1 /********************************************* 1 /*****************************************************************************
2 * 2 * *
3 * Copyright (c) David L. Mills 1993 3 * Copyright (c) David L. Mills 1993 *
4 * 4 * *
5 * Permission to use, copy, modify, and distri 5 * Permission to use, copy, modify, and distribute this software and its *
6 * documentation for any purpose and without f 6 * documentation for any purpose and without fee is hereby granted, provided *
7 * that the above copyright notice appears in 7 * that the above copyright notice appears in all copies and that both the *
8 * copyright notice and this permission notice 8 * copyright notice and this permission notice appear in supporting *
9 * documentation, and that the name University 9 * documentation, and that the name University of Delaware not be used in *
10 * advertising or publicity pertaining to dist 10 * advertising or publicity pertaining to distribution of the software *
11 * without specific, written prior permission. 11 * without specific, written prior permission. The University of Delaware *
12 * makes no representations about the suitabil 12 * makes no representations about the suitability this software for any *
13 * purpose. It is provided "as is" without ex 13 * purpose. It is provided "as is" without express or implied warranty. *
14 * 14 * *
15 ********************************************* 15 *****************************************************************************/
16 16
17 /* 17 /*
18 * Modification history timex.h 18 * Modification history timex.h
19 * 19 *
20 * 29 Dec 97 Russell King 20 * 29 Dec 97 Russell King
21 * Moved CLOCK_TICK_RATE, CLOCK_TICK_FACT 21 * Moved CLOCK_TICK_RATE, CLOCK_TICK_FACTOR and FINETUNE to asm/timex.h
22 * for ARM machines 22 * for ARM machines
23 * 23 *
24 * 9 Jan 97 Adrian Sun 24 * 9 Jan 97 Adrian Sun
25 * Shifted LATCH define to allow access t 25 * Shifted LATCH define to allow access to alpha machines.
26 * 26 *
27 * 26 Sep 94 David L. Mills 27 * 26 Sep 94 David L. Mills
28 * Added defines for hybrid phase/frequen 28 * Added defines for hybrid phase/frequency-lock loop.
29 * 29 *
30 * 19 Mar 94 David L. Mills 30 * 19 Mar 94 David L. Mills
31 * Moved defines from kernel routines to 31 * Moved defines from kernel routines to header file and added new
32 * defines for PPS phase-lock loop. 32 * defines for PPS phase-lock loop.
33 * 33 *
34 * 20 Feb 94 David L. Mills 34 * 20 Feb 94 David L. Mills
35 * Revised status codes and structures fo 35 * Revised status codes and structures for external clock and PPS
36 * signal discipline. 36 * signal discipline.
37 * 37 *
38 * 28 Nov 93 David L. Mills 38 * 28 Nov 93 David L. Mills
39 * Adjusted parameters to improve stabili 39 * Adjusted parameters to improve stability and increase poll
40 * interval. 40 * interval.
41 * 41 *
42 * 17 Sep 93 David L. Mills 42 * 17 Sep 93 David L. Mills
43 * Created file $NTP/include/sys/timex.h 43 * Created file $NTP/include/sys/timex.h
44 * 07 Oct 93 Torsten Duwe 44 * 07 Oct 93 Torsten Duwe
45 * Derived linux/timex.h 45 * Derived linux/timex.h
46 * 1995-08-13 Torsten Duwe 46 * 1995-08-13 Torsten Duwe
47 * kernel PLL updated to 1994-12-13 specs 47 * kernel PLL updated to 1994-12-13 specs (rfc-1589)
48 * 1997-08-30 Ulrich Windl 48 * 1997-08-30 Ulrich Windl
49 * Added new constant NTP_PHASE_LIMIT 49 * Added new constant NTP_PHASE_LIMIT
50 * 2004-08-12 Christoph Lameter 50 * 2004-08-12 Christoph Lameter
51 * Reworked time interpolation logic 51 * Reworked time interpolation logic
52 */ 52 */
53 #ifndef _LINUX_TIMEX_H 53 #ifndef _LINUX_TIMEX_H
54 #define _LINUX_TIMEX_H 54 #define _LINUX_TIMEX_H
55 55
56 #include <uapi/linux/timex.h> !! 56 #include <linux/time.h>
57 57
>> 58 #define NTP_API 4 /* NTP API version */
>> 59
>> 60 /*
>> 61 * syscall interface - used (mainly by NTP daemon)
>> 62 * to discipline kernel clock oscillator
>> 63 */
>> 64 struct timex {
>> 65 unsigned int modes; /* mode selector */
>> 66 long offset; /* time offset (usec) */
>> 67 long freq; /* frequency offset (scaled ppm) */
>> 68 long maxerror; /* maximum error (usec) */
>> 69 long esterror; /* estimated error (usec) */
>> 70 int status; /* clock command/status */
>> 71 long constant; /* pll time constant */
>> 72 long precision; /* clock precision (usec) (read only) */
>> 73 long tolerance; /* clock frequency tolerance (ppm)
>> 74 * (read only)
>> 75 */
>> 76 struct timeval time; /* (read only) */
>> 77 long tick; /* (modified) usecs between clock ticks */
>> 78
>> 79 long ppsfreq; /* pps frequency (scaled ppm) (ro) */
>> 80 long jitter; /* pps jitter (us) (ro) */
>> 81 int shift; /* interval duration (s) (shift) (ro) */
>> 82 long stabil; /* pps stability (scaled ppm) (ro) */
>> 83 long jitcnt; /* jitter limit exceeded (ro) */
>> 84 long calcnt; /* calibration intervals (ro) */
>> 85 long errcnt; /* calibration errors (ro) */
>> 86 long stbcnt; /* stability limit exceeded (ro) */
>> 87
>> 88 int tai; /* TAI offset (ro) */
>> 89
>> 90 int :32; int :32; int :32; int :32;
>> 91 int :32; int :32; int :32; int :32;
>> 92 int :32; int :32; int :32;
>> 93 };
>> 94
>> 95 /*
>> 96 * Mode codes (timex.mode)
>> 97 */
>> 98 #define ADJ_OFFSET 0x0001 /* time offset */
>> 99 #define ADJ_FREQUENCY 0x0002 /* frequency offset */
>> 100 #define ADJ_MAXERROR 0x0004 /* maximum time error */
>> 101 #define ADJ_ESTERROR 0x0008 /* estimated time error */
>> 102 #define ADJ_STATUS 0x0010 /* clock status */
>> 103 #define ADJ_TIMECONST 0x0020 /* pll time constant */
>> 104 #define ADJ_TAI 0x0080 /* set TAI offset */
>> 105 #define ADJ_MICRO 0x1000 /* select microsecond resolution */
>> 106 #define ADJ_NANO 0x2000 /* select nanosecond resolution */
>> 107 #define ADJ_TICK 0x4000 /* tick value */
>> 108
>> 109 #ifdef __KERNEL__
58 #define ADJ_ADJTIME 0x8000 /* swi 110 #define ADJ_ADJTIME 0x8000 /* switch between adjtime/adjtimex modes */
59 #define ADJ_OFFSET_SINGLESHOT 0x0001 /* old 111 #define ADJ_OFFSET_SINGLESHOT 0x0001 /* old-fashioned adjtime */
60 #define ADJ_OFFSET_READONLY 0x2000 /* rea 112 #define ADJ_OFFSET_READONLY 0x2000 /* read-only adjtime */
61 #include <linux/compiler.h> !! 113 #else
62 #include <linux/types.h> !! 114 #define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
63 #include <linux/param.h> !! 115 #define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */
>> 116 #endif
64 117
65 unsigned long random_get_entropy_fallback(void !! 118 /* xntp 3.4 compatibility names */
>> 119 #define MOD_OFFSET ADJ_OFFSET
>> 120 #define MOD_FREQUENCY ADJ_FREQUENCY
>> 121 #define MOD_MAXERROR ADJ_MAXERROR
>> 122 #define MOD_ESTERROR ADJ_ESTERROR
>> 123 #define MOD_STATUS ADJ_STATUS
>> 124 #define MOD_TIMECONST ADJ_TIMECONST
66 125
67 #include <asm/timex.h> <<
68 126
69 #ifndef random_get_entropy <<
70 /* 127 /*
71 * The random_get_entropy() function is used b !! 128 * Status codes (timex.status)
72 * in order to extract entropy via the relativ <<
73 * when an interrupt takes places versus a hig <<
74 * timing source or cycle counter. Since it w <<
75 * single interrupt, it must have a very low c <<
76 * <<
77 * By default we use get_cycles() for this pur <<
78 * architectures may override this in their as <<
79 * If a given arch does not have get_cycles(), <<
80 * using random_get_entropy_fallback(). <<
81 */ 129 */
82 #ifdef get_cycles !! 130 #define STA_PLL 0x0001 /* enable PLL updates (rw) */
83 #define random_get_entropy() ((unsigned lon !! 131 #define STA_PPSFREQ 0x0002 /* enable PPS freq discipline (rw) */
84 #else !! 132 #define STA_PPSTIME 0x0004 /* enable PPS time discipline (rw) */
85 #define random_get_entropy() random_get_ent !! 133 #define STA_FLL 0x0008 /* select frequency-lock mode (rw) */
86 #endif !! 134
87 #endif !! 135 #define STA_INS 0x0010 /* insert leap (rw) */
>> 136 #define STA_DEL 0x0020 /* delete leap (rw) */
>> 137 #define STA_UNSYNC 0x0040 /* clock unsynchronized (rw) */
>> 138 #define STA_FREQHOLD 0x0080 /* hold frequency (rw) */
>> 139
>> 140 #define STA_PPSSIGNAL 0x0100 /* PPS signal present (ro) */
>> 141 #define STA_PPSJITTER 0x0200 /* PPS signal jitter exceeded (ro) */
>> 142 #define STA_PPSWANDER 0x0400 /* PPS signal wander exceeded (ro) */
>> 143 #define STA_PPSERROR 0x0800 /* PPS signal calibration error (ro) */
>> 144
>> 145 #define STA_CLOCKERR 0x1000 /* clock hardware fault (ro) */
>> 146 #define STA_NANO 0x2000 /* resolution (0 = us, 1 = ns) (ro) */
>> 147 #define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */
>> 148 #define STA_CLK 0x8000 /* clock source (0 = A, 1 = B) (ro) */
>> 149
>> 150 /* read-only bits */
>> 151 #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
>> 152 STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK)
>> 153
>> 154 /*
>> 155 * Clock states (time_state)
>> 156 */
>> 157 #define TIME_OK 0 /* clock synchronized, no leap second */
>> 158 #define TIME_INS 1 /* insert leap second */
>> 159 #define TIME_DEL 2 /* delete leap second */
>> 160 #define TIME_OOP 3 /* leap second in progress */
>> 161 #define TIME_WAIT 4 /* leap second has occurred */
>> 162 #define TIME_ERROR 5 /* clock not synchronized */
>> 163 #define TIME_BAD TIME_ERROR /* bw compat */
>> 164
>> 165 #ifdef __KERNEL__
>> 166 #include <linux/compiler.h>
>> 167 #include <linux/types.h>
>> 168 #include <linux/param.h>
>> 169
>> 170 #include <asm/timex.h>
88 171
89 /* 172 /*
90 * SHIFT_PLL is used as a dampening factor to 173 * SHIFT_PLL is used as a dampening factor to define how much we
91 * adjust the frequency correction for a given 174 * adjust the frequency correction for a given offset in PLL mode.
92 * It also used in dampening the offset correc 175 * It also used in dampening the offset correction, to define how
93 * much of the current value in time_offset we 176 * much of the current value in time_offset we correct for each
94 * second. Changing this value changes the sti 177 * second. Changing this value changes the stiffness of the ntp
95 * adjustment code. A lower value makes it mor 178 * adjustment code. A lower value makes it more flexible, reducing
96 * NTP convergence time. A higher value makes 179 * NTP convergence time. A higher value makes it stiffer, increasing
97 * convergence time, but making the clock more 180 * convergence time, but making the clock more stable.
98 * 181 *
99 * In David Mills' nanokernel reference implem 182 * In David Mills' nanokernel reference implementation SHIFT_PLL is 4.
100 * However this seems to increase convergence 183 * However this seems to increase convergence time much too long.
101 * 184 *
102 * https://lists.ntp.org/pipermail/hackers/200 185 * https://lists.ntp.org/pipermail/hackers/2008-January/003487.html
103 * 186 *
104 * In the above mailing list discussion, it se 187 * In the above mailing list discussion, it seems the value of 4
105 * was appropriate for other Unix systems with 188 * was appropriate for other Unix systems with HZ=100, and that
106 * SHIFT_PLL should be decreased as HZ increas 189 * SHIFT_PLL should be decreased as HZ increases. However, Linux's
107 * clock steering implementation is HZ indepen 190 * clock steering implementation is HZ independent.
108 * 191 *
109 * Through experimentation, a SHIFT_PLL value 192 * Through experimentation, a SHIFT_PLL value of 2 was found to allow
110 * for fast convergence (very similar to the N 193 * for fast convergence (very similar to the NTPv3 code used prior to
111 * v2.6.19), with good clock stability. 194 * v2.6.19), with good clock stability.
112 * 195 *
113 * 196 *
114 * SHIFT_FLL is used as a dampening factor to 197 * SHIFT_FLL is used as a dampening factor to define how much we
115 * adjust the frequency correction for a given 198 * adjust the frequency correction for a given offset in FLL mode.
116 * In David Mills' nanokernel reference implem 199 * In David Mills' nanokernel reference implementation SHIFT_FLL is 2.
117 * 200 *
118 * MAXTC establishes the maximum time constant 201 * MAXTC establishes the maximum time constant of the PLL.
119 */ 202 */
120 #define SHIFT_PLL 2 /* PLL frequen 203 #define SHIFT_PLL 2 /* PLL frequency factor (shift) */
121 #define SHIFT_FLL 2 /* FLL frequen 204 #define SHIFT_FLL 2 /* FLL frequency factor (shift) */
122 #define MAXTC 10 /* maximum tim 205 #define MAXTC 10 /* maximum time constant (shift) */
123 206
124 /* 207 /*
125 * SHIFT_USEC defines the scaling (shift) of t 208 * SHIFT_USEC defines the scaling (shift) of the time_freq and
126 * time_tolerance variables, which represent t 209 * time_tolerance variables, which represent the current frequency
127 * offset and maximum frequency tolerance. 210 * offset and maximum frequency tolerance.
128 */ 211 */
129 #define SHIFT_USEC 16 /* frequency o 212 #define SHIFT_USEC 16 /* frequency offset scale (shift) */
130 #define PPM_SCALE ((s64)NSEC_PER_USEC << (NTP_ 213 #define PPM_SCALE ((s64)NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC))
131 #define PPM_SCALE_INV_SHIFT 19 214 #define PPM_SCALE_INV_SHIFT 19
132 #define PPM_SCALE_INV ((1LL << (PPM_SCALE_INV_ 215 #define PPM_SCALE_INV ((1LL << (PPM_SCALE_INV_SHIFT + NTP_SCALE_SHIFT)) / \
133 PPM_SCALE + 1) 216 PPM_SCALE + 1)
134 217
135 #define MAXPHASE 500000000L /* max phase e 218 #define MAXPHASE 500000000L /* max phase error (ns) */
136 #define MAXFREQ 500000 /* max frequen 219 #define MAXFREQ 500000 /* max frequency error (ns/s) */
137 #define MAXFREQ_SCALED ((s64)MAXFREQ << NTP_SC 220 #define MAXFREQ_SCALED ((s64)MAXFREQ << NTP_SCALE_SHIFT)
138 #define MINSEC 256 /* min interva 221 #define MINSEC 256 /* min interval between updates (s) */
139 #define MAXSEC 2048 /* max interva 222 #define MAXSEC 2048 /* max interval between updates (s) */
140 #define NTP_PHASE_LIMIT ((MAXPHASE / NSEC_PER_ 223 #define NTP_PHASE_LIMIT ((MAXPHASE / NSEC_PER_USEC) << 5) /* beyond max. dispersion */
141 224
142 /* 225 /*
143 * kernel variables 226 * kernel variables
144 * Note: maximum error = NTP sync distance = d !! 227 * Note: maximum error = NTP synch distance = dispersion + delay / 2;
145 * estimated error = NTP dispersion. 228 * estimated error = NTP dispersion.
146 */ 229 */
147 extern unsigned long tick_usec; /* USE 230 extern unsigned long tick_usec; /* USER_HZ period (usec) */
148 extern unsigned long tick_nsec; /* SHI !! 231 extern unsigned long tick_nsec; /* ACTHZ period (nsec) */
>> 232 extern int tickadj; /* amount of adjustment per tick */
>> 233
>> 234 /*
>> 235 * phase-lock loop variables
>> 236 */
>> 237 extern int time_status; /* clock synchronization status bits */
>> 238 extern long time_maxerror; /* maximum error */
>> 239 extern long time_esterror; /* estimated error */
>> 240
>> 241 extern long time_adjust; /* The amount of adjtime left */
>> 242
>> 243 extern void ntp_init(void);
>> 244 extern void ntp_clear(void);
>> 245
>> 246 /**
>> 247 * ntp_synced - Returns 1 if the NTP status is not UNSYNC
>> 248 *
>> 249 */
>> 250 static inline int ntp_synced(void)
>> 251 {
>> 252 return !(time_status & STA_UNSYNC);
>> 253 }
149 254
150 /* Required to safely shift negative values */ 255 /* Required to safely shift negative values */
151 #define shift_right(x, s) ({ \ 256 #define shift_right(x, s) ({ \
152 __typeof__(x) __x = (x); \ 257 __typeof__(x) __x = (x); \
153 __typeof__(s) __s = (s); \ 258 __typeof__(s) __s = (s); \
154 __x < 0 ? -(-__x >> __s) : __x >> __s; 259 __x < 0 ? -(-__x >> __s) : __x >> __s; \
155 }) 260 })
156 261
157 #define NTP_SCALE_SHIFT 32 262 #define NTP_SCALE_SHIFT 32
158 263
>> 264 #ifdef CONFIG_NO_HZ
>> 265 #define NTP_INTERVAL_FREQ (2)
>> 266 #else
159 #define NTP_INTERVAL_FREQ (HZ) 267 #define NTP_INTERVAL_FREQ (HZ)
>> 268 #endif
160 #define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_ 269 #define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)
161 270
162 extern int do_adjtimex(struct __kernel_timex * !! 271 /* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */
163 extern int do_clock_adjtime(const clockid_t wh !! 272 extern u64 tick_length;
164 273
165 extern void hardpps(const struct timespec64 *, !! 274 extern int second_overflow(unsigned long secs);
>> 275 extern void update_ntp_one_tick(void);
>> 276 extern int do_adjtimex(struct timex *);
>> 277
>> 278 /* Don't use! Compatibility define for existing users. */
>> 279 #define tickadj (500/HZ ? : 1)
166 280
167 int read_current_timer(unsigned long *timer_va 281 int read_current_timer(unsigned long *timer_val);
168 282
169 /* The clock frequency of the i8253/i8254 PIT 283 /* The clock frequency of the i8253/i8254 PIT */
170 #define PIT_TICK_RATE 1193182ul 284 #define PIT_TICK_RATE 1193182ul
>> 285
>> 286 #endif /* KERNEL */
171 287
172 #endif /* LINUX_TIMEX_H */ 288 #endif /* LINUX_TIMEX_H */
173 289
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