LXR linux/include/linux/timekeeping.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_TIMEKEEPING_H
   3#define _LINUX_TIMEKEEPING_H
   4
   5#include <linux/errno.h>
   6
   7/* Included from linux/ktime.h */
   8
   9void timekeeping_init(void);
  10extern int timekeeping_suspended;
  11
  12/* Architecture timer tick functions: */
  13extern void update_process_times(int user);
  14extern void xtime_update(unsigned long ticks);
  15
  16/*
  17 * Get and set timeofday
  18 */
  19extern int do_settimeofday64(const struct timespec64 *ts);
  20extern int do_sys_settimeofday64(const struct timespec64 *tv,
  21                                 const struct timezone *tz);
  22
  23/*
  24 * ktime_get() family: read the current time in a multitude of ways,
  25 *
  26 * The default time reference is CLOCK_MONOTONIC, starting at
  27 * boot time but not counting the time spent in suspend.
  28 * For other references, use the functions with "real", "clocktai",
  29 * "boottime" and "raw" suffixes.
  30 *
  31 * To get the time in a different format, use the ones wit
  32 * "ns", "ts64" and "seconds" suffix.
  33 *
  34 * See Documentation/core-api/timekeeping.rst for more details.
  35 */
  36
  37
  38/*
  39 * timespec64 based interfaces
  40 */
  41extern void ktime_get_raw_ts64(struct timespec64 *ts);
  42extern void ktime_get_ts64(struct timespec64 *ts);
  43extern void ktime_get_real_ts64(struct timespec64 *tv);
  44extern void ktime_get_coarse_ts64(struct timespec64 *ts);
  45extern void ktime_get_coarse_real_ts64(struct timespec64 *ts);
  46
  47void getboottime64(struct timespec64 *ts);
  48
  49/*
  50 * time64_t base interfaces
  51 */
  52extern time64_t ktime_get_seconds(void);
  53extern time64_t __ktime_get_real_seconds(void);
  54extern time64_t ktime_get_real_seconds(void);
  55
  56/*
  57 * ktime_t based interfaces
  58 */
  59
  60enum tk_offsets {
  61        TK_OFFS_REAL,
  62        TK_OFFS_BOOT,
  63        TK_OFFS_TAI,
  64        TK_OFFS_MAX,
  65};
  66
  67extern ktime_t ktime_get(void);
  68extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
  69extern ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs);
  70extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
  71extern ktime_t ktime_get_raw(void);
  72extern u32 ktime_get_resolution_ns(void);
  73
  74/**
  75 * ktime_get_real - get the real (wall-) time in ktime_t format
  76 */
  77static inline ktime_t ktime_get_real(void)
  78{
  79        return ktime_get_with_offset(TK_OFFS_REAL);
  80}
  81
  82static inline ktime_t ktime_get_coarse_real(void)
  83{
  84        return ktime_get_coarse_with_offset(TK_OFFS_REAL);
  85}
  86
  87/**
  88 * ktime_get_boottime - Returns monotonic time since boot in ktime_t format
  89 *
  90 * This is similar to CLOCK_MONTONIC/ktime_get, but also includes the
  91 * time spent in suspend.
  92 */
  93static inline ktime_t ktime_get_boottime(void)
  94{
  95        return ktime_get_with_offset(TK_OFFS_BOOT);
  96}
  97
  98static inline ktime_t ktime_get_coarse_boottime(void)
  99{
 100        return ktime_get_coarse_with_offset(TK_OFFS_BOOT);
 101}
 102
 103/**
 104 * ktime_get_clocktai - Returns the TAI time of day in ktime_t format
 105 */
 106static inline ktime_t ktime_get_clocktai(void)
 107{
 108        return ktime_get_with_offset(TK_OFFS_TAI);
 109}
 110
 111static inline ktime_t ktime_get_coarse_clocktai(void)
 112{
 113        return ktime_get_coarse_with_offset(TK_OFFS_TAI);
 114}
 115
 116/**
 117 * ktime_mono_to_real - Convert monotonic time to clock realtime
 118 */
 119static inline ktime_t ktime_mono_to_real(ktime_t mono)
 120{
 121        return ktime_mono_to_any(mono, TK_OFFS_REAL);
 122}
 123
 124static inline u64 ktime_get_ns(void)
 125{
 126        return ktime_to_ns(ktime_get());
 127}
 128
 129static inline u64 ktime_get_real_ns(void)
 130{
 131        return ktime_to_ns(ktime_get_real());
 132}
 133
 134static inline u64 ktime_get_boot_ns(void)
 135{
 136        return ktime_to_ns(ktime_get_boottime());
 137}
 138
 139static inline u64 ktime_get_tai_ns(void)
 140{
 141        return ktime_to_ns(ktime_get_clocktai());
 142}
 143
 144static inline u64 ktime_get_raw_ns(void)
 145{
 146        return ktime_to_ns(ktime_get_raw());
 147}
 148
 149extern u64 ktime_get_mono_fast_ns(void);
 150extern u64 ktime_get_raw_fast_ns(void);
 151extern u64 ktime_get_boot_fast_ns(void);
 152extern u64 ktime_get_real_fast_ns(void);
 153
 154/*
 155 * timespec64/time64_t interfaces utilizing the ktime based ones
 156 * for API completeness, these could be implemented more efficiently
 157 * if needed.
 158 */
 159static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
 160{
 161        *ts = ktime_to_timespec64(ktime_get_boottime());
 162}
 163
 164static inline void ktime_get_coarse_boottime_ts64(struct timespec64 *ts)
 165{
 166        *ts = ktime_to_timespec64(ktime_get_coarse_boottime());
 167}
 168
 169static inline time64_t ktime_get_boottime_seconds(void)
 170{
 171        return ktime_divns(ktime_get_coarse_boottime(), NSEC_PER_SEC);
 172}
 173
 174static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
 175{
 176        *ts = ktime_to_timespec64(ktime_get_clocktai());
 177}
 178
 179static inline void ktime_get_coarse_clocktai_ts64(struct timespec64 *ts)
 180{
 181        *ts = ktime_to_timespec64(ktime_get_coarse_clocktai());
 182}
 183
 184static inline time64_t ktime_get_clocktai_seconds(void)
 185{
 186        return ktime_divns(ktime_get_coarse_clocktai(), NSEC_PER_SEC);
 187}
 188
 189/*
 190 * RTC specific
 191 */
 192extern bool timekeeping_rtc_skipsuspend(void);
 193extern bool timekeeping_rtc_skipresume(void);
 194
 195extern void timekeeping_inject_sleeptime64(const struct timespec64 *delta);
 196
 197/*
 198 * struct system_time_snapshot - simultaneous raw/real time capture with
 199 *      counter value
 200 * @cycles:     Clocksource counter value to produce the system times
 201 * @real:       Realtime system time
 202 * @raw:        Monotonic raw system time
 203 * @clock_was_set_seq:  The sequence number of clock was set events
 204 * @cs_was_changed_seq: The sequence number of clocksource change events
 205 */
 206struct system_time_snapshot {
 207        u64             cycles;
 208        ktime_t         real;
 209        ktime_t         raw;
 210        unsigned int    clock_was_set_seq;
 211        u8              cs_was_changed_seq;
 212};
 213
 214/*
 215 * struct system_device_crosststamp - system/device cross-timestamp
 216 *      (syncronized capture)
 217 * @device:             Device time
 218 * @sys_realtime:       Realtime simultaneous with device time
 219 * @sys_monoraw:        Monotonic raw simultaneous with device time
 220 */
 221struct system_device_crosststamp {
 222        ktime_t device;
 223        ktime_t sys_realtime;
 224        ktime_t sys_monoraw;
 225};
 226
 227/*
 228 * struct system_counterval_t - system counter value with the pointer to the
 229 *      corresponding clocksource
 230 * @cycles:     System counter value
 231 * @cs:         Clocksource corresponding to system counter value. Used by
 232 *      timekeeping code to verify comparibility of two cycle values
 233 */
 234struct system_counterval_t {
 235        u64                     cycles;
 236        struct clocksource      *cs;
 237};
 238
 239/*
 240 * Get cross timestamp between system clock and device clock
 241 */
 242extern int get_device_system_crosststamp(
 243                        int (*get_time_fn)(ktime_t *device_time,
 244                                struct system_counterval_t *system_counterval,
 245                                void *ctx),
 246                        void *ctx,
 247                        struct system_time_snapshot *history,
 248                        struct system_device_crosststamp *xtstamp);
 249
 250/*
 251 * Simultaneously snapshot realtime and monotonic raw clocks
 252 */
 253extern void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot);
 254
 255/*
 256 * Persistent clock related interfaces
 257 */
 258extern int persistent_clock_is_local;
 259
 260extern void read_persistent_clock64(struct timespec64 *ts);
 261void read_persistent_wall_and_boot_offset(struct timespec64 *wall_clock,
 262                                          struct timespec64 *boot_offset);
 263extern int update_persistent_clock64(struct timespec64 now);
 264
 265#endif
 266