemu"
  29
  30 typedef struct S390TODState {
  31     /* private */
  32     DeviceState parent_obj;
  33
  34     /*
  35      * Used by TCG to remember the time base. Used by KVM to backup the TOD
  36      * while the TOD is stopped.
  37      */
  38     S390TOD base;
  39     /* Used by KVM to remember if the TOD is stopped and base is valid. */
  40     bool stopped;
  41 } S390TODState;
  42
  43 typedef struct S390TODClass {
  44     /* private */
  45     DeviceClass parent_class;
  46     void (*parent_realize)(DeviceState *dev, Error **errp);
  47
  48     /* public */
  49     void (*get)(const S390TODState *td, S390TOD *tod, Error **errp);
  50     void (*set)(S390TODState *td, const S390TOD *tod, Error **errp);
  51 } S390TODClass;
  52
  53 /* The value of the TOD clock for 1.1.1970. */
  54 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
  55
  56 /* Converts ns to s390's clock format */
  57 static inline uint64_t time2tod(uint64_t ns)
  58 {
  59     return (ns << 9) / 125 + (((ns & 0xff80000000000000ull) / 125) << 9);
  60 }
  61
  62 /* Converts s390's clock format to ns */
  63 static inline uint64_t tod2time(uint64_t t)
  64 {
  65     return ((t >> 9) * 125) + (((t & 0x1ff) * 125) >> 9);
  66 }
  67
  68 void s390_init_tod(void);
  69 S390TODState *s390_get_todstate(void);
  70
  71 #endif