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 u64 mask; 33 u64 cycle_last; 34 u32 mult; 35 u32 shift; 36 u64 xtime_nsec; 37 ktime_t base; 38 }; 39 40 /** 41 * struct timekeeper - Structure holding internal timekeeping values. 42 * @tkr_mono: The readout base structure for CLOCK_MONOTONIC 43 * @tkr_raw: The readout base structure for CLOCK_MONOTONIC_RAW 44 * @xtime_sec: Current CLOCK_REALTIME time in seconds 45 * @ktime_sec: Current CLOCK_MONOTONIC time in seconds 46 * @wall_to_monotonic: CLOCK_REALTIME to CLOCK_MONOTONIC offset 47 * @offs_real: Offset clock monotonic -> clock realtime 48 * @offs_boot: Offset clock monotonic -> clock boottime 49 * @offs_tai: Offset clock monotonic -> clock tai 50 * @tai_offset: The current UTC to TAI offset in seconds 51 * @clock_was_set_seq: The sequence number of clock was set events 52 * @cs_was_changed_seq: The sequence number of clocksource change events 53 * @next_leap_ktime: CLOCK_MONOTONIC time value of a pending leap-second 54 * @raw_sec: CLOCK_MONOTONIC_RAW time in seconds 55 * @cycle_interval: Number of clock cycles in one NTP interval 56 * @xtime_interval: Number of clock shifted nano seconds in one NTP 57 * interval. 58 * @xtime_remainder: Shifted nano seconds left over when rounding 59 * @cycle_interval 60 * @raw_interval: Shifted raw nano seconds accumulated per NTP interval. 61 * @ntp_error: Difference between accumulated time and NTP time in ntp 62 * shifted nano seconds. 63 * @ntp_error_shift: Shift conversion between clock shifted nano seconds and 64 * ntp shifted nano seconds. 65 * @last_warning: Warning ratelimiter (DEBUG_TIMEKEEPING) 66 * @underflow_seen: Underflow warning flag (DEBUG_TIMEKEEPING) 67 * @overflow_seen: Overflow warning flag (DEBUG_TIMEKEEPING) 68 * 69 * Note: For timespec(64) based interfaces wall_to_monotonic is what 70 * we need to add to xtime (or xtime corrected for sub jiffie times) 71 * to get to monotonic time. Monotonic is pegged at zero at system 72 * boot time, so wall_to_monotonic will be negative, however, we will 73 * ALWAYS keep the tv_nsec part positive so we can use the usual 74 * normalization. 75 * 76 * wall_to_monotonic is moved after resume from suspend for the 77 * monotonic time not to jump. We need to add total_sleep_time to 78 * wall_to_monotonic to get the real boot based time offset. 79 * 80 * wall_to_monotonic is no longer the boot time, getboottime must be 81 * used instead. 82 */ 83 struct timekeeper { 84 struct tk_read_base tkr_mono; 85 struct tk_read_base tkr_raw; 86 u64 xtime_sec; 87 unsigned long ktime_sec; 88 struct timespec64 wall_to_monotonic; 89 ktime_t offs_real; 90 ktime_t offs_boot; 91 ktime_t offs_tai; 92 s32 tai_offset; 93 unsigned int clock_was_set_seq; 94 u8 cs_was_changed_seq; 95 ktime_t next_leap_ktime; 96 u64 raw_sec; 97 98 /* The following members are for timekeeping internal use */ 99 u64 cycle_interval; 100 u64 xtime_interval; 101 s64 xtime_remainder; 102 u64 raw_interval; 103 /* The ntp_tick_length() value currently being used. 104 * This cached copy ensures we consistently apply the tick 105 * length for an entire tick, as ntp_tick_length may change 106 * mid-tick, and we don't want to apply that new value to 107 * the tick in progress. 108 */ 109 u64 ntp_tick; 110 /* Difference between accumulated time and NTP time in ntp 111 * shifted nano seconds. */ 112 s64 ntp_error; 113 u32 ntp_error_shift; 114 u32 ntp_err_mult; 115 #ifdef CONFIG_DEBUG_TIMEKEEPING 116 long last_warning; 117 /* 118 * These simple flag variables are managed 119 * without locks, which is racy, but they are 120 * ok since we don't really care about being 121 * super precise about how many events were 122 * seen, just that a problem was observed. 123 */ 124 int underflow_seen; 125 int overflow_seen; 126 #endif 127 }; 128 129 #ifdef CONFIG_GENERIC_TIME_VSYSCALL 130 131 extern void update_vsyscall(struct timekeeper *tk); 132 extern void update_vsyscall_tz(void); 133 134 #elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD) 135 136 extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm, 137 struct clocksource *c, u32 mult, 138 u64 cycle_last); 139 extern void update_vsyscall_tz(void); 140 141 #else 142 143 static inline void update_vsyscall(struct timekeeper *tk) 144 { 145 } 146 static inline void update_vsyscall_tz(void) 147 { 148 } 149 #endif 150 151 #endif /* _LINUX_TIMEKEEPER_INTERNAL_H */ 152