From 4117cd163977737a5e6633c7117d10aa194304cb Mon Sep 17 00:00:00 2001 From: Alexander Krutwig Date: Thu, 19 Mar 2015 11:38:14 +0100 Subject: timecounter: Import from FreeBSD Update #2271. --- cpukit/score/src/kern_tc.c | 2039 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 2039 insertions(+) create mode 100644 cpukit/score/src/kern_tc.c (limited to 'cpukit/score/src/kern_tc.c') diff --git a/cpukit/score/src/kern_tc.c b/cpukit/score/src/kern_tc.c new file mode 100644 index 0000000000..82e5e1e50c --- /dev/null +++ b/cpukit/score/src/kern_tc.c @@ -0,0 +1,2039 @@ +/*- + * ---------------------------------------------------------------------------- + * "THE BEER-WARE LICENSE" (Revision 42): + * wrote this file. As long as you retain this notice you + * can do whatever you want with this stuff. If we meet some day, and you think + * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp + * ---------------------------------------------------------------------------- + * + * Copyright (c) 2011 The FreeBSD Foundation + * All rights reserved. + * + * Portions of this software were developed by Julien Ridoux at the University + * of Melbourne under sponsorship from the FreeBSD Foundation. + */ + +#include +__FBSDID("$FreeBSD r277406 2015-01-20T03:54:30Z$"); + +#include "opt_compat.h" +#include "opt_ntp.h" +#include "opt_ffclock.h" + +#include +#include +#include +#ifdef FFCLOCK +#include +#include +#endif +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * A large step happens on boot. This constant detects such steps. + * It is relatively small so that ntp_update_second gets called enough + * in the typical 'missed a couple of seconds' case, but doesn't loop + * forever when the time step is large. + */ +#define LARGE_STEP 200 + +/* + * Implement a dummy timecounter which we can use until we get a real one + * in the air. This allows the console and other early stuff to use + * time services. + */ + +static u_int +dummy_get_timecount(struct timecounter *tc) +{ + static u_int now; + + return (++now); +} + +static struct timecounter dummy_timecounter = { + dummy_get_timecount, 0, ~0u, 1000000, "dummy", -1000000 +}; + +struct timehands { + /* These fields must be initialized by the driver. */ + struct timecounter *th_counter; + int64_t th_adjustment; + uint64_t th_scale; + u_int th_offset_count; + struct bintime th_offset; + struct timeval th_microtime; + struct timespec th_nanotime; + /* Fields not to be copied in tc_windup start with th_generation. */ + volatile u_int th_generation; + struct timehands *th_next; +}; + +static struct timehands th0; +static struct timehands th9 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th0}; +static struct timehands th8 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th9}; +static struct timehands th7 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th8}; +static struct timehands th6 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th7}; +static struct timehands th5 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th6}; +static struct timehands th4 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th5}; +static struct timehands th3 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th4}; +static struct timehands th2 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th3}; +static struct timehands th1 = { NULL, 0, 0, 0, {0, 0}, {0, 0}, {0, 0}, 0, &th2}; +static struct timehands th0 = { + &dummy_timecounter, + 0, + (uint64_t)-1 / 1000000, + 0, + {1, 0}, + {0, 0}, + {0, 0}, + 1, + &th1 +}; + +static struct timehands *volatile timehands = &th0; +struct timecounter *timecounter = &dummy_timecounter; +static struct timecounter *timecounters = &dummy_timecounter; + +int tc_min_ticktock_freq = 1; + +volatile time_t time_second = 1; +volatile time_t time_uptime = 1; + +struct bintime boottimebin; +struct timeval boottime; +static int sysctl_kern_boottime(SYSCTL_HANDLER_ARGS); +SYSCTL_PROC(_kern, KERN_BOOTTIME, boottime, CTLTYPE_STRUCT|CTLFLAG_RD, + NULL, 0, sysctl_kern_boottime, "S,timeval", "System boottime"); + +SYSCTL_NODE(_kern, OID_AUTO, timecounter, CTLFLAG_RW, 0, ""); +static SYSCTL_NODE(_kern_timecounter, OID_AUTO, tc, CTLFLAG_RW, 0, ""); + +static int timestepwarnings; +SYSCTL_INT(_kern_timecounter, OID_AUTO, stepwarnings, CTLFLAG_RW, + ×tepwarnings, 0, "Log time steps"); + +struct bintime bt_timethreshold; +struct bintime bt_tickthreshold; +sbintime_t sbt_timethreshold; +sbintime_t sbt_tickthreshold; +struct bintime tc_tick_bt; +sbintime_t tc_tick_sbt; +int tc_precexp; +int tc_timepercentage = TC_DEFAULTPERC; +static int sysctl_kern_timecounter_adjprecision(SYSCTL_HANDLER_ARGS); +SYSCTL_PROC(_kern_timecounter, OID_AUTO, alloweddeviation, + CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, 0, 0, + sysctl_kern_timecounter_adjprecision, "I", + "Allowed time interval deviation in percents"); + +static void tc_windup(void); +static void cpu_tick_calibrate(int); + +void dtrace_getnanotime(struct timespec *tsp); + +static int +sysctl_kern_boottime(SYSCTL_HANDLER_ARGS) +{ +#ifndef __mips__ +#ifdef SCTL_MASK32 + int tv[2]; + + if (req->flags & SCTL_MASK32) { + tv[0] = boottime.tv_sec; + tv[1] = boottime.tv_usec; + return SYSCTL_OUT(req, tv, sizeof(tv)); + } else +#endif +#endif + return SYSCTL_OUT(req, &boottime, sizeof(boottime)); +} + +static int +sysctl_kern_timecounter_get(SYSCTL_HANDLER_ARGS) +{ + u_int ncount; + struct timecounter *tc = arg1; + + ncount = tc->tc_get_timecount(tc); + return sysctl_handle_int(oidp, &ncount, 0, req); +} + +static int +sysctl_kern_timecounter_freq(SYSCTL_HANDLER_ARGS) +{ + uint64_t freq; + struct timecounter *tc = arg1; + + freq = tc->tc_frequency; + return sysctl_handle_64(oidp, &freq, 0, req); +} + +/* + * Return the difference between the timehands' counter value now and what + * was when we copied it to the timehands' offset_count. + */ +static __inline u_int +tc_delta(struct timehands *th) +{ + struct timecounter *tc; + + tc = th->th_counter; + return ((tc->tc_get_timecount(tc) - th->th_offset_count) & + tc->tc_counter_mask); +} + +/* + * Functions for reading the time. We have to loop until we are sure that + * the timehands that we operated on was not updated under our feet. See + * the comment in for a description of these 12 functions. + */ + +#ifdef FFCLOCK +void +fbclock_binuptime(struct bintime *bt) +{ + struct timehands *th; + unsigned int gen; + + do { + th = timehands; + gen = th->th_generation; + *bt = th->th_offset; + bintime_addx(bt, th->th_scale * tc_delta(th)); + } while (gen == 0 || gen != th->th_generation); +} + +void +fbclock_nanouptime(struct timespec *tsp) +{ + struct bintime bt; + + fbclock_binuptime(&bt); + bintime2timespec(&bt, tsp); +} + +void +fbclock_microuptime(struct timeval *tvp) +{ + struct bintime bt; + + fbclock_binuptime(&bt); + bintime2timeval(&bt, tvp); +} + +void +fbclock_bintime(struct bintime *bt) +{ + + fbclock_binuptime(bt); + bintime_add(bt, &boottimebin); +} + +void +fbclock_nanotime(struct timespec *tsp) +{ + struct bintime bt; + + fbclock_bintime(&bt); + bintime2timespec(&bt, tsp); +} + +void +fbclock_microtime(struct timeval *tvp) +{ + struct bintime bt; + + fbclock_bintime(&bt); + bintime2timeval(&bt, tvp); +} + +void +fbclock_getbinuptime(struct bintime *bt) +{ + struct timehands *th; + unsigned int gen; + + do { + th = timehands; + gen = th->th_generation; + *bt = th->th_offset; + } while (gen == 0 || gen != th->th_generation); +} + +void +fbclock_getnanouptime(struct timespec *tsp) +{ + struct timehands *th; + unsigned int gen; + + do { + th = timehands; + gen = th->th_generation; + bintime2timespec(&th->th_offset, tsp); + } while (gen == 0 || gen != th->th_generation); +} + +void +fbclock_getmicrouptime(struct timeval *tvp) +{ + struct timehands *th; + unsigned int gen; + + do { + th = timehands; + gen = th->th_generation; + bintime2timeval(&th->th_offset, tvp); + } while (gen == 0 || gen != th->th_generation); +} + +void +fbclock_getbintime(struct bintime *bt) +{ + struct timehands *th; + unsigned int gen; + + do { + th = timehands; + gen = th->th_generation; + *bt = th->th_offset; + } while (gen == 0 || gen != th->th_generation); + bintime_add(bt, &boottimebin); +} + +void +fbclock_getnanotime(struct timespec *tsp) +{ + struct timehands *th; + unsigned int gen; + + do { + th = timehands; + gen = th->th_generation; + *tsp = th->th_nanotime; + } while (gen == 0 || gen != th->th_generation); +} + +void +fbclock_getmicrotime(struct timeval *tvp) +{ + struct timehands *th; + unsigned int gen; + + do { + th = timehands; + gen = th->th_generation; + *tvp = th->th_microtime; + } while (gen == 0 || gen != th->th_generation); +} +#else /* !FFCLOCK */ +void +binuptime(struct bintime *bt) +{ + struct timehands *th; + u_int gen; + + do { + th = timehands; + gen = th->th_generation; + *bt = th->th_offset; + bintime_addx(bt, th->th_scale * tc_delta(th)); + } while (gen == 0 || gen != th->th_generation); +} + +void +nanouptime(struct timespec *tsp) +{ + struct bintime bt; + + binuptime(&bt); + bintime2timespec(&bt, tsp); +} + +void +microuptime(struct timeval *tvp) +{ + struct bintime bt; + + binuptime(&bt); + bintime2timeval(&bt, tvp); +} + +void +bintime(struct bintime *bt) +{ + + binuptime(bt); + bintime_add(bt, &boottimebin); +} + +void +nanotime(struct timespec *tsp) +{ + struct bintime bt; + + bintime(&bt); + bintime2timespec(&bt, tsp); +} + +void +microtime(struct timeval *tvp) +{ + struct bintime bt; + + bintime(&bt); + bintime2timeval(&bt, tvp); +} + +void +getbinuptime(struct bintime *bt) +{ + struct timehands *th; + u_int gen; + + do { + th = timehands; + gen = th->th_generation; + *bt = th->th_offset; + } while (gen == 0 || gen != th->th_generation); +} + +void +getnanouptime(struct timespec *tsp) +{ + struct timehands *th; + u_int gen; + + do { + th = timehands; + gen = th->th_generation; + bintime2timespec(&th->th_offset, tsp); + } while (gen == 0 || gen != th->th_generation); +} + +void +getmicrouptime(struct timeval *tvp) +{ + struct timehands *th; + u_int gen; + + do { + th = timehands; + gen = th->th_generation; + bintime2timeval(&th->th_offset, tvp); + } while (gen == 0 || gen != th->th_generation); +} + +void +getbintime(struct bintime *bt) +{ + struct timehands *th; + u_int gen; + + do { + th = timehands; + gen = th->th_generation; + *bt = th->th_offset; + } while (gen == 0 || gen != th->th_generation); + bintime_add(bt, &boottimebin); +} + +void +getnanotime(struct timespec *tsp) +{ + struct timehands *th; + u_int gen; + + do { + th = timehands; + gen = th->th_generation; + *tsp = th->th_nanotime; + } while (gen == 0 || gen != th->th_generation); +} + +void +getmicrotime(struct timeval *tvp) +{ + struct timehands *th; + u_int gen; + + do { + th = timehands; + gen = th->th_generation; + *tvp = th->th_microtime; + } while (gen == 0 || gen != th->th_generation); +} +#endif /* FFCLOCK */ + +#ifdef FFCLOCK +/* + * Support for feed-forward synchronization algorithms. This is heavily inspired + * by the timehands mechanism but kept independent from it. *_windup() functions + * have some connection to avoid accessing the timecounter hardware more than + * necessary. + */ + +/* Feed-forward clock estimates kept updated by the synchronization daemon. */ +struct ffclock_estimate ffclock_estimate; +struct bintime ffclock_boottime; /* Feed-forward boot time estimate. */ +uint32_t ffclock_status; /* Feed-forward clock status. */ +int8_t ffclock_updated; /* New estimates are available. */ +struct mtx ffclock_mtx; /* Mutex on ffclock_estimate. */ + +struct fftimehands { + struct ffclock_estimate cest; + struct bintime tick_time; + struct bintime tick_time_lerp; + ffcounter tick_ffcount; + uint64_t period_lerp; + volatile uint8_t gen; + struct fftimehands *next; +}; + +#define NUM_ELEMENTS(x) (sizeof(x) / sizeof(*x)) + +static struct fftimehands ffth[10]; +static struct fftimehands *volatile fftimehands = ffth; + +static void +ffclock_init(void) +{ + struct fftimehands *cur; + struct fftimehands *last; + + memset(ffth, 0, sizeof(ffth)); + + last = ffth + NUM_ELEMENTS(ffth) - 1; + for (cur = ffth; cur < last; cur++) + cur->next = cur + 1; + last->next = ffth; + + ffclock_updated = 0; + ffclock_status = FFCLOCK_STA_UNSYNC; + mtx_init(&ffclock_mtx, "ffclock lock", NULL, MTX_DEF); +} + +/* + * Reset the feed-forward clock estimates. Called from inittodr() to get things + * kick started and uses the timecounter nominal frequency as a first period + * estimate. Note: this function may be called several time just after boot. + * Note: this is the only function that sets the value of boot time for the + * monotonic (i.e. uptime) version of the feed-forward clock. + */ +void +ffclock_reset_clock(struct timespec *ts) +{ + struct timecounter *tc; + struct ffclock_estimate cest; + + tc = timehands->th_counter; + memset(&cest, 0, sizeof(struct ffclock_estimate)); + + timespec2bintime(ts, &ffclock_boottime); + timespec2bintime(ts, &(cest.update_time)); + ffclock_read_counter(&cest.update_ffcount); + cest.leapsec_next = 0; + cest.period = ((1ULL << 63) / tc->tc_frequency) << 1; + cest.errb_abs = 0; + cest.errb_rate = 0; + cest.status = FFCLOCK_STA_UNSYNC; + cest.leapsec_total = 0; + cest.leapsec = 0; + + mtx_lock(&ffclock_mtx); + bcopy(&cest, &ffclock_estimate, sizeof(struct ffclock_estimate)); + ffclock_updated = INT8_MAX; + mtx_unlock(&ffclock_mtx); + + printf("ffclock reset: %s (%llu Hz), time = %ld.%09lu\n", tc->tc_name, + (unsigned long long)tc->tc_frequency, (long)ts->tv_sec, + (unsigned long)ts->tv_nsec); +} + +/* + * Sub-routine to convert a time interval measured in RAW counter units to time + * in seconds stored in bintime format. + * NOTE: bintime_mul requires u_int, but the value of the ffcounter may be + * larger than the max value of u_int (on 32 bit architecture). Loop to consume + * extra cycles. + */ +static void +ffclock_convert_delta(ffcounter ffdelta, uint64_t period, struct bintime *bt) +{ + struct bintime bt2; + ffcounter delta, delta_max; + + delta_max = (1ULL << (8 * sizeof(unsigned int))) - 1; + bintime_clear(bt); + do { + if (ffdelta > delta_max) + delta = delta_max; + else + delta = ffdelta; + bt2.sec = 0; + bt2.frac = period; + bintime_mul(&bt2, (unsigned int)delta); + bintime_add(bt, &bt2); + ffdelta -= delta; + } while (ffdelta > 0); +} + +/* + * Update the fftimehands. + * Push the tick ffcount and time(s) forward based on current clock estimate. + * The conversion from ffcounter to bintime relies on the difference clock + * principle, whose accuracy relies on computing small time intervals. If a new + * clock estimate has been passed by the synchronisation daemon, make it + * current, and compute the linear interpolation for monotonic time if needed. + */ +static void +ffclock_windup(unsigned int delta) +{ + struct ffclock_estimate *cest; + struct fftimehands *ffth; + struct bintime bt, gap_lerp; + ffcounter ffdelta; + uint64_t frac; + unsigned int polling; + uint8_t forward_jump, ogen; + + /* + * Pick the next timehand, copy current ffclock estimates and move tick + * times and counter forward. + */ + forward_jump = 0; + ffth = fftimehands->next; + ogen = ffth->gen; + ffth->gen = 0; + cest = &ffth->cest; + bcopy(&fftimehands->cest, cest, sizeof(struct ffclock_estimate)); + ffdelta = (ffcounter)delta; + ffth->period_lerp = fftimehands->period_lerp; + + ffth->tick_time = fftimehands->tick_time; + ffclock_convert_delta(ffdelta, cest->period, &bt); + bintime_add(&ffth->tick_time, &bt); + + ffth->tick_time_lerp = fftimehands->tick_time_lerp; + ffclock_convert_delta(ffdelta, ffth->period_lerp, &bt); + bintime_add(&ffth->tick_time_lerp, &bt); + + ffth->tick_ffcount = fftimehands->tick_ffcount + ffdelta; + + /* + * Assess the status of the clock, if the last update is too old, it is + * likely the synchronisation daemon is dead and the clock is free + * running. + */ + if (ffclock_updated == 0) { + ffdelta = ffth->tick_ffcount - cest->update_ffcount; + ffclock_convert_delta(ffdelta, cest->period, &bt); + if (bt.sec > 2 * FFCLOCK_SKM_SCALE) + ffclock_status |= FFCLOCK_STA_UNSYNC; + } + + /* + * If available, grab updated clock estimates and make them current. + * Recompute time at this tick using the updated estimates. The clock + * estimates passed the feed-forward synchronisation daemon may result + * in time conversion that is not monotonically increasing (just after + * the update). time_lerp is a particular linear interpolation over the + * synchronisation algo polling period that ensures monotonicity for the + * clock ids requesting it. + */ + if (ffclock_updated > 0) { + bcopy(&ffclock_estimate, cest, sizeof(struct ffclock_estimate)); + ffdelta = ffth->tick_ffcount - cest->update_ffcount; + ffth->tick_time = cest->update_time; + ffclock_convert_delta(ffdelta, cest->period, &bt); + bintime_add(&ffth->tick_time, &bt); + + /* ffclock_reset sets ffclock_updated to INT8_MAX */ + if (ffclock_updated == INT8_MAX) + ffth->tick_time_lerp = ffth->tick_time; + + if (bintime_cmp(&ffth->tick_time, &ffth->tick_time_lerp, >)) + forward_jump = 1; + else + forward_jump = 0; + + bintime_clear(&gap_lerp); + if (forward_jump) { + gap_lerp = ffth->tick_time; + bintime_sub(&gap_lerp, &ffth->tick_time_lerp); + } else { + gap_lerp = ffth->tick_time_lerp; + bintime_sub(&gap_lerp, &ffth->tick_time); + } + + /* + * The reset from the RTC clock may be far from accurate, and + * reducing the gap between real time and interpolated time + * could take a very long time if the interpolated clock insists + * on strict monotonicity. The clock is reset under very strict + * conditions (kernel time is known to be wrong and + * synchronization daemon has been restarted recently. + * ffclock_boottime absorbs the jump to ensure boot time is + * correct and uptime functions stay consistent. + */ + if (((ffclock_status & FFCLOCK_STA_UNSYNC) == FFCLOCK_STA_UNSYNC) && + ((cest->status & FFCLOCK_STA_UNSYNC) == 0) && + ((cest->status & FFCLOCK_STA_WARMUP) == FFCLOCK_STA_WARMUP)) { + if (forward_jump) + bintime_add(&ffclock_boottime, &gap_lerp); + else + bintime_sub(&ffclock_boottime, &gap_lerp); + ffth->tick_time_lerp = ffth->tick_time; + bintime_clear(&gap_lerp); + } + + ffclock_status = cest->status; + ffth->period_lerp = cest->period; + + /* + * Compute corrected period used for the linear interpolation of + * time. The rate of linear interpolation is capped to 5000PPM + * (5ms/s). + */ + if (bintime_isset(&gap_lerp)) { + ffdelta = cest->update_ffcount; + ffdelta -= fftimehands->cest.update_ffcount; + ffclock_convert_delta(ffdelta, cest->period, &bt); + polling = bt.sec; + bt.sec = 0; + bt.frac = 5000000 * (uint64_t)18446744073LL; + bintime_mul(&bt, polling); + if (bintime_cmp(&gap_lerp, &bt, >)) + gap_lerp = bt; + + /* Approximate 1 sec by 1-(1/2^64) to ease arithmetic */ + frac = 0; + if (gap_lerp.sec > 0) { + frac -= 1; + frac /= ffdelta / gap_lerp.sec; + } + frac += gap_lerp.frac / ffdelta; + + if (forward_jump) + ffth->period_lerp += frac; + else + ffth->period_lerp -= frac; + } + + ffclock_updated = 0; + } + if (++ogen == 0) + ogen = 1; + ffth->gen = ogen; + fftimehands = ffth; +} + +/* + * Adjust the fftimehands when the timecounter is changed. Stating the obvious, + * the old and new hardware counter cannot be read simultaneously. tc_windup() + * does read the two counters 'back to back', but a few cycles are effectively + * lost, and not accumulated in tick_ffcount. This is a fairly radical + * operation for a feed-forward synchronization daemon, and it is its job to not + * pushing irrelevant data to the kernel. Because there is no locking here, + * simply force to ignore pending or next update to give daemon a chance to + * realize the counter has changed. + */ +static void +ffclock_change_tc(struct timehands *th) +{ + struct fftimehands *ffth; + struct ffclock_estimate *cest; + struct timecounter *tc; + uint8_t ogen; + + tc = th->th_counter; + ffth = fftimehands->next; + ogen = ffth->gen; + ffth->gen = 0; + + cest = &ffth->cest; + bcopy(&(fftimehands->cest), cest, sizeof(struct ffclock_estimate)); + cest->period = ((1ULL << 63) / tc->tc_frequency ) << 1; + cest->errb_abs = 0; + cest->errb_rate = 0; + cest->status |= FFCLOCK_STA_UNSYNC; + + ffth->tick_ffcount = fftimehands->tick_ffcount; + ffth->tick_time_lerp = fftimehands->tick_time_lerp; + ffth->tick_time = fftimehands->tick_time; + ffth->period_lerp = cest->period; + + /* Do not lock but ignore next update from synchronization daemon. */ + ffclock_updated--; + + if (++ogen == 0) + ogen = 1; + ffth->gen = ogen; + fftimehands = ffth; +} + +/* + * Retrieve feed-forward counter and time of last kernel tick. + */ +void +ffclock_last_tick(ffcounter *ffcount, struct bintime *bt, uint32_t flags) +{ + struct fftimehands *ffth; + uint8_t gen; + + /* + * No locking but check generation has not changed. Also need to make + * sure ffdelta is positive, i.e. ffcount > tick_ffcount. + */ + do { + ffth = fftimehands; + gen = ffth->gen; + if ((flags & FFCLOCK_LERP) == FFCLOCK_LERP) + *bt = ffth->tick_time_lerp; + else + *bt = ffth->tick_time; + *ffcount = ffth->tick_ffcount; + } while (gen == 0 || gen != ffth->gen); +} + +/* + * Absolute clock conversion. Low level function to convert ffcounter to + * bintime. The ffcounter is converted using the current ffclock period estimate + * or the "interpolated period" to ensure monotonicity. + * NOTE: this conversion may have been deferred, and the clock updated since the + * hardware counter has been read. + */ +void +ffclock_convert_abs(ffcounter ffcount, struct bintime *bt, uint32_t flags) +{ + struct fftimehands *ffth; + struct bintime bt2; + ffcounter ffdelta; + uint8_t gen; + + /* + * No locking but check generation has not changed. Also need to make + * sure ffdelta is positive, i.e. ffcount > tick_ffcount. + */ + do { + ffth = fftimehands; + gen = ffth->gen; + if (ffcount > ffth->tick_ffcount) + ffdelta = ffcount - ffth->tick_ffcount; + else + ffdelta = ffth->tick_ffcount - ffcount; + + if ((flags & FFCLOCK_LERP) == FFCLOCK_LERP) { + *bt = ffth->tick_time_lerp; + ffclock_convert_delta(ffdelta, ffth->period_lerp, &bt2); + } else { + *bt = ffth->tick_time; + ffclock_convert_delta(ffdelta, ffth->cest.period, &bt2); + } + + if (ffcount > ffth->tick_ffcount) + bintime_add(bt, &bt2); + else + bintime_sub(bt, &bt2); + } while (gen == 0 || gen != ffth->gen); +} + +/* + * Difference clock conversion. + * Low level function to Convert a time interval measured in RAW counter units + * into bintime. The difference clock allows measuring small intervals much more + * reliably than the absolute clock. + */ +void +ffclock_convert_diff(ffcounter ffdelta, struct bintime *bt) +{ + struct fftimehands *ffth; + uint8_t gen; + + /* No locking but check generation has not changed. */ + do { + ffth = fftimehands; + gen = ffth->gen; + ffclock_convert_delta(ffdelta, ffth->cest.period, bt); + } while (gen == 0 || gen != ffth->gen); +} + +/* + * Access to current ffcounter value. + */ +void +ffclock_read_counter(ffcounter *ffcount) +{ + struct timehands *th; + struct fftimehands *ffth; + unsigned int gen, delta; + + /* + * ffclock_windup() called from tc_windup(), safe to rely on + * th->th_generation only, for correct delta and ffcounter. + */ + do { + th = timehands; + gen = th->th_generation; + ffth = fftimehands; + delta = tc_delta(th); + *ffcount = ffth->tick_ffcount; + } while (gen == 0 || gen != th->th_generation); + + *ffcount += delta; +} + +void +binuptime(struct bintime *bt) +{ + + binuptime_fromclock(bt, sysclock_active); +} + +void +nanouptime(struct timespec *tsp) +{ + + nanouptime_fromclock(tsp, sysclock_active); +} + +void +microuptime(struct timeval *tvp) +{ + + microuptime_fromclock(tvp, sysclock_active); +} + +void +bintime(struct bintime *bt) +{ + + bintime_fromclock(bt, sysclock_active); +} + +void +nanotime(struct timespec *tsp) +{ + + nanotime_fromclock(tsp, sysclock_active); +} + +void +microtime(struct timeval *tvp) +{ + + microtime_fromclock(tvp, sysclock_active); +} + +void +getbinuptime(struct bintime *bt) +{ + + getbinuptime_fromclock(bt, sysclock_active); +} + +void +getnanouptime(struct timespec *tsp) +{ + + getnanouptime_fromclock(tsp, sysclock_active); +} + +void +getmicrouptime(struct timeval *tvp) +{ + + getmicrouptime_fromclock(tvp, sysclock_active); +} + +void +getbintime(struct bintime *bt) +{ + + getbintime_fromclock(bt, sysclock_active); +} + +void +getnanotime(struct timespec *tsp) +{ + + getnanotime_fromclock(tsp, sysclock_active); +} + +void +getmicrotime(struct timeval *tvp) +{ + + getmicrouptime_fromclock(tvp, sysclock_active); +} + +#endif /* FFCLOCK */ + +/* + * This is a clone of getnanotime and used for walltimestamps. + * The dtrace_ prefix prevents fbt from creating probes for + * it so walltimestamp can be safely used in all fbt probes. + */ +void +dtrace_getnanotime(struct timespec *tsp) +{ + struct timehands *th; + u_int gen; + + do { + th = timehands; + gen = th->th_generation; + *tsp = th->th_nanotime; + } while (gen == 0 || gen != th->th_generation); +} + +/* + * System clock currently providing time to the system. Modifiable via sysctl + * when the FFCLOCK option is defined. + */ +int sysclock_active = SYSCLOCK_FBCK; + +/* Internal NTP status and error estimates. */ +extern int time_status; +extern long time_esterror; + +/* + * Take a snapshot of sysclock data which can be used to compare system clocks + * and generate timestamps after the fact. + */ +void +sysclock_getsnapshot(struct sysclock_snap *clock_snap, int fast) +{ + struct fbclock_info *fbi; + struct timehands *th; + struct bintime bt; + unsigned int delta, gen; +#ifdef FFCLOCK + ffcounter ffcount; + struct fftimehands *ffth; + struct ffclock_info *ffi; + struct ffclock_estimate cest; + + ffi = &clock_snap->ff_info; +#endif + + fbi = &clock_snap->fb_info; + delta = 0; + + do { + th = timehands; + gen = th->th_generation; + fbi->th_scale = th->th_scale; + fbi->tick_time = th->th_offset; +#ifdef FFCLOCK + ffth = fftimehands; + ffi->tick_time = ffth->tick_time_lerp; + ffi->tick_time_lerp = ffth->tick_time_lerp; + ffi->period = ffth->cest.period; + ffi->period_lerp = ffth->period_lerp; + clock_snap->ffcount = ffth->tick_ffcount; + cest = ffth->cest; +#endif + if (!fast) + delta = tc_delta(th); + } while (gen == 0 || gen != th->th_generation); + + clock_snap->delta = delta; + clock_snap->sysclock_active = sysclock_active; + + /* Record feedback clock status and error. */ + clock_snap->fb_info.status = time_status; + /* XXX: Very crude estimate of feedback clock error. */ + bt.sec = time_esterror / 1000000; + bt.frac = ((time_esterror - bt.sec) * 1000000) * + (uint64_t)18446744073709ULL; + clock_snap->fb_info.error = bt; + +#ifdef FFCLOCK + if (!fast) + clock_snap->ffcount += delta; + + /* Record feed-forward clock leap second adjustment. */ + ffi->leapsec_adjustment = cest.leapsec_total; + if (clock_snap->ffcount > cest.leapsec_next) + ffi->leapsec_adjustment -= cest.leapsec; + + /* Record feed-forward clock status and error. */ + clock_snap->ff_info.status = cest.status; + ffcount = clock_snap->ffcount - cest.update_ffcount; + ffclock_convert_delta(ffcount, cest.period, &bt); + /* 18446744073709 = int(2^64/1e12), err_bound_rate in [ps/s]. */ + bintime_mul(&bt, cest.errb_rate * (uint64_t)18446744073709ULL); + /* 18446744073 = int(2^64 / 1e9), since err_abs in [ns]. */ + bintime_addx(&bt, cest.errb_abs * (uint64_t)18446744073ULL); + clock_snap->ff_info.error = bt; +#endif +} + +/* + * Convert a sysclock snapshot into a struct bintime based on the specified + * clock source and flags. + */ +int +sysclock_snap2bintime(struct sysclock_snap *cs, struct bintime *bt, + int whichclock, uint32_t flags) +{ +#ifdef FFCLOCK + struct bintime bt2; + uint64_t period; +#endif + + switch (whichclock) { + case SYSCLOCK_FBCK: + *bt = cs->fb_info.tick_time; + + /* If snapshot was created with !fast, delta will be >0. */ + if (cs->delta > 0) + bintime_addx(bt, cs->fb_info.th_scale * cs->delta); + + if ((flags & FBCLOCK_UPTIME) == 0) + bintime_add(bt, &boottimebin); + break; +#ifdef FFCLOCK + case SYSCLOCK_FFWD: + if (flags & FFCLOCK_LERP) { + *bt = cs->ff_info.tick_time_lerp; + period = cs->ff_info.period_lerp; + } else { + *bt = cs->ff_info.tick_time; + period = cs->ff_info.period; + } + + /* If snapshot was created with !fast, delta will be >0. */ + if (cs->delta > 0) { + ffclock_convert_delta(cs->delta, period, &bt2); + bintime_add(bt, &bt2); + } + + /* Leap second adjustment. */ + if (flags & FFCLOCK_LEAPSEC) + bt->sec -= cs->ff_info.leapsec_adjustment; + + /* Boot time adjustment, for uptime/monotonic clocks. */ + if (flags & FFCLOCK_UPTIME) + bintime_sub(bt, &ffclock_boottime); + break; +#endif + default: + return (EINVAL); + break; + } + + return (0); +} + +/* + * Initialize a new timecounter and possibly use it. + */ +void +tc_init(struct timecounter *tc) +{ + u_int u; + struct sysctl_oid *tc_root; + + u = tc->tc_frequency / tc->tc_counter_mask; + /* XXX: We need some margin here, 10% is a guess */ + u *= 11; + u /= 10; + if (u > hz && tc->tc_quality >= 0) { + tc->tc_quality = -2000; + if (bootverbose) { + printf("Timecounter \"%s\" frequency %ju Hz", + tc->tc_name, (uintmax_t)tc->tc_frequency); + printf(" -- Insufficient hz, needs at least %u\n", u); + } + } else if (tc->tc_quality >= 0 || bootverbose) { + printf("Timecounter \"%s\" frequency %ju Hz quality %d\n", + tc->tc_name, (uintmax_t)tc->tc_frequency, + tc->tc_quality); + } + + tc->tc_next = timecounters; + timecounters = tc; + /* + * Set up sysctl tree for this counter. + */ + tc_root = SYSCTL_ADD_NODE(NULL, + SYSCTL_STATIC_CHILDREN(_kern_timecounter_tc), OID_AUTO, tc->tc_name, + CTLFLAG_RW, 0, "timecounter description"); + SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, + "mask", CTLFLAG_RD, &(tc->tc_counter_mask), 0, + "mask for implemented bits"); + SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, + "counter", CTLTYPE_UINT | CTLFLAG_RD, tc, sizeof(*tc), + sysctl_kern_timecounter_get, "IU", "current timecounter value"); + SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, + "frequency", CTLTYPE_U64 | CTLFLAG_RD, tc, sizeof(*tc), + sysctl_kern_timecounter_freq, "QU", "timecounter frequency"); + SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(tc_root), OID_AUTO, + "quality", CTLFLAG_RD, &(tc->tc_quality), 0, + "goodness of time counter"); + /* + * Never automatically use a timecounter with negative quality. + * Even though we run on the dummy counter, switching here may be + * worse since this timecounter may not be monotonous. + */ + if (tc->tc_quality < 0) + return; + if (tc->tc_quality < timecounter->tc_quality) + return; + if (tc->tc_quality == timecounter->tc_quality && + tc->tc_frequency < timecounter->tc_frequency) + return; + (void)tc->tc_get_timecount(tc); + (void)tc->tc_get_timecount(tc); + timecounter = tc; +} + +/* Report the frequency of the current timecounter. */ +uint64_t +tc_getfrequency(void) +{ + + return (timehands->th_counter->tc_frequency); +} + +/* + * Step our concept of UTC. This is done by modifying our estimate of + * when we booted. + * XXX: not locked. + */ +void +tc_setclock(struct timespec *ts) +{ + struct timespec tbef, taft; + struct bintime bt, bt2; + + cpu_tick_calibrate(1); + nanotime(&tbef); + timespec2bintime(ts, &bt); + binuptime(&bt2); + bintime_sub(&bt, &bt2); + bintime_add(&bt2, &boottimebin); + boottimebin = bt; + bintime2timeval(&bt, &boottime); + + /* XXX fiddle all the little crinkly bits around the fiords... */ + tc_windup(); + nanotime(&taft); + if (timestepwarnings) { + log(LOG_INFO, + "Time stepped from %jd.%09ld to %jd.%09ld (%jd.%09ld)\n", + (intmax_t)tbef.tv_sec, tbef.tv_nsec, + (intmax_t)taft.tv_sec, taft.tv_nsec, + (intmax_t)ts->tv_sec, ts->tv_nsec); + } + cpu_tick_calibrate(1); +} + +/* + * Initialize the next struct timehands in the ring and make + * it the active timehands. Along the way we might switch to a different + * timecounter and/or do seconds processing in NTP. Slightly magic. + */ +static void +tc_windup(void) +{ + struct bintime bt; + struct timehands *th, *tho; + uint64_t scale; + u_int delta, ncount, ogen; + int i; + time_t t; + + /* + * Make the next timehands a copy of the current one, but do not + * overwrite the generation or next pointer. While we update + * the contents, the generation must be zero. + */ + tho = timehands; + th = tho->th_next; + ogen = th->th_generation; + th->th_generation = 0; + bcopy(tho, th, offsetof(struct timehands, th_generation)); + + /* + * Capture a timecounter delta on the current timecounter and if + * changing timecounters, a counter value from the new timecounter. + * Update the offset fields accordingly. + */ + delta = tc_delta(th); + if (th->th_counter != timecounter) + ncount = timecounter->tc_get_timecount(timecounter); + else + ncount = 0; +#ifdef FFCLOCK + ffclock_windup(delta); +#endif + th->th_offset_count += delta; + th->th_offset_count &= th->th_counter->tc_counter_mask; + while (delta > th->th_counter->tc_frequency) { + /* Eat complete unadjusted seconds. */ + delta -= th->th_counter->tc_frequency; + th->th_offset.sec++; + } + if ((delta > th->th_counter->tc_frequency / 2) && + (th->th_scale * delta < ((uint64_t)1 << 63))) { + /* The product th_scale * delta just barely overflows. */ + th->th_offset.sec++; + } + bintime_addx(&th->th_offset, th->th_scale * delta); + + /* + * Hardware latching timecounters may not generate interrupts on + * PPS events, so instead we poll them. There is a finite risk that + * the hardware might capture a count which is later than the one we + * got above, and therefore possibly in the next NTP second which might + * have a different rate than the current NTP second. It doesn't + * matter in practice. + */ + if (tho->th_counter->tc_poll_pps) + tho->th_counter->tc_poll_pps(tho->th_counter); + + /* + * Deal with NTP second processing. The for loop normally + * iterates at most once, but in extreme situations it might + * keep NTP sane if timeouts are not run for several seconds. + * At boot, the time step can be large when the TOD hardware + * has been read, so on really large steps, we call + * ntp_update_second only twice. We need to call it twice in + * case we missed a leap second. + */ + bt = th->th_offset; + bintime_add(&bt, &boottimebin); + i = bt.sec - tho->th_microtime.tv_sec; + if (i > LARGE_STEP) + i = 2; + for (; i > 0; i--) { + t = bt.sec; + ntp_update_second(&th->th_adjustment, &bt.sec); + if (bt.sec != t) + boottimebin.sec += bt.sec - t; + } + /* Update the UTC timestamps used by the get*() functions. */ + /* XXX shouldn't do this here. Should force non-`get' versions. */ + bintime2timeval(&bt, &th->th_microtime); + bintime2timespec(&bt, &th->th_nanotime); + + /* Now is a good time to change timecounters. */ + if (th->th_counter != timecounter) { +#ifndef __arm__ + if ((timecounter->tc_flags & TC_FLAGS_C2STOP) != 0) + cpu_disable_c2_sleep++; + if ((th->th_counter->tc_flags & TC_FLAGS_C2STOP) != 0) + cpu_disable_c2_sleep--; +#endif + th->th_counter = timecounter; + th->th_offset_count = ncount; + tc_min_ticktock_freq = max(1, timecounter->tc_frequency / + (((uint64_t)timecounter->tc_counter_mask + 1) / 3)); +#ifdef FFCLOCK + ffclock_change_tc(th); +#endif + } + + /*- + * Recalculate the scaling factor. We want the number of 1/2^64 + * fractions of a second per period of the hardware counter, taking + * into account the th_adjustment factor which the NTP PLL/adjtime(2) + * processing provides us with. + * + * The th_adjustment is nanoseconds per second with 32 bit binary + * fraction and we want 64 bit binary fraction of second: + * + * x = a * 2^32 / 10^9 = a * 4.294967296 + * + * The range of th_adjustment is +/- 5000PPM so inside a 64bit int + * we can only multiply by about 850 without overflowing, that + * leaves no suitably precise fractions for multiply before divide. + * + * Divide before multiply with a fraction of 2199/512 results in a + * systematic undercompensation of 10PPM of th_adjustment. On a + * 5000PPM adjustment this is a 0.05PPM error. This is acceptable. + * + * We happily sacrifice the lowest of the 64 bits of our result + * to the goddess of code clarity. + * + */ + scale = (uint64_t)1 << 63; + scale += (th->th_adjustment / 1024) * 2199; + scale /= th->th_counter->tc_frequency; + th->th_scale = scale * 2; + + /* + * Now that the struct timehands is again consistent, set the new + * generation number, making sure to not make it zero. + */ + if (++ogen == 0) + ogen = 1; + th->th_generation = ogen; + + /* Go live with the new struct timehands. */ +#ifdef FFCLOCK + switch (sysclock_active) { + case SYSCLOCK_FBCK: +#endif + time_second = th->th_microtime.tv_sec; + time_uptime = th->th_offset.sec; +#ifdef FFCLOCK + break; + case SYSCLOCK_FFWD: + time_second = fftimehands->tick_time_lerp.sec; + time_uptime = fftimehands->tick_time_lerp.sec - ffclock_boottime.sec; + break; + } +#endif + + timehands = th; + timekeep_push_vdso(); +} + +/* Report or change the active timecounter hardware. */ +static int +sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS) +{ + char newname[32]; + struct timecounter *newtc, *tc; + int error; + + tc = timecounter; + strlcpy(newname, tc->tc_name, sizeof(newname)); + + error = sysctl_handle_string(oidp, &newname[0], sizeof(newname), req); + if (error != 0 || req->newptr == NULL || + strcmp(newname, tc->tc_name) == 0) + return (error); + for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { + if (strcmp(newname, newtc->tc_name) != 0) + continue; + + /* Warm up new timecounter. */ + (void)newtc->tc_get_timecount(newtc); + (void)newtc->tc_get_timecount(newtc); + + timecounter = newtc; + + /* + * The vdso timehands update is deferred until the next + * 'tc_windup()'. + * + * This is prudent given that 'timekeep_push_vdso()' does not + * use any locking and that it can be called in hard interrupt + * context via 'tc_windup()'. + */ + return (0); + } + return (EINVAL); +} + +SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW, + 0, 0, sysctl_kern_timecounter_hardware, "A", + "Timecounter hardware selected"); + + +/* Report or change the active timecounter hardware. */ +static int +sysctl_kern_timecounter_choice(SYSCTL_HANDLER_ARGS) +{ + char buf[32], *spc; + struct timecounter *tc; + int error; + + spc = ""; + error = 0; + for (tc = timecounters; error == 0 && tc != NULL; tc = tc->tc_next) { + sprintf(buf, "%s%s(%d)", + spc, tc->tc_name, tc->tc_quality); + error = SYSCTL_OUT(req, buf, strlen(buf)); + spc = " "; + } + return (error); +} + +SYSCTL_PROC(_kern_timecounter, OID_AUTO, choice, CTLTYPE_STRING | CTLFLAG_RD, + 0, 0, sysctl_kern_timecounter_choice, "A", "Timecounter hardware detected"); + +/* + * RFC 2783 PPS-API implementation. + */ + +static int +pps_fetch(struct pps_fetch_args *fapi, struct pps_state *pps) +{ + int err, timo; + pps_seq_t aseq, cseq; + struct timeval tv; + + if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC) + return (EINVAL); + + /* + * If no timeout is requested, immediately return whatever values were + * most recently captured. If timeout seconds is -1, that's a request + * to block without a timeout. WITNESS won't let us sleep forever + * without a lock (we really don't need a lock), so just repeatedly + * sleep a long time. + */ + if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec) { + if (fapi->timeout.tv_sec == -1) + timo = 0x7fffffff; + else { + tv.tv_sec = fapi->timeout.tv_sec; + tv.tv_usec = fapi->timeout.tv_nsec / 1000; + timo = tvtohz(&tv); + } + aseq = pps->ppsinfo.assert_sequence; + cseq = pps->ppsinfo.clear_sequence; + while (aseq == pps->ppsinfo.assert_sequence && + cseq == pps->ppsinfo.clear_sequence) { + err = tsleep(pps, PCATCH, "ppsfch", timo); + if (err == EWOULDBLOCK && fapi->timeout.tv_sec == -1) { + continue; + } else if (err != 0) { + return (err); + } + } + } + + pps->ppsinfo.current_mode = pps->ppsparam.mode; + fapi->pps_info_buf = pps->ppsinfo; + + return (0); +} + +int +pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps) +{ + pps_params_t *app; + struct pps_fetch_args *fapi; +#ifdef FFCLOCK + struct pps_fetch_ffc_args *fapi_ffc; +#endif +#ifdef PPS_SYNC + struct pps_kcbind_args *kapi; +#endif + + KASSERT(pps != NULL, ("NULL pps pointer in pps_ioctl")); + switch (cmd) { + case PPS_IOC_CREATE: + return (0); + case PPS_IOC_DESTROY: + return (0); + case PPS_IOC_SETPARAMS: + app = (pps_params_t *)data; + if (app->mode & ~pps->ppscap) + return (EINVAL); +#ifdef FFCLOCK + /* Ensure only a single clock is selected for ffc timestamp. */ + if ((app->mode & PPS_TSCLK_MASK) == PPS_TSCLK_MASK) + return (EINVAL); +#endif + pps->ppsparam = *app; + return (0); + case PPS_IOC_GETPARAMS: + app = (pps_params_t *)data; + *app = pps->ppsparam; + app->api_version = PPS_API_VERS_1; + return (0); + case PPS_IOC_GETCAP: + *(int*)data = pps->ppscap; + return (0); + case PPS_IOC_FETCH: + fapi = (struct pps_fetch_args *)data; + return (pps_fetch(fapi, pps)); +#ifdef FFCLOCK + case PPS_IOC_FETCH_FFCOUNTER: + fapi_ffc = (struct pps_fetch_ffc_args *)data; + if (fapi_ffc->tsformat && fapi_ffc->tsformat != + PPS_TSFMT_TSPEC) + return (EINVAL); + if (fapi_ffc->timeout.tv_sec || fapi_ffc->timeout.tv_nsec) + return (EOPNOTSUPP); + pps->ppsinfo_ffc.current_mode = pps->ppsparam.mode; + fapi_ffc->pps_info_buf_ffc = pps->ppsinfo_ffc; + /* Overwrite timestamps if feedback clock selected. */ + switch (pps->ppsparam.mode & PPS_TSCLK_MASK) { + case PPS_TSCLK_FBCK: + fapi_ffc->pps_info_buf_ffc.assert_timestamp = + pps->ppsinfo.assert_timestamp; + fapi_ffc->pps_info_buf_ffc.clear_timestamp = + pps->ppsinfo.clear_timestamp; + break; + case PPS_TSCLK_FFWD: + break; + default: + break; + } + return (0); +#endif /* FFCLOCK */ + case PPS_IOC_KCBIND: +#ifdef PPS_SYNC + kapi = (struct pps_kcbind_args *)data; + /* XXX Only root should be able to do this */ + if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC) + return (EINVAL); + if (kapi->kernel_consumer != PPS_KC_HARDPPS) + return (EINVAL); + if (kapi->edge & ~pps->ppscap) + return (EINVAL); + pps->kcmode = kapi->edge; + return (0); +#else + return (EOPNOTSUPP); +#endif + default: + return (ENOIOCTL); + } +} + +void +pps_init(struct pps_state *pps) +{ + pps->ppscap |= PPS_TSFMT_TSPEC | PPS_CANWAIT; + if (pps->ppscap & PPS_CAPTUREASSERT) + pps->ppscap |= PPS_OFFSETASSERT; + if (pps->ppscap & PPS_CAPTURECLEAR) + pps->ppscap |= PPS_OFFSETCLEAR; +#ifdef FFCLOCK + pps->ppscap |= PPS_TSCLK_MASK; +#endif +} + +void +pps_capture(struct pps_state *pps) +{ + struct timehands *th; + + KASSERT(pps != NULL, ("NULL pps pointer in pps_capture")); + th = timehands; + pps->capgen = th->th_generation; + pps->capth = th; +#ifdef FFCLOCK + pps->capffth = fftimehands; +#endif + pps->capcount = th->th_counter->tc_get_timecount(th->th_counter); + if (pps->capgen != th->th_generation) + pps->capgen = 0; +} + +void +pps_event(struct pps_state *pps, int event) +{ + struct bintime bt; + struct timespec ts, *tsp, *osp; + u_int tcount, *pcount; + int foff, fhard; + pps_seq_t *pseq; +#ifdef FFCLOCK + struct timespec *tsp_ffc; + pps_seq_t *pseq_ffc; + ffcounter *ffcount; +#endif + + KASSERT(pps != NULL, ("NULL pps pointer in pps_event")); + /* If the timecounter was wound up underneath us, bail out. */ + if (pps->capgen == 0 || pps->capgen != pps->capth->th_generation) + return; + + /* Things would be easier with arrays. */ + if (event == PPS_CAPTUREASSERT) { + tsp = &pps->ppsinfo.assert_timestamp; + osp = &pps->ppsparam.assert_offset; + foff = pps->ppsparam.mode & PPS_OFFSETASSERT; + fhard = pps->kcmode & PPS_CAPTUREASSERT; + pcount = &pps->ppscount[0]; + pseq = &pps->ppsinfo.assert_sequence; +#ifdef FFCLOCK + ffcount = &pps->ppsinfo_ffc.assert_ffcount; + tsp_ffc = &pps->ppsinfo_ffc.assert_timestamp; + pseq_ffc = &pps->ppsinfo_ffc.assert_sequence; +#endif + } else { + tsp = &pps->ppsinfo.clear_timestamp; + osp = &pps->ppsparam.clear_offset; + foff = pps->ppsparam.mode & PPS_OFFSETCLEAR; + fhard = pps->kcmode & PPS_CAPTURECLEAR; + pcount = &pps->ppscount[1]; + pseq = &pps->ppsinfo.clear_sequence; +#ifdef FFCLOCK + ffcount = &pps->ppsinfo_ffc.clear_ffcount; + tsp_ffc = &pps->ppsinfo_ffc.clear_timestamp; + pseq_ffc = &pps->ppsinfo_ffc.clear_sequence; +#endif + } + + /* + * If the timecounter changed, we cannot compare the count values, so + * we have to drop the rest of the PPS-stuff until the next event. + */ + if (pps->ppstc != pps->capth->th_counter) { + pps->ppstc = pps->capth->th_counter; + *pcount = pps->capcount; + pps->ppscount[2] = pps->capcount; + return; + } + + /* Convert the count to a timespec. */ + tcount = pps->capcount - pps->capth->th_offset_count; + tcount &= pps->capth->th_counter->tc_counter_mask; + bt = pps->capth->th_offset; + bintime_addx(&bt, pps->capth->th_scale * tcount); + bintime_add(&bt, &boottimebin); + bintime2timespec(&bt, &ts); + + /* If the timecounter was wound up underneath us, bail out. */ + if (pps->capgen != pps->capth->th_generation) + return; + + *pcount = pps->capcount; + (*pseq)++; + *tsp = ts; + + if (foff) { + timespecadd(tsp, osp); + if (tsp->tv_nsec < 0) { + tsp->tv_nsec += 1000000000; + tsp->tv_sec -= 1; + } + } + +#ifdef FFCLOCK + *ffcount = pps->capffth->tick_ffcount + tcount; + bt = pps->capffth->tick_time; + ffclock_convert_delta(tcount, pps->capffth->cest.period, &bt); + bintime_add(&bt, &pps->capffth->tick_time); + bintime2timespec(&bt, &ts); + (*pseq_ffc)++; + *tsp_ffc = ts; +#endif + +#ifdef PPS_SYNC + if (fhard) { + uint64_t scale; + + /* + * Feed the NTP PLL/FLL. + * The FLL wants to know how many (hardware) nanoseconds + * elapsed since the previous event. + */ + tcount = pps->capcount - pps->ppscount[2]; + pps->ppscount[2] = pps->capcount; + tcount &= pps->capth->th_counter->tc_counter_mask; + scale = (uint64_t)1 << 63; + scale /= pps->capth->th_counter->tc_frequency; + scale *= 2; + bt.sec = 0; + bt.frac = 0; + bintime_addx(&bt, scale * tcount); + bintime2timespec(&bt, &ts); + hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec); + } +#endif + + /* Wakeup anyone sleeping in pps_fetch(). */ + wakeup(pps); +} + +/* + * Timecounters need to be updated every so often to prevent the hardware + * counter from overflowing. Updating also recalculates the cached values + * used by the get*() family of functions, so their precision depends on + * the update frequency. + */ + +static int tc_tick; +SYSCTL_INT(_kern_timecounter, OID_AUTO, tick, CTLFLAG_RD, &tc_tick, 0, + "Approximate number of hardclock ticks in a millisecond"); + +void +tc_ticktock(int cnt) +{ + static int count; + + count += cnt; + if (count < tc_tick) + return; + count = 0; + tc_windup(); +} + +static void __inline +tc_adjprecision(void) +{ + int t; + + if (tc_timepercentage > 0) { + t = (99 + tc_timepercentage) / tc_timepercentage; + tc_precexp = fls(t + (t >> 1)) - 1; + FREQ2BT(hz / tc_tick, &bt_timethreshold); + FREQ2BT(hz, &bt_tickthreshold); + bintime_shift(&bt_timethreshold, tc_precexp); + bintime_shift(&bt_tickthreshold, tc_precexp); + } else { + tc_precexp = 31; + bt_timethreshold.sec = INT_MAX; + bt_timethreshold.frac = ~(uint64_t)0; + bt_tickthreshold = bt_timethreshold; + } + sbt_timethreshold = bttosbt(bt_timethreshold); + sbt_tickthreshold = bttosbt(bt_tickthreshold); +} + +static int +sysctl_kern_timecounter_adjprecision(SYSCTL_HANDLER_ARGS) +{ + int error, val; + + val = tc_timepercentage; + error = sysctl_handle_int(oidp, &val, 0, req); + if (error != 0 || req->newptr == NULL) + return (error); + tc_timepercentage = val; + if (cold) + goto done; + tc_adjprecision(); +done: + return (0); +} + +static void +inittimecounter(void *dummy) +{ + u_int p; + int tick_rate; + + /* + * Set the initial timeout to + * max(1, ). + * People should probably not use the sysctl to set the timeout + * to smaller than its inital value, since that value is the + * smallest reasonable one. If they want better timestamps they + * should use the non-"get"* functions. + */ + if (hz > 1000) + tc_tick = (hz + 500) / 1000; + else + tc_tick = 1; + tc_adjprecision(); + FREQ2BT(hz, &tick_bt); + tick_sbt = bttosbt(tick_bt); + tick_rate = hz / tc_tick; + FREQ2BT(tick_rate, &tc_tick_bt); + tc_tick_sbt = bttosbt(tc_tick_bt); + p = (tc_tick * 1000000) / hz; + printf("Timecounters tick every %d.%03u msec\n", p / 1000, p % 1000); + +#ifdef FFCLOCK + ffclock_init(); +#endif + /* warm up new timecounter (again) and get rolling. */ + (void)timecounter->tc_get_timecount(timecounter); + (void)timecounter->tc_get_timecount(timecounter); + tc_windup(); +} + +SYSINIT(timecounter, SI_SUB_CLOCKS, SI_ORDER_SECOND, inittimecounter, NULL); + +/* Cpu tick handling -------------------------------------------------*/ + +static int cpu_tick_variable; +static uint64_t cpu_tick_frequency; + +static uint64_t +tc_cpu_ticks(void) +{ + static uint64_t base; + static unsigned last; + unsigned u; + struct timecounter *tc; + + tc = timehands->th_counter; + u = tc->tc_get_timecount(tc) & tc->tc_counter_mask; + if (u < last) + base += (uint64_t)tc->tc_counter_mask + 1; + last = u; + return (u + base); +} + +void +cpu_tick_calibration(void) +{ + static time_t last_calib; + + if (time_uptime != last_calib && !(time_uptime & 0xf)) { + cpu_tick_calibrate(0); + last_calib = time_uptime; + } +} + +/* + * This function gets called every 16 seconds on only one designated + * CPU in the system from hardclock() via cpu_tick_calibration()(). + * + * Whenever the real time clock is stepped we get called with reset=1 + * to make sure we handle suspend/resume and similar events correctly. + */ + +static void +cpu_tick_calibrate(int reset) +{ + static uint64_t c_last; + uint64_t c_this, c_delta; + static struct bintime t_last; + struct bintime t_this, t_delta; + uint32_t divi; + + if (reset) { + /* The clock was stepped, abort & reset */ + t_last.sec = 0; + return; + } + + /* we don't calibrate fixed rate cputicks */ + if (!cpu_tick_variable) + return; + + getbinuptime(&t_this); + c_this = cpu_ticks(); + if (t_last.sec != 0) { + c_delta = c_this - c_last; + t_delta = t_this; + bintime_sub(&t_delta, &t_last); + /* + * Headroom: + * 2^(64-20) / 16[s] = + * 2^(44) / 16[s] = + * 17.592.186.044.416 / 16 = + * 1.099.511.627.776 [Hz] + */ + divi = t_delta.sec << 20; + divi |= t_delta.frac >> (64 - 20); + c_delta <<= 20; + c_delta /= divi; + if (c_delta > cpu_tick_frequency) { + if (0 && bootverbose) + printf("cpu_tick increased to %ju Hz\n", + c_delta); + cpu_tick_frequency = c_delta; + } + } + c_last = c_this; + t_last = t_this; +} + +void +set_cputicker(cpu_tick_f *func, uint64_t freq, unsigned var) +{ + + if (func == NULL) { + cpu_ticks = tc_cpu_ticks; + } else { + cpu_tick_frequency = freq; + cpu_tick_variable = var; + cpu_ticks = func; + } +} + +uint64_t +cpu_tickrate(void) +{ + + if (cpu_ticks == tc_cpu_ticks) + return (tc_getfrequency()); + return (cpu_tick_frequency); +} + +/* + * We need to be slightly careful converting cputicks to microseconds. + * There is plenty of margin in 64 bits of microseconds (half a million + * years) and in 64 bits at 4 GHz (146 years), but if we do a multiply + * before divide conversion (to retain precision) we find that the + * margin shrinks to 1.5 hours (one millionth of 146y). + * With a three prong approach we never lose significant bits, no + * matter what the cputick rate and length of timeinterval is. + */ + +uint64_t +cputick2usec(uint64_t tick) +{ + + if (tick > 18446744073709551LL) /* floor(2^64 / 1000) */ + return (tick / (cpu_tickrate() / 1000000LL)); + else if (tick > 18446744073709LL) /* floor(2^64 / 1000000) */ + return ((tick * 1000LL) / (cpu_tickrate() / 1000LL)); + else + return ((tick * 1000000LL) / cpu_tickrate()); +} + +cpu_tick_f *cpu_ticks = tc_cpu_ticks; + +static int vdso_th_enable = 1; +static int +sysctl_fast_gettime(SYSCTL_HANDLER_ARGS) +{ + int old_vdso_th_enable, error; + + old_vdso_th_enable = vdso_th_enable; + error = sysctl_handle_int(oidp, &old_vdso_th_enable, 0, req); + if (error != 0) + return (error); + vdso_th_enable = old_vdso_th_enable; + return (0); +} +SYSCTL_PROC(_kern_timecounter, OID_AUTO, fast_gettime, + CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, + NULL, 0, sysctl_fast_gettime, "I", "Enable fast time of day"); + +uint32_t +tc_fill_vdso_timehands(struct vdso_timehands *vdso_th) +{ + struct timehands *th; + uint32_t enabled; + + th = timehands; + vdso_th->th_algo = VDSO_TH_ALGO_1; + vdso_th->th_scale = th->th_scale; + vdso_th->th_offset_count = th->th_offset_count; + vdso_th->th_counter_mask = th->th_counter->tc_counter_mask; + vdso_th->th_offset = th->th_offset; + vdso_th->th_boottime = boottimebin; + enabled = cpu_fill_vdso_timehands(vdso_th, th->th_counter); + if (!vdso_th_enable) + enabled = 0; + return (enabled); +} + +#ifdef COMPAT_FREEBSD32 +uint32_t +tc_fill_vdso_timehands32(struct vdso_timehands32 *vdso_th32) +{ + struct timehands *th; + uint32_t enabled; + + th = timehands; + vdso_th32->th_algo = VDSO_TH_ALGO_1; + *(uint64_t *)&vdso_th32->th_scale[0] = th->th_scale; + vdso_th32->th_offset_count = th->th_offset_count; + vdso_th32->th_counter_mask = th->th_counter->tc_counter_mask; + vdso_th32->th_offset.sec = th->th_offset.sec; + *(uint64_t *)&vdso_th32->th_offset.frac[0] = th->th_offset.frac; + vdso_th32->th_boottime.sec = boottimebin.sec; + *(uint64_t *)&vdso_th32->th_boottime.frac[0] = boottimebin.frac; + enabled = cpu_fill_vdso_timehands32(vdso_th32, th->th_counter); + if (!vdso_th_enable) + enabled = 0; + return (enabled); +} +#endif -- cgit v1.2.3