2006-10-01 08:28:22 +02:00
|
|
|
/*
|
|
|
|
* linux/kernel/time/ntp.c
|
|
|
|
*
|
|
|
|
* NTP state machine interfaces and logic.
|
|
|
|
*
|
|
|
|
* This code was mainly moved from kernel/timer.c and kernel/time.c
|
|
|
|
* Please see those files for relevant copyright info and historical
|
|
|
|
* changelogs.
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include <linux/mm.h>
|
|
|
|
#include <linux/time.h>
|
|
|
|
#include <linux/timex.h>
|
Detach sched.h from mm.h
First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.
This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
getting them indirectly
Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
they don't need sched.h
b) sched.h stops being dependency for significant number of files:
on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
after patch it's only 3744 (-8.3%).
Cross-compile tested on
all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
alpha alpha-up
arm
i386 i386-up i386-defconfig i386-allnoconfig
ia64 ia64-up
m68k
mips
parisc parisc-up
powerpc powerpc-up
s390 s390-up
sparc sparc-up
sparc64 sparc64-up
um-x86_64
x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig
as well as my two usual configs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-20 23:22:52 +02:00
|
|
|
#include <linux/jiffies.h>
|
|
|
|
#include <linux/hrtimer.h>
|
2006-10-01 08:28:22 +02:00
|
|
|
|
|
|
|
#include <asm/div64.h>
|
|
|
|
#include <asm/timex.h>
|
|
|
|
|
2006-10-01 08:28:22 +02:00
|
|
|
/*
|
|
|
|
* Timekeeping variables
|
|
|
|
*/
|
|
|
|
unsigned long tick_usec = TICK_USEC; /* USER_HZ period (usec) */
|
|
|
|
unsigned long tick_nsec; /* ACTHZ period (nsec) */
|
|
|
|
static u64 tick_length, tick_length_base;
|
|
|
|
|
2006-10-01 08:28:25 +02:00
|
|
|
#define MAX_TICKADJ 500 /* microsecs */
|
|
|
|
#define MAX_TICKADJ_SCALED (((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \
|
2007-02-16 10:27:26 +01:00
|
|
|
TICK_LENGTH_SHIFT) / NTP_INTERVAL_FREQ)
|
2006-10-01 08:28:22 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* phase-lock loop variables
|
|
|
|
*/
|
|
|
|
/* TIME_ERROR prevents overwriting the CMOS clock */
|
2006-10-01 08:28:29 +02:00
|
|
|
static int time_state = TIME_OK; /* clock synchronization status */
|
2006-10-01 08:28:22 +02:00
|
|
|
int time_status = STA_UNSYNC; /* clock status bits */
|
2007-03-27 07:32:26 +02:00
|
|
|
static s64 time_offset; /* time adjustment (ns) */
|
2006-10-01 08:28:29 +02:00
|
|
|
static long time_constant = 2; /* pll time constant */
|
2006-10-01 08:28:22 +02:00
|
|
|
long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
|
|
|
|
long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
|
2006-10-01 08:28:24 +02:00
|
|
|
long time_freq; /* frequency offset (scaled ppm)*/
|
2006-10-01 08:28:29 +02:00
|
|
|
static long time_reftime; /* time at last adjustment (s) */
|
2006-10-01 08:28:22 +02:00
|
|
|
long time_adjust;
|
|
|
|
|
2006-10-01 08:28:29 +02:00
|
|
|
#define CLOCK_TICK_OVERFLOW (LATCH * HZ - CLOCK_TICK_RATE)
|
|
|
|
#define CLOCK_TICK_ADJUST (((s64)CLOCK_TICK_OVERFLOW * NSEC_PER_SEC) / \
|
|
|
|
(s64)CLOCK_TICK_RATE)
|
|
|
|
|
|
|
|
static void ntp_update_frequency(void)
|
|
|
|
{
|
2007-02-16 10:27:26 +01:00
|
|
|
u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
|
|
|
|
<< TICK_LENGTH_SHIFT;
|
|
|
|
second_length += (s64)CLOCK_TICK_ADJUST << TICK_LENGTH_SHIFT;
|
|
|
|
second_length += (s64)time_freq << (TICK_LENGTH_SHIFT - SHIFT_NSEC);
|
2006-10-01 08:28:29 +02:00
|
|
|
|
2007-02-16 10:27:26 +01:00
|
|
|
tick_length_base = second_length;
|
2006-10-01 08:28:29 +02:00
|
|
|
|
2007-02-16 10:27:26 +01:00
|
|
|
do_div(second_length, HZ);
|
|
|
|
tick_nsec = second_length >> TICK_LENGTH_SHIFT;
|
|
|
|
|
|
|
|
do_div(tick_length_base, NTP_INTERVAL_FREQ);
|
2006-10-01 08:28:29 +02:00
|
|
|
}
|
|
|
|
|
2006-10-01 08:28:22 +02:00
|
|
|
/**
|
|
|
|
* ntp_clear - Clears the NTP state variables
|
|
|
|
*
|
|
|
|
* Must be called while holding a write on the xtime_lock
|
|
|
|
*/
|
|
|
|
void ntp_clear(void)
|
|
|
|
{
|
|
|
|
time_adjust = 0; /* stop active adjtime() */
|
|
|
|
time_status |= STA_UNSYNC;
|
|
|
|
time_maxerror = NTP_PHASE_LIMIT;
|
|
|
|
time_esterror = NTP_PHASE_LIMIT;
|
|
|
|
|
|
|
|
ntp_update_frequency();
|
|
|
|
|
|
|
|
tick_length = tick_length_base;
|
2006-10-01 08:28:25 +02:00
|
|
|
time_offset = 0;
|
2006-10-01 08:28:22 +02:00
|
|
|
}
|
|
|
|
|
2006-10-01 08:28:22 +02:00
|
|
|
/*
|
|
|
|
* this routine handles the overflow of the microsecond field
|
|
|
|
*
|
|
|
|
* The tricky bits of code to handle the accurate clock support
|
|
|
|
* were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
|
|
|
|
* They were originally developed for SUN and DEC kernels.
|
|
|
|
* All the kudos should go to Dave for this stuff.
|
|
|
|
*/
|
|
|
|
void second_overflow(void)
|
|
|
|
{
|
2006-10-01 08:28:25 +02:00
|
|
|
long time_adj;
|
2006-10-01 08:28:22 +02:00
|
|
|
|
|
|
|
/* Bump the maxerror field */
|
2006-10-01 08:28:26 +02:00
|
|
|
time_maxerror += MAXFREQ >> SHIFT_USEC;
|
2006-10-01 08:28:22 +02:00
|
|
|
if (time_maxerror > NTP_PHASE_LIMIT) {
|
|
|
|
time_maxerror = NTP_PHASE_LIMIT;
|
|
|
|
time_status |= STA_UNSYNC;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Leap second processing. If in leap-insert state at the end of the
|
|
|
|
* day, the system clock is set back one second; if in leap-delete
|
|
|
|
* state, the system clock is set ahead one second. The microtime()
|
|
|
|
* routine or external clock driver will insure that reported time is
|
|
|
|
* always monotonic. The ugly divides should be replaced.
|
|
|
|
*/
|
|
|
|
switch (time_state) {
|
|
|
|
case TIME_OK:
|
|
|
|
if (time_status & STA_INS)
|
|
|
|
time_state = TIME_INS;
|
|
|
|
else if (time_status & STA_DEL)
|
|
|
|
time_state = TIME_DEL;
|
|
|
|
break;
|
|
|
|
case TIME_INS:
|
|
|
|
if (xtime.tv_sec % 86400 == 0) {
|
|
|
|
xtime.tv_sec--;
|
|
|
|
wall_to_monotonic.tv_sec++;
|
|
|
|
/*
|
|
|
|
* The timer interpolator will make time change
|
|
|
|
* gradually instead of an immediate jump by one second
|
|
|
|
*/
|
|
|
|
time_interpolator_update(-NSEC_PER_SEC);
|
|
|
|
time_state = TIME_OOP;
|
|
|
|
printk(KERN_NOTICE "Clock: inserting leap second "
|
|
|
|
"23:59:60 UTC\n");
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
case TIME_DEL:
|
|
|
|
if ((xtime.tv_sec + 1) % 86400 == 0) {
|
|
|
|
xtime.tv_sec++;
|
|
|
|
wall_to_monotonic.tv_sec--;
|
|
|
|
/*
|
|
|
|
* Use of time interpolator for a gradual change of
|
|
|
|
* time
|
|
|
|
*/
|
|
|
|
time_interpolator_update(NSEC_PER_SEC);
|
|
|
|
time_state = TIME_WAIT;
|
|
|
|
printk(KERN_NOTICE "Clock: deleting leap second "
|
|
|
|
"23:59:59 UTC\n");
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
case TIME_OOP:
|
|
|
|
time_state = TIME_WAIT;
|
|
|
|
break;
|
|
|
|
case TIME_WAIT:
|
|
|
|
if (!(time_status & (STA_INS | STA_DEL)))
|
|
|
|
time_state = TIME_OK;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2006-10-01 08:28:28 +02:00
|
|
|
* Compute the phase adjustment for the next second. The offset is
|
|
|
|
* reduced by a fixed factor times the time constant.
|
2006-10-01 08:28:22 +02:00
|
|
|
*/
|
2006-10-01 08:28:22 +02:00
|
|
|
tick_length = tick_length_base;
|
2006-10-01 08:28:28 +02:00
|
|
|
time_adj = shift_right(time_offset, SHIFT_PLL + time_constant);
|
2006-10-01 08:28:25 +02:00
|
|
|
time_offset -= time_adj;
|
|
|
|
tick_length += (s64)time_adj << (TICK_LENGTH_SHIFT - SHIFT_UPDATE);
|
2006-10-01 08:28:22 +02:00
|
|
|
|
2006-10-01 08:28:25 +02:00
|
|
|
if (unlikely(time_adjust)) {
|
|
|
|
if (time_adjust > MAX_TICKADJ) {
|
|
|
|
time_adjust -= MAX_TICKADJ;
|
|
|
|
tick_length += MAX_TICKADJ_SCALED;
|
|
|
|
} else if (time_adjust < -MAX_TICKADJ) {
|
|
|
|
time_adjust += MAX_TICKADJ;
|
|
|
|
tick_length -= MAX_TICKADJ_SCALED;
|
|
|
|
} else {
|
|
|
|
tick_length += (s64)(time_adjust * NSEC_PER_USEC /
|
2007-02-16 10:27:26 +01:00
|
|
|
NTP_INTERVAL_FREQ) << TICK_LENGTH_SHIFT;
|
2006-10-28 19:38:56 +02:00
|
|
|
time_adjust = 0;
|
2006-10-01 08:28:25 +02:00
|
|
|
}
|
2006-10-01 08:28:22 +02:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Return how long ticks are at the moment, that is, how much time
|
|
|
|
* update_wall_time_one_tick will add to xtime next time we call it
|
|
|
|
* (assuming no calls to do_adjtimex in the meantime).
|
|
|
|
* The return value is in fixed-point nanoseconds shifted by the
|
|
|
|
* specified number of bits to the right of the binary point.
|
|
|
|
* This function has no side-effects.
|
|
|
|
*/
|
|
|
|
u64 current_tick_length(void)
|
|
|
|
{
|
2006-10-01 08:28:25 +02:00
|
|
|
return tick_length;
|
2006-10-01 08:28:22 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
void __attribute__ ((weak)) notify_arch_cmos_timer(void)
|
|
|
|
{
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* adjtimex mainly allows reading (and writing, if superuser) of
|
|
|
|
* kernel time-keeping variables. used by xntpd.
|
|
|
|
*/
|
|
|
|
int do_adjtimex(struct timex *txc)
|
|
|
|
{
|
2007-03-27 07:32:26 +02:00
|
|
|
long mtemp, save_adjust, rem;
|
2006-10-01 08:28:28 +02:00
|
|
|
s64 freq_adj, temp64;
|
2006-10-01 08:28:22 +02:00
|
|
|
int result;
|
|
|
|
|
|
|
|
/* In order to modify anything, you gotta be super-user! */
|
|
|
|
if (txc->modes && !capable(CAP_SYS_TIME))
|
|
|
|
return -EPERM;
|
|
|
|
|
|
|
|
/* Now we validate the data before disabling interrupts */
|
|
|
|
|
|
|
|
if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
|
|
|
|
/* singleshot must not be used with any other mode bits */
|
|
|
|
if (txc->modes != ADJ_OFFSET_SINGLESHOT)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
if (txc->modes != ADJ_OFFSET_SINGLESHOT && (txc->modes & ADJ_OFFSET))
|
|
|
|
/* adjustment Offset limited to +- .512 seconds */
|
|
|
|
if (txc->offset <= - MAXPHASE || txc->offset >= MAXPHASE )
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
/* if the quartz is off by more than 10% something is VERY wrong ! */
|
|
|
|
if (txc->modes & ADJ_TICK)
|
|
|
|
if (txc->tick < 900000/USER_HZ ||
|
|
|
|
txc->tick > 1100000/USER_HZ)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
write_seqlock_irq(&xtime_lock);
|
|
|
|
result = time_state; /* mostly `TIME_OK' */
|
|
|
|
|
|
|
|
/* Save for later - semantics of adjtime is to return old value */
|
2006-10-01 08:28:25 +02:00
|
|
|
save_adjust = time_adjust;
|
2006-10-01 08:28:22 +02:00
|
|
|
|
|
|
|
#if 0 /* STA_CLOCKERR is never set yet */
|
|
|
|
time_status &= ~STA_CLOCKERR; /* reset STA_CLOCKERR */
|
|
|
|
#endif
|
|
|
|
/* If there are input parameters, then process them */
|
|
|
|
if (txc->modes)
|
|
|
|
{
|
|
|
|
if (txc->modes & ADJ_STATUS) /* only set allowed bits */
|
|
|
|
time_status = (txc->status & ~STA_RONLY) |
|
|
|
|
(time_status & STA_RONLY);
|
|
|
|
|
|
|
|
if (txc->modes & ADJ_FREQUENCY) { /* p. 22 */
|
|
|
|
if (txc->freq > MAXFREQ || txc->freq < -MAXFREQ) {
|
|
|
|
result = -EINVAL;
|
|
|
|
goto leave;
|
|
|
|
}
|
2007-02-16 10:27:26 +01:00
|
|
|
time_freq = ((s64)txc->freq * NSEC_PER_USEC)
|
|
|
|
>> (SHIFT_USEC - SHIFT_NSEC);
|
2006-10-01 08:28:22 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
if (txc->modes & ADJ_MAXERROR) {
|
|
|
|
if (txc->maxerror < 0 || txc->maxerror >= NTP_PHASE_LIMIT) {
|
|
|
|
result = -EINVAL;
|
|
|
|
goto leave;
|
|
|
|
}
|
|
|
|
time_maxerror = txc->maxerror;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (txc->modes & ADJ_ESTERROR) {
|
|
|
|
if (txc->esterror < 0 || txc->esterror >= NTP_PHASE_LIMIT) {
|
|
|
|
result = -EINVAL;
|
|
|
|
goto leave;
|
|
|
|
}
|
|
|
|
time_esterror = txc->esterror;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (txc->modes & ADJ_TIMECONST) { /* p. 24 */
|
|
|
|
if (txc->constant < 0) { /* NTP v4 uses values > 6 */
|
|
|
|
result = -EINVAL;
|
|
|
|
goto leave;
|
|
|
|
}
|
2006-10-01 08:28:28 +02:00
|
|
|
time_constant = min(txc->constant + 4, (long)MAXTC);
|
2006-10-01 08:28:22 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
if (txc->modes & ADJ_OFFSET) { /* values checked earlier */
|
|
|
|
if (txc->modes == ADJ_OFFSET_SINGLESHOT) {
|
|
|
|
/* adjtime() is independent from ntp_adjtime() */
|
2006-10-01 08:28:25 +02:00
|
|
|
time_adjust = txc->offset;
|
2006-10-01 08:28:22 +02:00
|
|
|
}
|
|
|
|
else if (time_status & STA_PLL) {
|
2007-03-27 07:32:26 +02:00
|
|
|
time_offset = txc->offset * NSEC_PER_USEC;
|
2006-10-01 08:28:22 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Scale the phase adjustment and
|
|
|
|
* clamp to the operating range.
|
|
|
|
*/
|
2007-03-27 07:32:26 +02:00
|
|
|
time_offset = min(time_offset, (s64)MAXPHASE * NSEC_PER_USEC);
|
|
|
|
time_offset = max(time_offset, (s64)-MAXPHASE * NSEC_PER_USEC);
|
2006-10-01 08:28:22 +02:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Select whether the frequency is to be controlled
|
|
|
|
* and in which mode (PLL or FLL). Clamp to the operating
|
|
|
|
* range. Ugly multiply/divide should be replaced someday.
|
|
|
|
*/
|
|
|
|
|
|
|
|
if (time_status & STA_FREQHOLD || time_reftime == 0)
|
|
|
|
time_reftime = xtime.tv_sec;
|
|
|
|
mtemp = xtime.tv_sec - time_reftime;
|
|
|
|
time_reftime = xtime.tv_sec;
|
2006-10-01 08:28:28 +02:00
|
|
|
|
2007-03-27 07:32:26 +02:00
|
|
|
freq_adj = time_offset * mtemp;
|
2006-10-01 08:28:28 +02:00
|
|
|
freq_adj = shift_right(freq_adj, time_constant * 2 +
|
|
|
|
(SHIFT_PLL + 2) * 2 - SHIFT_NSEC);
|
|
|
|
if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
|
2007-03-27 07:32:26 +02:00
|
|
|
temp64 = time_offset << (SHIFT_NSEC - SHIFT_FLL);
|
2006-10-01 08:28:28 +02:00
|
|
|
if (time_offset < 0) {
|
|
|
|
temp64 = -temp64;
|
|
|
|
do_div(temp64, mtemp);
|
|
|
|
freq_adj -= temp64;
|
|
|
|
} else {
|
|
|
|
do_div(temp64, mtemp);
|
|
|
|
freq_adj += temp64;
|
|
|
|
}
|
2006-10-01 08:28:22 +02:00
|
|
|
}
|
2006-10-01 08:28:27 +02:00
|
|
|
freq_adj += time_freq;
|
|
|
|
freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC);
|
|
|
|
time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC);
|
2007-03-27 07:32:26 +02:00
|
|
|
time_offset = div_long_long_rem_signed(time_offset,
|
|
|
|
NTP_INTERVAL_FREQ,
|
|
|
|
&rem);
|
|
|
|
time_offset <<= SHIFT_UPDATE;
|
2006-10-01 08:28:22 +02:00
|
|
|
} /* STA_PLL */
|
|
|
|
} /* txc->modes & ADJ_OFFSET */
|
2006-10-01 08:28:22 +02:00
|
|
|
if (txc->modes & ADJ_TICK)
|
2006-10-01 08:28:22 +02:00
|
|
|
tick_usec = txc->tick;
|
2006-10-01 08:28:22 +02:00
|
|
|
|
2006-10-01 08:28:24 +02:00
|
|
|
if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
|
2006-10-01 08:28:22 +02:00
|
|
|
ntp_update_frequency();
|
2006-10-01 08:28:22 +02:00
|
|
|
} /* txc->modes */
|
|
|
|
leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0)
|
|
|
|
result = TIME_ERROR;
|
|
|
|
|
|
|
|
if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
|
2007-03-27 07:32:26 +02:00
|
|
|
txc->offset = save_adjust;
|
2006-10-01 08:28:25 +02:00
|
|
|
else
|
2007-03-27 07:32:26 +02:00
|
|
|
txc->offset = ((long)shift_right(time_offset, SHIFT_UPDATE)) *
|
|
|
|
NTP_INTERVAL_FREQ / 1000;
|
|
|
|
txc->freq = (time_freq / NSEC_PER_USEC) <<
|
|
|
|
(SHIFT_USEC - SHIFT_NSEC);
|
2006-10-01 08:28:22 +02:00
|
|
|
txc->maxerror = time_maxerror;
|
|
|
|
txc->esterror = time_esterror;
|
|
|
|
txc->status = time_status;
|
|
|
|
txc->constant = time_constant;
|
2006-10-01 08:28:29 +02:00
|
|
|
txc->precision = 1;
|
2006-10-01 08:28:26 +02:00
|
|
|
txc->tolerance = MAXFREQ;
|
2006-10-01 08:28:22 +02:00
|
|
|
txc->tick = tick_usec;
|
|
|
|
|
|
|
|
/* PPS is not implemented, so these are zero */
|
|
|
|
txc->ppsfreq = 0;
|
|
|
|
txc->jitter = 0;
|
|
|
|
txc->shift = 0;
|
|
|
|
txc->stabil = 0;
|
|
|
|
txc->jitcnt = 0;
|
|
|
|
txc->calcnt = 0;
|
|
|
|
txc->errcnt = 0;
|
|
|
|
txc->stbcnt = 0;
|
|
|
|
write_sequnlock_irq(&xtime_lock);
|
|
|
|
do_gettimeofday(&txc->time);
|
|
|
|
notify_arch_cmos_timer();
|
|
|
|
return(result);
|
|
|
|
}
|