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 #include <linux/clocksource_ids.h>
   7
   8 /* Included from linux/ktime.h */
   9
  10 void timekeeping_init(void);
  11 extern int timekeeping_suspended;
  12
  13 /* Architecture timer tick functions: */
  14 extern void legacy_timer_tick(unsigned long ticks);
  15
  16 /*
  17  * Get and set timeofday
  18  */
  19 extern int do_settimeofday64(const struct timespec64 *ts);
  20 extern 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  */
  41 extern void ktime_get_raw_ts64(struct timespec64 *ts);
  42 extern void ktime_get_ts64(struct timespec64 *ts);
  43 extern void ktime_get_real_ts64(struct timespec64 *tv);
  44 extern void ktime_get_coarse_ts64(struct timespec64 *ts);
  45 extern void ktime_get_coarse_real_ts64(struct timespec64 *ts);
  46
  47 void getboottime64(struct timespec64 *ts);
  48
  49 /*
  50  * time64_t base interfaces
  51  */
  52 extern time64_t ktime_get_seconds(void);
  53 extern time64_t __ktime_get_real_seconds(void);
  54 extern time64_t ktime_get_real_seconds(void);
  55
  56 /*
  57  * ktime_t based interfaces
  58  */
  59
  60 enum tk_offsets {
  61         TK_OFFS_REAL,
  62         TK_OFFS_BOOT,
  63         TK_OFFS_TAI,
  64         TK_OFFS_MAX,
  65 };
  66
  67 extern ktime_t ktime_get(void);
  68 extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
  69 extern ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs);
  70 extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
  71 extern ktime_t ktime_get_raw(void);
  72 extern u32 ktime_get_resolution_ns(void);
  73
  74 /**
  75  * ktime_get_real - get the real (wall-) time in ktime_t format
  76  */
  77 static inline ktime_t ktime_get_real(void)
  78 {
  79         return ktime_get_with_offset(TK_OFFS_REAL);
  80 }
  81
  82 static 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  */
  93 static inline ktime_t ktime_get_boottime(void)
  94 {
  95         return ktime_get_with_offset(TK_OFFS_BOOT);
  96 }
  97
  98 static 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  */
 106 static inline ktime_t ktime_get_clocktai(void)
 107 {
 108         return ktime_get_with_offset(TK_OFFS_TAI);
 109 }
 110
 111 static inline ktime_t ktime_get_coarse_clocktai(void)
 112 {
 113         return ktime_get_coarse_with_offset(TK_OFFS_TAI);
 114 }
 115
 116 static inline ktime_t ktime_get_coarse(void)
 117 {
 118         struct timespec64 ts;
 119
 120         ktime_get_coarse_ts64(&ts);
 121         return timespec64_to_ktime(ts);
 122 }
 123
 124 static inline u64 ktime_get_coarse_ns(void)
 125 {
 126         return ktime_to_ns(ktime_get_coarse());
 127 }
 128
 129 static inline u64 ktime_get_coarse_real_ns(void)
 130 {
 131         return ktime_to_ns(ktime_get_coarse_real());
 132 }
 133
 134 static inline u64 ktime_get_coarse_boottime_ns(void)
 135 {
 136         return ktime_to_ns(ktime_get_coarse_boottime());
 137 }
 138
 139 static inline u64 ktime_get_coarse_clocktai_ns(void)
 140 {
 141         return ktime_to_ns(ktime_get_coarse_clocktai());
 142 }
 143
 144 /**
 145  * ktime_mono_to_real - Convert monotonic time to clock realtime
 146  */
 147 static inline ktime_t ktime_mono_to_real(ktime_t mono)
 148 {
 149         return ktime_mono_to_any(mono, TK_OFFS_REAL);
 150 }
 151
 152 static inline u64 ktime_get_ns(void)
 153 {
 154         return ktime_to_ns(ktime_get());
 155 }
 156
 157 static inline u64 ktime_get_real_ns(void)
 158 {
 159         return ktime_to_ns(ktime_get_real());
 160 }
 161
 162 static inline u64 ktime_get_boottime_ns(void)
 163 {
 164         return ktime_to_ns(ktime_get_boottime());
 165 }
 166
 167 static inline u64 ktime_get_clocktai_ns(void)
 168 {
 169         return ktime_to_ns(ktime_get_clocktai());
 170 }
 171
 172 static inline u64 ktime_get_raw_ns(void)
 173 {
 174         return ktime_to_ns(ktime_get_raw());
 175 }
 176
 177 extern u64 ktime_get_mono_fast_ns(void);
 178 extern u64 ktime_get_raw_fast_ns(void);
 179 extern u64 ktime_get_boot_fast_ns(void);
 180 extern u64 ktime_get_real_fast_ns(void);
 181
 182 /*
 183  * timespec64/time64_t interfaces utilizing the ktime based ones
 184  * for API completeness, these could be implemented more efficiently
 185  * if needed.
 186  */
 187 static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
 188 {
 189         *ts = ktime_to_timespec64(ktime_get_boottime());
 190 }
 191
 192 static inline void ktime_get_coarse_boottime_ts64(struct timespec64 *ts)
 193 {
 194         *ts = ktime_to_timespec64(ktime_get_coarse_boottime());
 195 }
 196
 197 static inline time64_t ktime_get_boottime_seconds(void)
 198 {
 199         return ktime_divns(ktime_get_coarse_boottime(), NSEC_PER_SEC);
 200 }
 201
 202 static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
 203 {
 204         *ts = ktime_to_timespec64(ktime_get_clocktai());
 205 }
 206
 207 static inline void ktime_get_coarse_clocktai_ts64(struct timespec64 *ts)
 208 {
 209         *ts = ktime_to_timespec64(ktime_get_coarse_clocktai());
 210 }
 211
 212 static inline time64_t ktime_get_clocktai_seconds(void)
 213 {
 214         return ktime_divns(ktime_get_coarse_clocktai(), NSEC_PER_SEC);
 215 }
 216
 217 /*
 218  * RTC specific
 219  */
 220 extern bool timekeeping_rtc_skipsuspend(void);
 221 extern bool timekeeping_rtc_skipresume(void);
 222
 223 extern void timekeeping_inject_sleeptime64(const struct timespec64 *delta);
 224
 225 /*
 226  * struct ktime_timestanps - Simultaneous mono/boot/real timestamps
 227  * @mono:       Monotonic timestamp
 228  * @boot:       Boottime timestamp
 229  * @real:       Realtime timestamp
 230  */
 231 struct ktime_timestamps {
 232         u64             mono;
 233         u64             boot;
 234         u64             real;
 235 };
 236
 237 /**
 238  * struct system_time_snapshot - simultaneous raw/real time capture with
 239  *                               counter value
 240  * @cycles:     Clocksource counter value to produce the system times
 241  * @real:       Realtime system time
 242  * @raw:        Monotonic raw system time
 243  * @clock_was_set_seq:  The sequence number of clock was set events
 244  * @cs_was_changed_seq: The sequence number of clocksource change events
 245  */
 246 struct system_time_snapshot {
 247         u64                     cycles;
 248         ktime_t                 real;
 249         ktime_t                 raw;
 250         enum clocksource_ids    cs_id;
 251         unsigned int            clock_was_set_seq;
 252         u8                      cs_was_changed_seq;
 253 };
 254
 255 /**
 256  * struct system_device_crosststamp - system/device cross-timestamp
 257  *                                    (synchronized capture)
 258  * @device:             Device time
 259  * @sys_realtime:       Realtime simultaneous with device time
 260  * @sys_monoraw:        Monotonic raw simultaneous with device time
 261  */
 262 struct system_device_crosststamp {
 263         ktime_t device;
 264         ktime_t sys_realtime;
 265         ktime_t sys_monoraw;
 266 };
 267
 268 /**
 269  * struct system_counterval_t - system counter value with the pointer to the
 270  *                              corresponding clocksource
 271  * @cycles:     System counter value
 272  * @cs:         Clocksource corresponding to system counter value. Used by
 273  *              timekeeping code to verify comparibility of two cycle values
 274  */
 275 struct system_counterval_t {
 276         u64                     cycles;
 277         struct clocksource      *cs;
 278 };
 279
 280 /*
 281  * Get cross timestamp between system clock and device clock
 282  */
 283 extern int get_device_system_crosststamp(
 284                         int (*get_time_fn)(ktime_t *device_time,
 285                                 struct system_counterval_t *system_counterval,
 286                                 void *ctx),
 287                         void *ctx,
 288                         struct system_time_snapshot *history,
 289                         struct system_device_crosststamp *xtstamp);
 290
 291 /*
 292  * Simultaneously snapshot realtime and monotonic raw clocks
 293  */
 294 extern void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot);
 295
 296 /* NMI safe mono/boot/realtime timestamps */
 297 extern void ktime_get_fast_timestamps(struct ktime_timestamps *snap);
 298
 299 /*
 300  * Persistent clock related interfaces
 301  */
 302 extern int persistent_clock_is_local;
 303
 304 extern void read_persistent_clock64(struct timespec64 *ts);
 305 void read_persistent_wall_and_boot_offset(struct timespec64 *wall_clock,
 306                                           struct timespec64 *boot_offset);
 307 #ifdef CONFIG_GENERIC_CMOS_UPDATE
 308 extern int update_persistent_clock64(struct timespec64 now);
 309 #endif
 310
 311 #endif