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-rw-r--r--kernel/time/Makefile2
-rw-r--r--kernel/time/clockevents.c20
-rw-r--r--kernel/time/clocksource.c76
-rw-r--r--kernel/time/ntp.c444
-rw-r--r--kernel/time/timecompare.c191
5 files changed, 553 insertions, 180 deletions
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 905b0b50792d..0b0a6366c9d4 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -1,4 +1,4 @@
1obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o 1obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o timecompare.o
2 2
3obj-$(CONFIG_GENERIC_CLOCKEVENTS_BUILD) += clockevents.o 3obj-$(CONFIG_GENERIC_CLOCKEVENTS_BUILD) += clockevents.o
4obj-$(CONFIG_GENERIC_CLOCKEVENTS) += tick-common.o 4obj-$(CONFIG_GENERIC_CLOCKEVENTS) += tick-common.o
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index ea2f48af83cf..d13be216a790 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -68,6 +68,17 @@ void clockevents_set_mode(struct clock_event_device *dev,
68 if (dev->mode != mode) { 68 if (dev->mode != mode) {
69 dev->set_mode(mode, dev); 69 dev->set_mode(mode, dev);
70 dev->mode = mode; 70 dev->mode = mode;
71
72 /*
73 * A nsec2cyc multiplicator of 0 is invalid and we'd crash
74 * on it, so fix it up and emit a warning:
75 */
76 if (mode == CLOCK_EVT_MODE_ONESHOT) {
77 if (unlikely(!dev->mult)) {
78 dev->mult = 1;
79 WARN_ON(1);
80 }
81 }
71 } 82 }
72} 83}
73 84
@@ -168,15 +179,6 @@ void clockevents_register_device(struct clock_event_device *dev)
168 BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); 179 BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
169 BUG_ON(!dev->cpumask); 180 BUG_ON(!dev->cpumask);
170 181
171 /*
172 * A nsec2cyc multiplicator of 0 is invalid and we'd crash
173 * on it, so fix it up and emit a warning:
174 */
175 if (unlikely(!dev->mult)) {
176 dev->mult = 1;
177 WARN_ON(1);
178 }
179
180 spin_lock(&clockevents_lock); 182 spin_lock(&clockevents_lock);
181 183
182 list_add(&dev->list, &clockevent_devices); 184 list_add(&dev->list, &clockevent_devices);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index ca89e1593f08..c46c931a7fe7 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -31,6 +31,82 @@
31#include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */ 31#include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */
32#include <linux/tick.h> 32#include <linux/tick.h>
33 33
34void timecounter_init(struct timecounter *tc,
35 const struct cyclecounter *cc,
36 u64 start_tstamp)
37{
38 tc->cc = cc;
39 tc->cycle_last = cc->read(cc);
40 tc->nsec = start_tstamp;
41}
42EXPORT_SYMBOL(timecounter_init);
43
44/**
45 * timecounter_read_delta - get nanoseconds since last call of this function
46 * @tc: Pointer to time counter
47 *
48 * When the underlying cycle counter runs over, this will be handled
49 * correctly as long as it does not run over more than once between
50 * calls.
51 *
52 * The first call to this function for a new time counter initializes
53 * the time tracking and returns an undefined result.
54 */
55static u64 timecounter_read_delta(struct timecounter *tc)
56{
57 cycle_t cycle_now, cycle_delta;
58 u64 ns_offset;
59
60 /* read cycle counter: */
61 cycle_now = tc->cc->read(tc->cc);
62
63 /* calculate the delta since the last timecounter_read_delta(): */
64 cycle_delta = (cycle_now - tc->cycle_last) & tc->cc->mask;
65
66 /* convert to nanoseconds: */
67 ns_offset = cyclecounter_cyc2ns(tc->cc, cycle_delta);
68
69 /* update time stamp of timecounter_read_delta() call: */
70 tc->cycle_last = cycle_now;
71
72 return ns_offset;
73}
74
75u64 timecounter_read(struct timecounter *tc)
76{
77 u64 nsec;
78
79 /* increment time by nanoseconds since last call */
80 nsec = timecounter_read_delta(tc);
81 nsec += tc->nsec;
82 tc->nsec = nsec;
83
84 return nsec;
85}
86EXPORT_SYMBOL(timecounter_read);
87
88u64 timecounter_cyc2time(struct timecounter *tc,
89 cycle_t cycle_tstamp)
90{
91 u64 cycle_delta = (cycle_tstamp - tc->cycle_last) & tc->cc->mask;
92 u64 nsec;
93
94 /*
95 * Instead of always treating cycle_tstamp as more recent
96 * than tc->cycle_last, detect when it is too far in the
97 * future and treat it as old time stamp instead.
98 */
99 if (cycle_delta > tc->cc->mask / 2) {
100 cycle_delta = (tc->cycle_last - cycle_tstamp) & tc->cc->mask;
101 nsec = tc->nsec - cyclecounter_cyc2ns(tc->cc, cycle_delta);
102 } else {
103 nsec = cyclecounter_cyc2ns(tc->cc, cycle_delta) + tc->nsec;
104 }
105
106 return nsec;
107}
108EXPORT_SYMBOL(timecounter_cyc2time);
109
34/* XXX - Would like a better way for initializing curr_clocksource */ 110/* XXX - Would like a better way for initializing curr_clocksource */
35extern struct clocksource clocksource_jiffies; 111extern struct clocksource clocksource_jiffies;
36 112
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index f5f793d92415..7fc64375ff43 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -1,71 +1,129 @@
1/* 1/*
2 * linux/kernel/time/ntp.c
3 *
4 * NTP state machine interfaces and logic. 2 * NTP state machine interfaces and logic.
5 * 3 *
6 * This code was mainly moved from kernel/timer.c and kernel/time.c 4 * This code was mainly moved from kernel/timer.c and kernel/time.c
7 * Please see those files for relevant copyright info and historical 5 * Please see those files for relevant copyright info and historical
8 * changelogs. 6 * changelogs.
9 */ 7 */
10
11#include <linux/mm.h>
12#include <linux/time.h>
13#include <linux/timex.h>
14#include <linux/jiffies.h>
15#include <linux/hrtimer.h>
16#include <linux/capability.h> 8#include <linux/capability.h>
17#include <linux/math64.h>
18#include <linux/clocksource.h> 9#include <linux/clocksource.h>
19#include <linux/workqueue.h> 10#include <linux/workqueue.h>
20#include <asm/timex.h> 11#include <linux/hrtimer.h>
12#include <linux/jiffies.h>
13#include <linux/math64.h>
14#include <linux/timex.h>
15#include <linux/time.h>
16#include <linux/mm.h>
21 17
22/* 18/*
23 * Timekeeping variables 19 * NTP timekeeping variables:
24 */ 20 */
25unsigned long tick_usec = TICK_USEC; /* USER_HZ period (usec) */
26unsigned long tick_nsec; /* ACTHZ period (nsec) */
27u64 tick_length;
28static u64 tick_length_base;
29 21
30static struct hrtimer leap_timer; 22/* USER_HZ period (usecs): */
23unsigned long tick_usec = TICK_USEC;
31 24
32#define MAX_TICKADJ 500 /* microsecs */ 25/* ACTHZ period (nsecs): */
33#define MAX_TICKADJ_SCALED (((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \ 26unsigned long tick_nsec;
34 NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ) 27
28u64 tick_length;
29static u64 tick_length_base;
30
31static struct hrtimer leap_timer;
32
33#define MAX_TICKADJ 500LL /* usecs */
34#define MAX_TICKADJ_SCALED \
35 (((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
35 36
36/* 37/*
37 * phase-lock loop variables 38 * phase-lock loop variables
38 */ 39 */
39/* TIME_ERROR prevents overwriting the CMOS clock */
40static int time_state = TIME_OK; /* clock synchronization status */
41int time_status = STA_UNSYNC; /* clock status bits */
42static long time_tai; /* TAI offset (s) */
43static s64 time_offset; /* time adjustment (ns) */
44static long time_constant = 2; /* pll time constant */
45long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
46long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
47static s64 time_freq; /* frequency offset (scaled ns/s)*/
48static long time_reftime; /* time at last adjustment (s) */
49long time_adjust;
50static long ntp_tick_adj;
51 40
41/*
42 * clock synchronization status
43 *
44 * (TIME_ERROR prevents overwriting the CMOS clock)
45 */
46static int time_state = TIME_OK;
47
48/* clock status bits: */
49int time_status = STA_UNSYNC;
50
51/* TAI offset (secs): */
52static long time_tai;
53
54/* time adjustment (nsecs): */
55static s64 time_offset;
56
57/* pll time constant: */
58static long time_constant = 2;
59
60/* maximum error (usecs): */
61long time_maxerror = NTP_PHASE_LIMIT;
62
63/* estimated error (usecs): */
64long time_esterror = NTP_PHASE_LIMIT;
65
66/* frequency offset (scaled nsecs/secs): */
67static s64 time_freq;
68
69/* time at last adjustment (secs): */
70static long time_reftime;
71
72long time_adjust;
73
74/* constant (boot-param configurable) NTP tick adjustment (upscaled) */
75static s64 ntp_tick_adj;
76
77/*
78 * NTP methods:
79 */
80
81/*
82 * Update (tick_length, tick_length_base, tick_nsec), based
83 * on (tick_usec, ntp_tick_adj, time_freq):
84 */
52static void ntp_update_frequency(void) 85static void ntp_update_frequency(void)
53{ 86{
54 u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ) 87 u64 second_length;
55 << NTP_SCALE_SHIFT; 88 u64 new_base;
56 second_length += (s64)ntp_tick_adj << NTP_SCALE_SHIFT; 89
57 second_length += time_freq; 90 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
91 << NTP_SCALE_SHIFT;
92
93 second_length += ntp_tick_adj;
94 second_length += time_freq;
58 95
59 tick_length_base = second_length; 96 tick_nsec = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
97 new_base = div_u64(second_length, NTP_INTERVAL_FREQ);
60 98
61 tick_nsec = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT; 99 /*
62 tick_length_base = div_u64(tick_length_base, NTP_INTERVAL_FREQ); 100 * Don't wait for the next second_overflow, apply
101 * the change to the tick length immediately:
102 */
103 tick_length += new_base - tick_length_base;
104 tick_length_base = new_base;
105}
106
107static inline s64 ntp_update_offset_fll(s64 offset64, long secs)
108{
109 time_status &= ~STA_MODE;
110
111 if (secs < MINSEC)
112 return 0;
113
114 if (!(time_status & STA_FLL) && (secs <= MAXSEC))
115 return 0;
116
117 time_status |= STA_MODE;
118
119 return div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
63} 120}
64 121
65static void ntp_update_offset(long offset) 122static void ntp_update_offset(long offset)
66{ 123{
67 long mtemp;
68 s64 freq_adj; 124 s64 freq_adj;
125 s64 offset64;
126 long secs;
69 127
70 if (!(time_status & STA_PLL)) 128 if (!(time_status & STA_PLL))
71 return; 129 return;
@@ -84,24 +142,23 @@ static void ntp_update_offset(long offset)
84 * Select how the frequency is to be controlled 142 * Select how the frequency is to be controlled
85 * and in which mode (PLL or FLL). 143 * and in which mode (PLL or FLL).
86 */ 144 */
87 if (time_status & STA_FREQHOLD || time_reftime == 0) 145 secs = xtime.tv_sec - time_reftime;
88 time_reftime = xtime.tv_sec; 146 if (unlikely(time_status & STA_FREQHOLD))
89 mtemp = xtime.tv_sec - time_reftime; 147 secs = 0;
148
90 time_reftime = xtime.tv_sec; 149 time_reftime = xtime.tv_sec;
91 150
92 freq_adj = (s64)offset * mtemp; 151 offset64 = offset;
93 freq_adj <<= NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant); 152 freq_adj = (offset64 * secs) <<
94 time_status &= ~STA_MODE; 153 (NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant));
95 if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
96 freq_adj += div_s64((s64)offset << (NTP_SCALE_SHIFT - SHIFT_FLL),
97 mtemp);
98 time_status |= STA_MODE;
99 }
100 freq_adj += time_freq;
101 freq_adj = min(freq_adj, MAXFREQ_SCALED);
102 time_freq = max(freq_adj, -MAXFREQ_SCALED);
103 154
104 time_offset = div_s64((s64)offset << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ); 155 freq_adj += ntp_update_offset_fll(offset64, secs);
156
157 freq_adj = min(freq_adj + time_freq, MAXFREQ_SCALED);
158
159 time_freq = max(freq_adj, -MAXFREQ_SCALED);
160
161 time_offset = div_s64(offset64 << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);
105} 162}
106 163
107/** 164/**
@@ -111,15 +168,15 @@ static void ntp_update_offset(long offset)
111 */ 168 */
112void ntp_clear(void) 169void ntp_clear(void)
113{ 170{
114 time_adjust = 0; /* stop active adjtime() */ 171 time_adjust = 0; /* stop active adjtime() */
115 time_status |= STA_UNSYNC; 172 time_status |= STA_UNSYNC;
116 time_maxerror = NTP_PHASE_LIMIT; 173 time_maxerror = NTP_PHASE_LIMIT;
117 time_esterror = NTP_PHASE_LIMIT; 174 time_esterror = NTP_PHASE_LIMIT;
118 175
119 ntp_update_frequency(); 176 ntp_update_frequency();
120 177
121 tick_length = tick_length_base; 178 tick_length = tick_length_base;
122 time_offset = 0; 179 time_offset = 0;
123} 180}
124 181
125/* 182/*
@@ -140,8 +197,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
140 xtime.tv_sec--; 197 xtime.tv_sec--;
141 wall_to_monotonic.tv_sec++; 198 wall_to_monotonic.tv_sec++;
142 time_state = TIME_OOP; 199 time_state = TIME_OOP;
143 printk(KERN_NOTICE "Clock: " 200 printk(KERN_NOTICE
144 "inserting leap second 23:59:60 UTC\n"); 201 "Clock: inserting leap second 23:59:60 UTC\n");
145 hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC); 202 hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC);
146 res = HRTIMER_RESTART; 203 res = HRTIMER_RESTART;
147 break; 204 break;
@@ -150,8 +207,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
150 time_tai--; 207 time_tai--;
151 wall_to_monotonic.tv_sec--; 208 wall_to_monotonic.tv_sec--;
152 time_state = TIME_WAIT; 209 time_state = TIME_WAIT;
153 printk(KERN_NOTICE "Clock: " 210 printk(KERN_NOTICE
154 "deleting leap second 23:59:59 UTC\n"); 211 "Clock: deleting leap second 23:59:59 UTC\n");
155 break; 212 break;
156 case TIME_OOP: 213 case TIME_OOP:
157 time_tai++; 214 time_tai++;
@@ -179,7 +236,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
179 */ 236 */
180void second_overflow(void) 237void second_overflow(void)
181{ 238{
182 s64 time_adj; 239 s64 delta;
183 240
184 /* Bump the maxerror field */ 241 /* Bump the maxerror field */
185 time_maxerror += MAXFREQ / NSEC_PER_USEC; 242 time_maxerror += MAXFREQ / NSEC_PER_USEC;
@@ -192,24 +249,30 @@ void second_overflow(void)
192 * Compute the phase adjustment for the next second. The offset is 249 * Compute the phase adjustment for the next second. The offset is
193 * reduced by a fixed factor times the time constant. 250 * reduced by a fixed factor times the time constant.
194 */ 251 */
195 tick_length = tick_length_base; 252 tick_length = tick_length_base;
196 time_adj = shift_right(time_offset, SHIFT_PLL + time_constant); 253
197 time_offset -= time_adj; 254 delta = shift_right(time_offset, SHIFT_PLL + time_constant);
198 tick_length += time_adj; 255 time_offset -= delta;
199 256 tick_length += delta;
200 if (unlikely(time_adjust)) { 257
201 if (time_adjust > MAX_TICKADJ) { 258 if (!time_adjust)
202 time_adjust -= MAX_TICKADJ; 259 return;
203 tick_length += MAX_TICKADJ_SCALED; 260
204 } else if (time_adjust < -MAX_TICKADJ) { 261 if (time_adjust > MAX_TICKADJ) {
205 time_adjust += MAX_TICKADJ; 262 time_adjust -= MAX_TICKADJ;
206 tick_length -= MAX_TICKADJ_SCALED; 263 tick_length += MAX_TICKADJ_SCALED;
207 } else { 264 return;
208 tick_length += (s64)(time_adjust * NSEC_PER_USEC /
209 NTP_INTERVAL_FREQ) << NTP_SCALE_SHIFT;
210 time_adjust = 0;
211 }
212 } 265 }
266
267 if (time_adjust < -MAX_TICKADJ) {
268 time_adjust += MAX_TICKADJ;
269 tick_length -= MAX_TICKADJ_SCALED;
270 return;
271 }
272
273 tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
274 << NTP_SCALE_SHIFT;
275 time_adjust = 0;
213} 276}
214 277
215#ifdef CONFIG_GENERIC_CMOS_UPDATE 278#ifdef CONFIG_GENERIC_CMOS_UPDATE
@@ -233,12 +296,13 @@ static void sync_cmos_clock(struct work_struct *work)
233 * This code is run on a timer. If the clock is set, that timer 296 * This code is run on a timer. If the clock is set, that timer
234 * may not expire at the correct time. Thus, we adjust... 297 * may not expire at the correct time. Thus, we adjust...
235 */ 298 */
236 if (!ntp_synced()) 299 if (!ntp_synced()) {
237 /* 300 /*
238 * Not synced, exit, do not restart a timer (if one is 301 * Not synced, exit, do not restart a timer (if one is
239 * running, let it run out). 302 * running, let it run out).
240 */ 303 */
241 return; 304 return;
305 }
242 306
243 getnstimeofday(&now); 307 getnstimeofday(&now);
244 if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) 308 if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
@@ -270,7 +334,116 @@ static void notify_cmos_timer(void)
270static inline void notify_cmos_timer(void) { } 334static inline void notify_cmos_timer(void) { }
271#endif 335#endif
272 336
273/* adjtimex mainly allows reading (and writing, if superuser) of 337/*
338 * Start the leap seconds timer:
339 */
340static inline void ntp_start_leap_timer(struct timespec *ts)
341{
342 long now = ts->tv_sec;
343
344 if (time_status & STA_INS) {
345 time_state = TIME_INS;
346 now += 86400 - now % 86400;
347 hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
348
349 return;
350 }
351
352 if (time_status & STA_DEL) {
353 time_state = TIME_DEL;
354 now += 86400 - (now + 1) % 86400;
355 hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
356 }
357}
358
359/*
360 * Propagate a new txc->status value into the NTP state:
361 */
362static inline void process_adj_status(struct timex *txc, struct timespec *ts)
363{
364 if ((time_status & STA_PLL) && !(txc->status & STA_PLL)) {
365 time_state = TIME_OK;
366 time_status = STA_UNSYNC;
367 }
368
369 /*
370 * If we turn on PLL adjustments then reset the
371 * reference time to current time.
372 */
373 if (!(time_status & STA_PLL) && (txc->status & STA_PLL))
374 time_reftime = xtime.tv_sec;
375
376 /* only set allowed bits */
377 time_status &= STA_RONLY;
378 time_status |= txc->status & ~STA_RONLY;
379
380 switch (time_state) {
381 case TIME_OK:
382 ntp_start_leap_timer(ts);
383 break;
384 case TIME_INS:
385 case TIME_DEL:
386 time_state = TIME_OK;
387 ntp_start_leap_timer(ts);
388 case TIME_WAIT:
389 if (!(time_status & (STA_INS | STA_DEL)))
390 time_state = TIME_OK;
391 break;
392 case TIME_OOP:
393 hrtimer_restart(&leap_timer);
394 break;
395 }
396}
397/*
398 * Called with the xtime lock held, so we can access and modify
399 * all the global NTP state:
400 */
401static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts)
402{
403 if (txc->modes & ADJ_STATUS)
404 process_adj_status(txc, ts);
405
406 if (txc->modes & ADJ_NANO)
407 time_status |= STA_NANO;
408
409 if (txc->modes & ADJ_MICRO)
410 time_status &= ~STA_NANO;
411
412 if (txc->modes & ADJ_FREQUENCY) {
413 time_freq = txc->freq * PPM_SCALE;
414 time_freq = min(time_freq, MAXFREQ_SCALED);
415 time_freq = max(time_freq, -MAXFREQ_SCALED);
416 }
417
418 if (txc->modes & ADJ_MAXERROR)
419 time_maxerror = txc->maxerror;
420
421 if (txc->modes & ADJ_ESTERROR)
422 time_esterror = txc->esterror;
423
424 if (txc->modes & ADJ_TIMECONST) {
425 time_constant = txc->constant;
426 if (!(time_status & STA_NANO))
427 time_constant += 4;
428 time_constant = min(time_constant, (long)MAXTC);
429 time_constant = max(time_constant, 0l);
430 }
431
432 if (txc->modes & ADJ_TAI && txc->constant > 0)
433 time_tai = txc->constant;
434
435 if (txc->modes & ADJ_OFFSET)
436 ntp_update_offset(txc->offset);
437
438 if (txc->modes & ADJ_TICK)
439 tick_usec = txc->tick;
440
441 if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
442 ntp_update_frequency();
443}
444
445/*
446 * adjtimex mainly allows reading (and writing, if superuser) of
274 * kernel time-keeping variables. used by xntpd. 447 * kernel time-keeping variables. used by xntpd.
275 */ 448 */
276int do_adjtimex(struct timex *txc) 449int do_adjtimex(struct timex *txc)
@@ -291,11 +464,14 @@ int do_adjtimex(struct timex *txc)
291 if (txc->modes && !capable(CAP_SYS_TIME)) 464 if (txc->modes && !capable(CAP_SYS_TIME))
292 return -EPERM; 465 return -EPERM;
293 466
294 /* if the quartz is off by more than 10% something is VERY wrong! */ 467 /*
468 * if the quartz is off by more than 10% then
469 * something is VERY wrong!
470 */
295 if (txc->modes & ADJ_TICK && 471 if (txc->modes & ADJ_TICK &&
296 (txc->tick < 900000/USER_HZ || 472 (txc->tick < 900000/USER_HZ ||
297 txc->tick > 1100000/USER_HZ)) 473 txc->tick > 1100000/USER_HZ))
298 return -EINVAL; 474 return -EINVAL;
299 475
300 if (txc->modes & ADJ_STATUS && time_state != TIME_OK) 476 if (txc->modes & ADJ_STATUS && time_state != TIME_OK)
301 hrtimer_cancel(&leap_timer); 477 hrtimer_cancel(&leap_timer);
@@ -305,7 +481,6 @@ int do_adjtimex(struct timex *txc)
305 481
306 write_seqlock_irq(&xtime_lock); 482 write_seqlock_irq(&xtime_lock);
307 483
308 /* If there are input parameters, then process them */
309 if (txc->modes & ADJ_ADJTIME) { 484 if (txc->modes & ADJ_ADJTIME) {
310 long save_adjust = time_adjust; 485 long save_adjust = time_adjust;
311 486
@@ -315,98 +490,24 @@ int do_adjtimex(struct timex *txc)
315 ntp_update_frequency(); 490 ntp_update_frequency();
316 } 491 }
317 txc->offset = save_adjust; 492 txc->offset = save_adjust;
318 goto adj_done; 493 } else {
319 }
320 if (txc->modes) {
321 long sec;
322
323 if (txc->modes & ADJ_STATUS) {
324 if ((time_status & STA_PLL) &&
325 !(txc->status & STA_PLL)) {
326 time_state = TIME_OK;
327 time_status = STA_UNSYNC;
328 }
329 /* only set allowed bits */
330 time_status &= STA_RONLY;
331 time_status |= txc->status & ~STA_RONLY;
332
333 switch (time_state) {
334 case TIME_OK:
335 start_timer:
336 sec = ts.tv_sec;
337 if (time_status & STA_INS) {
338 time_state = TIME_INS;
339 sec += 86400 - sec % 86400;
340 hrtimer_start(&leap_timer, ktime_set(sec, 0), HRTIMER_MODE_ABS);
341 } else if (time_status & STA_DEL) {
342 time_state = TIME_DEL;
343 sec += 86400 - (sec + 1) % 86400;
344 hrtimer_start(&leap_timer, ktime_set(sec, 0), HRTIMER_MODE_ABS);
345 }
346 break;
347 case TIME_INS:
348 case TIME_DEL:
349 time_state = TIME_OK;
350 goto start_timer;
351 break;
352 case TIME_WAIT:
353 if (!(time_status & (STA_INS | STA_DEL)))
354 time_state = TIME_OK;
355 break;
356 case TIME_OOP:
357 hrtimer_restart(&leap_timer);
358 break;
359 }
360 }
361
362 if (txc->modes & ADJ_NANO)
363 time_status |= STA_NANO;
364 if (txc->modes & ADJ_MICRO)
365 time_status &= ~STA_NANO;
366
367 if (txc->modes & ADJ_FREQUENCY) {
368 time_freq = (s64)txc->freq * PPM_SCALE;
369 time_freq = min(time_freq, MAXFREQ_SCALED);
370 time_freq = max(time_freq, -MAXFREQ_SCALED);
371 }
372
373 if (txc->modes & ADJ_MAXERROR)
374 time_maxerror = txc->maxerror;
375 if (txc->modes & ADJ_ESTERROR)
376 time_esterror = txc->esterror;
377
378 if (txc->modes & ADJ_TIMECONST) {
379 time_constant = txc->constant;
380 if (!(time_status & STA_NANO))
381 time_constant += 4;
382 time_constant = min(time_constant, (long)MAXTC);
383 time_constant = max(time_constant, 0l);
384 }
385
386 if (txc->modes & ADJ_TAI && txc->constant > 0)
387 time_tai = txc->constant;
388
389 if (txc->modes & ADJ_OFFSET)
390 ntp_update_offset(txc->offset);
391 if (txc->modes & ADJ_TICK)
392 tick_usec = txc->tick;
393 494
394 if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET)) 495 /* If there are input parameters, then process them: */
395 ntp_update_frequency(); 496 if (txc->modes)
396 } 497 process_adjtimex_modes(txc, &ts);
397 498
398 txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ, 499 txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
399 NTP_SCALE_SHIFT); 500 NTP_SCALE_SHIFT);
400 if (!(time_status & STA_NANO)) 501 if (!(time_status & STA_NANO))
401 txc->offset /= NSEC_PER_USEC; 502 txc->offset /= NSEC_PER_USEC;
503 }
402 504
403adj_done:
404 result = time_state; /* mostly `TIME_OK' */ 505 result = time_state; /* mostly `TIME_OK' */
405 if (time_status & (STA_UNSYNC|STA_CLOCKERR)) 506 if (time_status & (STA_UNSYNC|STA_CLOCKERR))
406 result = TIME_ERROR; 507 result = TIME_ERROR;
407 508
408 txc->freq = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) * 509 txc->freq = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) *
409 (s64)PPM_SCALE_INV, NTP_SCALE_SHIFT); 510 PPM_SCALE_INV, NTP_SCALE_SHIFT);
410 txc->maxerror = time_maxerror; 511 txc->maxerror = time_maxerror;
411 txc->esterror = time_esterror; 512 txc->esterror = time_esterror;
412 txc->status = time_status; 513 txc->status = time_status;
@@ -425,6 +526,7 @@ adj_done:
425 txc->calcnt = 0; 526 txc->calcnt = 0;
426 txc->errcnt = 0; 527 txc->errcnt = 0;
427 txc->stbcnt = 0; 528 txc->stbcnt = 0;
529
428 write_sequnlock_irq(&xtime_lock); 530 write_sequnlock_irq(&xtime_lock);
429 531
430 txc->time.tv_sec = ts.tv_sec; 532 txc->time.tv_sec = ts.tv_sec;
@@ -440,6 +542,8 @@ adj_done:
440static int __init ntp_tick_adj_setup(char *str) 542static int __init ntp_tick_adj_setup(char *str)
441{ 543{
442 ntp_tick_adj = simple_strtol(str, NULL, 0); 544 ntp_tick_adj = simple_strtol(str, NULL, 0);
545 ntp_tick_adj <<= NTP_SCALE_SHIFT;
546
443 return 1; 547 return 1;
444} 548}
445 549
diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c
new file mode 100644
index 000000000000..71e7f1a19156
--- /dev/null
+++ b/kernel/time/timecompare.c
@@ -0,0 +1,191 @@
1/*
2 * Copyright (C) 2009 Intel Corporation.
3 * Author: Patrick Ohly <patrick.ohly@intel.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19
20#include <linux/timecompare.h>
21#include <linux/module.h>
22#include <linux/math64.h>
23
24/*
25 * fixed point arithmetic scale factor for skew
26 *
27 * Usually one would measure skew in ppb (parts per billion, 1e9), but
28 * using a factor of 2 simplifies the math.
29 */
30#define TIMECOMPARE_SKEW_RESOLUTION (((s64)1)<<30)
31
32ktime_t timecompare_transform(struct timecompare *sync,
33 u64 source_tstamp)
34{
35 u64 nsec;
36
37 nsec = source_tstamp + sync->offset;
38 nsec += (s64)(source_tstamp - sync->last_update) * sync->skew /
39 TIMECOMPARE_SKEW_RESOLUTION;
40
41 return ns_to_ktime(nsec);
42}
43EXPORT_SYMBOL(timecompare_transform);
44
45int timecompare_offset(struct timecompare *sync,
46 s64 *offset,
47 u64 *source_tstamp)
48{
49 u64 start_source = 0, end_source = 0;
50 struct {
51 s64 offset;
52 s64 duration_target;
53 } buffer[10], sample, *samples;
54 int counter = 0, i;
55 int used;
56 int index;
57 int num_samples = sync->num_samples;
58
59 if (num_samples > sizeof(buffer)/sizeof(buffer[0])) {
60 samples = kmalloc(sizeof(*samples) * num_samples, GFP_ATOMIC);
61 if (!samples) {
62 samples = buffer;
63 num_samples = sizeof(buffer)/sizeof(buffer[0]);
64 }
65 } else {
66 samples = buffer;
67 }
68
69 /* run until we have enough valid samples, but do not try forever */
70 i = 0;
71 counter = 0;
72 while (1) {
73 u64 ts;
74 ktime_t start, end;
75
76 start = sync->target();
77 ts = timecounter_read(sync->source);
78 end = sync->target();
79
80 if (!i)
81 start_source = ts;
82
83 /* ignore negative durations */
84 sample.duration_target = ktime_to_ns(ktime_sub(end, start));
85 if (sample.duration_target >= 0) {
86 /*
87 * assume symetric delay to and from source:
88 * average target time corresponds to measured
89 * source time
90 */
91 sample.offset =
92 ktime_to_ns(ktime_add(end, start)) / 2 -
93 ts;
94
95 /* simple insertion sort based on duration */
96 index = counter - 1;
97 while (index >= 0) {
98 if (samples[index].duration_target <
99 sample.duration_target)
100 break;
101 samples[index + 1] = samples[index];
102 index--;
103 }
104 samples[index + 1] = sample;
105 counter++;
106 }
107
108 i++;
109 if (counter >= num_samples || i >= 100000) {
110 end_source = ts;
111 break;
112 }
113 }
114
115 *source_tstamp = (end_source + start_source) / 2;
116
117 /* remove outliers by only using 75% of the samples */
118 used = counter * 3 / 4;
119 if (!used)
120 used = counter;
121 if (used) {
122 /* calculate average */
123 s64 off = 0;
124 for (index = 0; index < used; index++)
125 off += samples[index].offset;
126 *offset = div_s64(off, used);
127 }
128
129 if (samples && samples != buffer)
130 kfree(samples);
131
132 return used;
133}
134EXPORT_SYMBOL(timecompare_offset);
135
136void __timecompare_update(struct timecompare *sync,
137 u64 source_tstamp)
138{
139 s64 offset;
140 u64 average_time;
141
142 if (!timecompare_offset(sync, &offset, &average_time))
143 return;
144
145 if (!sync->last_update) {
146 sync->last_update = average_time;
147 sync->offset = offset;
148 sync->skew = 0;
149 } else {
150 s64 delta_nsec = average_time - sync->last_update;
151
152 /* avoid division by negative or small deltas */
153 if (delta_nsec >= 10000) {
154 s64 delta_offset_nsec = offset - sync->offset;
155 s64 skew; /* delta_offset_nsec *
156 TIMECOMPARE_SKEW_RESOLUTION /
157 delta_nsec */
158 u64 divisor;
159
160 /* div_s64() is limited to 32 bit divisor */
161 skew = delta_offset_nsec * TIMECOMPARE_SKEW_RESOLUTION;
162 divisor = delta_nsec;
163 while (unlikely(divisor >= ((s64)1) << 32)) {
164 /* divide both by 2; beware, right shift
165 of negative value has undefined
166 behavior and can only be used for
167 the positive divisor */
168 skew = div_s64(skew, 2);
169 divisor >>= 1;
170 }
171 skew = div_s64(skew, divisor);
172
173 /*
174 * Calculate new overall skew as 4/16 the
175 * old value and 12/16 the new one. This is
176 * a rather arbitrary tradeoff between
177 * only using the latest measurement (0/16 and
178 * 16/16) and even more weight on past measurements.
179 */
180#define TIMECOMPARE_NEW_SKEW_PER_16 12
181 sync->skew =
182 div_s64((16 - TIMECOMPARE_NEW_SKEW_PER_16) *
183 sync->skew +
184 TIMECOMPARE_NEW_SKEW_PER_16 * skew,
185 16);
186 sync->last_update = average_time;
187 sync->offset = offset;
188 }
189 }
190}
191EXPORT_SYMBOL(__timecompare_update);
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