1 /* 2 * You SHOULD NOT be including this unless you're vsyscall 3 * handling code or timekeeping internal code! 4 */ 5 6 #ifndef _LINUX_TIMEKEEPER_INTERNAL_H 7 #define _LINUX_TIMEKEEPER_INTERNAL_H 8 9 #include <linux/clocksource.h> 10 #include <linux/jiffies.h> 11 #include <linux/time.h> 12 13 /** 14 * struct tk_read_base - base structure for timekeeping readout 15 * @clock: Current clocksource used for timekeeping. 16 * @read: Read function of @clock 17 * @mask: Bitmask for two's complement subtraction of non 64bit clocks 18 * @cycle_last: @clock cycle value at last update 19 * @mult: (NTP adjusted) multiplier for scaled math conversion 20 * @shift: Shift value for scaled math conversion 21 * @xtime_nsec: Shifted (fractional) nano seconds offset for readout 22 * @base: ktime_t (nanoseconds) base time for readout 23 * 24 * This struct has size 56 byte on 64 bit. Together with a seqcount it 25 * occupies a single 64byte cache line. 26 * 27 * The struct is separate from struct timekeeper as it is also used 28 * for a fast NMI safe accessors. 29 */ 30 struct tk_read_base { 31 struct clocksource *clock; 32 cycle_t (*read)(struct clocksource *cs); 33 cycle_t mask; 34 cycle_t cycle_last; 35 u32 mult; 36 u32 shift; 37 u64 xtime_nsec; 38 ktime_t base; 39 }; 40 41 /** 42 * struct timekeeper - Structure holding internal timekeeping values. 43 * @tkr_mono: The readout base structure for CLOCK_MONOTONIC 44 * @tkr_raw: The readout base structure for CLOCK_MONOTONIC_RAW 45 * @xtime_sec: Current CLOCK_REALTIME time in seconds 46 * @ktime_sec: Current CLOCK_MONOTONIC time in seconds 47 * @wall_to_monotonic: CLOCK_REALTIME to CLOCK_MONOTONIC offset 48 * @offs_real: Offset clock monotonic -> clock realtime 49 * @offs_boot: Offset clock monotonic -> clock boottime 50 * @offs_tai: Offset clock monotonic -> clock tai 51 * @tai_offset: The current UTC to TAI offset in seconds 52 * @clock_was_set_seq: The sequence number of clock was set events 53 * @raw_time: Monotonic raw base time in timespec64 format 54 * @cycle_interval: Number of clock cycles in one NTP interval 55 * @xtime_interval: Number of clock shifted nano seconds in one NTP 56 * interval. 57 * @xtime_remainder: Shifted nano seconds left over when rounding 58 * @cycle_interval 59 * @raw_interval: Raw nano seconds accumulated per NTP interval. 60 * @ntp_error: Difference between accumulated time and NTP time in ntp 61 * shifted nano seconds. 62 * @ntp_error_shift: Shift conversion between clock shifted nano seconds and 63 * ntp shifted nano seconds. 64 * 65 * Note: For timespec(64) based interfaces wall_to_monotonic is what 66 * we need to add to xtime (or xtime corrected for sub jiffie times) 67 * to get to monotonic time. Monotonic is pegged at zero at system 68 * boot time, so wall_to_monotonic will be negative, however, we will 69 * ALWAYS keep the tv_nsec part positive so we can use the usual 70 * normalization. 71 * 72 * wall_to_monotonic is moved after resume from suspend for the 73 * monotonic time not to jump. We need to add total_sleep_time to 74 * wall_to_monotonic to get the real boot based time offset. 75 * 76 * wall_to_monotonic is no longer the boot time, getboottime must be 77 * used instead. 78 */ 79 struct timekeeper { 80 struct tk_read_base tkr_mono; 81 struct tk_read_base tkr_raw; 82 u64 xtime_sec; 83 unsigned long ktime_sec; 84 struct timespec64 wall_to_monotonic; 85 ktime_t offs_real; 86 ktime_t offs_boot; 87 ktime_t offs_tai; 88 s32 tai_offset; 89 unsigned int clock_was_set_seq; 90 struct timespec64 raw_time; 91 92 /* The following members are for timekeeping internal use */ 93 cycle_t cycle_interval; 94 u64 xtime_interval; 95 s64 xtime_remainder; 96 u32 raw_interval; 97 /* The ntp_tick_length() value currently being used. 98 * This cached copy ensures we consistently apply the tick 99 * length for an entire tick, as ntp_tick_length may change 100 * mid-tick, and we don't want to apply that new value to 101 * the tick in progress. 102 */ 103 u64 ntp_tick; 104 /* Difference between accumulated time and NTP time in ntp 105 * shifted nano seconds. */ 106 s64 ntp_error; 107 u32 ntp_error_shift; 108 u32 ntp_err_mult; 109 }; 110 111 #ifdef CONFIG_GENERIC_TIME_VSYSCALL 112 113 extern void update_vsyscall(struct timekeeper *tk); 114 extern void update_vsyscall_tz(void); 115 116 #elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD) 117 118 extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm, 119 struct clocksource *c, u32 mult, 120 cycle_t cycle_last); 121 extern void update_vsyscall_tz(void); 122 123 #else 124 125 static inline void update_vsyscall(struct timekeeper *tk) 126 { 127 } 128 static inline void update_vsyscall_tz(void) 129 { 130 } 131 #endif 132 133 #endif /* _LINUX_TIMEKEEPER_INTERNAL_H */ 134