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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
d7b4202e JS |
2 | /* |
3 | * You SHOULD NOT be including this unless you're vsyscall | |
4 | * handling code or timekeeping internal code! | |
5 | */ | |
6 | ||
7 | #ifndef _LINUX_TIMEKEEPER_INTERNAL_H | |
8 | #define _LINUX_TIMEKEEPER_INTERNAL_H | |
9 | ||
10 | #include <linux/clocksource.h> | |
11 | #include <linux/jiffies.h> | |
12 | #include <linux/time.h> | |
13 | ||
d28ede83 TG |
14 | /** |
15 | * struct tk_read_base - base structure for timekeeping readout | |
16 | * @clock: Current clocksource used for timekeeping. | |
d28ede83 TG |
17 | * @mask: Bitmask for two's complement subtraction of non 64bit clocks |
18 | * @cycle_last: @clock cycle value at last update | |
876e7881 | 19 | * @mult: (NTP adjusted) multiplier for scaled math conversion |
d28ede83 TG |
20 | * @shift: Shift value for scaled math conversion |
21 | * @xtime_nsec: Shifted (fractional) nano seconds offset for readout | |
876e7881 | 22 | * @base: ktime_t (nanoseconds) base time for readout |
4c3711d7 | 23 | * @base_real: Nanoseconds base value for clock REALTIME readout |
3fdb14fd | 24 | * |
d28ede83 TG |
25 | * This struct has size 56 byte on 64 bit. Together with a seqcount it |
26 | * occupies a single 64byte cache line. | |
3fdb14fd | 27 | * |
d28ede83 | 28 | * The struct is separate from struct timekeeper as it is also used |
876e7881 | 29 | * for a fast NMI safe accessors. |
4c3711d7 TG |
30 | * |
31 | * @base_real is for the fast NMI safe accessor to allow reading clock | |
32 | * realtime from any context. | |
3fdb14fd | 33 | */ |
d28ede83 | 34 | struct tk_read_base { |
d7b4202e | 35 | struct clocksource *clock; |
a5a1d1c2 TG |
36 | u64 mask; |
37 | u64 cycle_last; | |
d7b4202e | 38 | u32 mult; |
d7b4202e | 39 | u32 shift; |
3fdb14fd | 40 | u64 xtime_nsec; |
876e7881 | 41 | ktime_t base; |
4c3711d7 | 42 | u64 base_real; |
d28ede83 | 43 | }; |
7c032df5 | 44 | |
d28ede83 TG |
45 | /** |
46 | * struct timekeeper - Structure holding internal timekeeping values. | |
876e7881 | 47 | * @tkr_mono: The readout base structure for CLOCK_MONOTONIC |
4a4ad80d | 48 | * @tkr_raw: The readout base structure for CLOCK_MONOTONIC_RAW |
d28ede83 | 49 | * @xtime_sec: Current CLOCK_REALTIME time in seconds |
9e3680b1 | 50 | * @ktime_sec: Current CLOCK_MONOTONIC time in seconds |
d28ede83 TG |
51 | * @wall_to_monotonic: CLOCK_REALTIME to CLOCK_MONOTONIC offset |
52 | * @offs_real: Offset clock monotonic -> clock realtime | |
53 | * @offs_boot: Offset clock monotonic -> clock boottime | |
54 | * @offs_tai: Offset clock monotonic -> clock tai | |
55 | * @tai_offset: The current UTC to TAI offset in seconds | |
868a3e91 | 56 | * @clock_was_set_seq: The sequence number of clock was set events |
2c756feb | 57 | * @cs_was_changed_seq: The sequence number of clocksource change events |
833f32d7 | 58 | * @next_leap_ktime: CLOCK_MONOTONIC time value of a pending leap-second |
fc6eead7 | 59 | * @raw_sec: CLOCK_MONOTONIC_RAW time in seconds |
d28ede83 TG |
60 | * @cycle_interval: Number of clock cycles in one NTP interval |
61 | * @xtime_interval: Number of clock shifted nano seconds in one NTP | |
62 | * interval. | |
63 | * @xtime_remainder: Shifted nano seconds left over when rounding | |
64 | * @cycle_interval | |
3d88d56c | 65 | * @raw_interval: Shifted raw nano seconds accumulated per NTP interval. |
d28ede83 TG |
66 | * @ntp_error: Difference between accumulated time and NTP time in ntp |
67 | * shifted nano seconds. | |
68 | * @ntp_error_shift: Shift conversion between clock shifted nano seconds and | |
69 | * ntp shifted nano seconds. | |
57d05a93 JS |
70 | * @last_warning: Warning ratelimiter (DEBUG_TIMEKEEPING) |
71 | * @underflow_seen: Underflow warning flag (DEBUG_TIMEKEEPING) | |
72 | * @overflow_seen: Overflow warning flag (DEBUG_TIMEKEEPING) | |
d28ede83 TG |
73 | * |
74 | * Note: For timespec(64) based interfaces wall_to_monotonic is what | |
75 | * we need to add to xtime (or xtime corrected for sub jiffie times) | |
76 | * to get to monotonic time. Monotonic is pegged at zero at system | |
77 | * boot time, so wall_to_monotonic will be negative, however, we will | |
78 | * ALWAYS keep the tv_nsec part positive so we can use the usual | |
79 | * normalization. | |
80 | * | |
81 | * wall_to_monotonic is moved after resume from suspend for the | |
82 | * monotonic time not to jump. We need to add total_sleep_time to | |
83 | * wall_to_monotonic to get the real boot based time offset. | |
84 | * | |
85 | * wall_to_monotonic is no longer the boot time, getboottime must be | |
86 | * used instead. | |
87 | */ | |
88 | struct timekeeper { | |
876e7881 | 89 | struct tk_read_base tkr_mono; |
4a4ad80d | 90 | struct tk_read_base tkr_raw; |
3fdb14fd | 91 | u64 xtime_sec; |
9e3680b1 | 92 | unsigned long ktime_sec; |
3fdb14fd | 93 | struct timespec64 wall_to_monotonic; |
3fdb14fd | 94 | ktime_t offs_real; |
3fdb14fd | 95 | ktime_t offs_boot; |
3fdb14fd | 96 | ktime_t offs_tai; |
3fdb14fd | 97 | s32 tai_offset; |
868a3e91 | 98 | unsigned int clock_was_set_seq; |
2c756feb | 99 | u8 cs_was_changed_seq; |
833f32d7 | 100 | ktime_t next_leap_ktime; |
fc6eead7 | 101 | u64 raw_sec; |
3fdb14fd | 102 | |
d28ede83 | 103 | /* The following members are for timekeeping internal use */ |
a5a1d1c2 | 104 | u64 cycle_interval; |
d7b4202e | 105 | u64 xtime_interval; |
d7b4202e | 106 | s64 xtime_remainder; |
3d88d56c | 107 | u64 raw_interval; |
375f45b5 JS |
108 | /* The ntp_tick_length() value currently being used. |
109 | * This cached copy ensures we consistently apply the tick | |
110 | * length for an entire tick, as ntp_tick_length may change | |
111 | * mid-tick, and we don't want to apply that new value to | |
112 | * the tick in progress. | |
113 | */ | |
114 | u64 ntp_tick; | |
115 | /* Difference between accumulated time and NTP time in ntp | |
116 | * shifted nano seconds. */ | |
d7b4202e | 117 | s64 ntp_error; |
3fdb14fd | 118 | u32 ntp_error_shift; |
dc491596 | 119 | u32 ntp_err_mult; |
78b98e3c ML |
120 | /* Flag used to avoid updating NTP twice with same second */ |
121 | u32 skip_second_overflow; | |
57d05a93 JS |
122 | #ifdef CONFIG_DEBUG_TIMEKEEPING |
123 | long last_warning; | |
124 | /* | |
125 | * These simple flag variables are managed | |
126 | * without locks, which is racy, but they are | |
127 | * ok since we don't really care about being | |
128 | * super precise about how many events were | |
129 | * seen, just that a problem was observed. | |
130 | */ | |
131 | int underflow_seen; | |
132 | int overflow_seen; | |
133 | #endif | |
d7b4202e | 134 | }; |
189374ae | 135 | |
576094b7 JS |
136 | #ifdef CONFIG_GENERIC_TIME_VSYSCALL |
137 | ||
138 | extern void update_vsyscall(struct timekeeper *tk); | |
139 | extern void update_vsyscall_tz(void); | |
189374ae | 140 | |
189374ae | 141 | #else |
576094b7 JS |
142 | |
143 | static inline void update_vsyscall(struct timekeeper *tk) | |
189374ae JS |
144 | { |
145 | } | |
146 | static inline void update_vsyscall_tz(void) | |
147 | { | |
148 | } | |
149 | #endif | |
150 | ||
d7b4202e | 151 | #endif /* _LINUX_TIMEKEEPER_INTERNAL_H */ |