/*- * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * William Jolitz and Don Ahn. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)clock.c 7.2 (Berkeley) 5/12/91 */ #include __FBSDID("$FreeBSD$"); /* #define DELAYDEBUG */ /* * Routines to handle clock hardware. */ #include "opt_ddb.h" #include "opt_clock.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(SMP) #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 32-bit time_t's can't reach leap years before 1904 or after 2036, so we * can use a simple formula for leap years. */ #define LEAPYEAR(y) (!((y) % 4)) #define DAYSPERYEAR (28+30*4+31*7) #ifndef TIMER_FREQ #define TIMER_FREQ 1193182 #endif #ifdef CYC2NS_SCALE_FACTOR #undef CYC2NS_SCALE_FACTOR #endif #define CYC2NS_SCALE_FACTOR 10 /* Values for timerX_state: */ #define RELEASED 0 #define RELEASE_PENDING 1 #define ACQUIRED 2 #define ACQUIRE_PENDING 3 struct mtx clock_lock; #define RTC_LOCK_INIT \ mtx_init(&clock_lock, "clk", NULL, MTX_SPIN | MTX_NOPROFILE) #define RTC_LOCK mtx_lock_spin(&clock_lock) #define RTC_UNLOCK mtx_unlock_spin(&clock_lock) int adjkerntz; /* local offset from GMT in seconds */ int clkintr_pending; int pscnt = 1; int psdiv = 1; int wall_cmos_clock; u_int timer_freq = TIMER_FREQ; static int independent_wallclock; static int xen_disable_rtc_set; static u_long cyc2ns_scale; static struct timespec shadow_tv; static uint32_t shadow_tv_version; /* XXX: lazy locking */ static uint64_t processed_system_time; /* stime (ns) at last processing. */ static const u_char daysinmonth[] = {31,28,31,30,31,30,31,31,30,31,30,31}; SYSCTL_INT(_machdep, OID_AUTO, independent_wallclock, CTLFLAG_RW, &independent_wallclock, 0, ""); SYSCTL_INT(_machdep, OID_AUTO, xen_disable_rtc_set, CTLFLAG_RW, &xen_disable_rtc_set, 1, ""); #define do_div(n,base) ({ \ unsigned long __upper, __low, __high, __mod, __base; \ __base = (base); \ __asm("":"=a" (__low), "=d" (__high):"A" (n)); \ __upper = __high; \ if (__high) { \ __upper = __high % (__base); \ __high = __high / (__base); \ } \ __asm("divl %2":"=a" (__low), "=d" (__mod):"rm" (__base), "0" (__low), "1" (__upper)); \ __asm("":"=A" (n):"a" (__low),"d" (__high)); \ __mod; \ }) #define NS_PER_TICK (1000000000ULL/hz) #define rdtscll(val) \ __asm__ __volatile__("rdtsc" : "=A" (val)) /* convert from cycles(64bits) => nanoseconds (64bits) * basic equation: * ns = cycles / (freq / ns_per_sec) * ns = cycles * (ns_per_sec / freq) * ns = cycles * (10^9 / (cpu_mhz * 10^6)) * ns = cycles * (10^3 / cpu_mhz) * * Then we use scaling math (suggested by george@mvista.com) to get: * ns = cycles * (10^3 * SC / cpu_mhz) / SC * ns = cycles * cyc2ns_scale / SC * * And since SC is a constant power of two, we can convert the div * into a shift. * -johnstul@us.ibm.com "math is hard, lets go shopping!" */ static inline void set_cyc2ns_scale(unsigned long cpu_mhz) { cyc2ns_scale = (1000 << CYC2NS_SCALE_FACTOR)/cpu_mhz; } static inline unsigned long long cycles_2_ns(unsigned long long cyc) { return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR; } /* * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, * yielding a 64-bit result. */ static inline uint64_t scale_delta(uint64_t delta, uint32_t mul_frac, int shift) { uint64_t product; uint32_t tmp1, tmp2; if ( shift < 0 ) delta >>= -shift; else delta <<= shift; __asm__ ( "mul %5 ; " "mov %4,%%eax ; " "mov %%edx,%4 ; " "mul %5 ; " "xor %5,%5 ; " "add %4,%%eax ; " "adc %5,%%edx ; " : "=A" (product), "=r" (tmp1), "=r" (tmp2) : "a" ((uint32_t)delta), "1" ((uint32_t)(delta >> 32)), "2" (mul_frac) ); return product; } static uint64_t get_nsec_offset(struct shadow_time_info *shadow) { uint64_t now, delta; rdtscll(now); delta = now - shadow->tsc_timestamp; return scale_delta(delta, shadow->tsc_to_nsec_mul, shadow->tsc_shift); } static void update_wallclock(void) { shared_info_t *s = HYPERVISOR_shared_info; do { shadow_tv_version = s->wc_version; rmb(); shadow_tv.tv_sec = s->wc_sec; shadow_tv.tv_nsec = s->wc_nsec; rmb(); } while ((s->wc_version & 1) | (shadow_tv_version ^ s->wc_version)); } static void add_uptime_to_wallclock(void) { struct timespec ut; xen_fetch_uptime(&ut); timespecadd(&shadow_tv, &ut); } /* * Reads a consistent set of time-base values from Xen, into a shadow data * area. Must be called with the xtime_lock held for writing. */ static void __get_time_values_from_xen(void) { shared_info_t *s = HYPERVISOR_shared_info; struct vcpu_time_info *src; struct shadow_time_info *dst; uint32_t pre_version, post_version; src = &s->vcpu_info[smp_processor_id()].time; dst = &per_cpu(shadow_time, smp_processor_id()); spinlock_enter(); do { pre_version = dst->version = src->version; rmb(); dst->tsc_timestamp = src->tsc_timestamp; dst->system_timestamp = src->system_time; dst->tsc_to_nsec_mul = src->tsc_to_system_mul; dst->tsc_shift = src->tsc_shift; rmb(); post_version = src->version; } while ((pre_version & 1) | (pre_version ^ post_version)); dst->tsc_to_usec_mul = dst->tsc_to_nsec_mul / 1000; spinlock_exit(); } static inline int time_values_up_to_date(int cpu) { struct vcpu_time_info *src; struct shadow_time_info *dst; src = &HYPERVISOR_shared_info->vcpu_info[cpu].time; dst = &per_cpu(shadow_time, cpu); rmb(); return (dst->version == src->version); } static unsigned xen_get_timecount(struct timecounter *tc); static struct timecounter xen_timecounter = { xen_get_timecount, /* get_timecount */ 0, /* no poll_pps */ ~0u, /* counter_mask */ 0, /* frequency */ "ixen", /* name */ 0 /* quality */ }; static int clkintr(void *arg) { int64_t delta_cpu, delta; struct trapframe *frame = (struct trapframe *)arg; int cpu = smp_processor_id(); struct shadow_time_info *shadow = &per_cpu(shadow_time, cpu); do { __get_time_values_from_xen(); delta = delta_cpu = shadow->system_timestamp + get_nsec_offset(shadow); delta -= processed_system_time; delta_cpu -= per_cpu(processed_system_time, cpu); } while (!time_values_up_to_date(cpu)); if (unlikely(delta < (int64_t)0) || unlikely(delta_cpu < (int64_t)0)) { printf("Timer ISR: Time went backwards: %lld\n", delta); return (FILTER_HANDLED); } /* Process elapsed ticks since last call. */ while (delta >= NS_PER_TICK) { delta -= NS_PER_TICK; processed_system_time += NS_PER_TICK; per_cpu(processed_system_time, cpu) += NS_PER_TICK; if (PCPU_GET(cpuid) == 0) hardclock(TRAPF_USERMODE(frame), TRAPF_PC(frame)); else hardclock_cpu(TRAPF_USERMODE(frame)); } /* * Take synchronised time from Xen once a minute if we're not * synchronised ourselves, and we haven't chosen to keep an independent * time base. */ if (shadow_tv_version != HYPERVISOR_shared_info->wc_version && !independent_wallclock) { printf("[XEN] hypervisor wallclock nudged; nudging TOD.\n"); update_wallclock(); add_uptime_to_wallclock(); tc_setclock(&shadow_tv); } /* XXX TODO */ return (FILTER_HANDLED); } static uint32_t getit(void) { struct shadow_time_info *shadow; uint64_t time; uint32_t local_time_version; shadow = &per_cpu(shadow_time, smp_processor_id()); do { local_time_version = shadow->version; barrier(); time = shadow->system_timestamp + get_nsec_offset(shadow); if (!time_values_up_to_date(smp_processor_id())) __get_time_values_from_xen(/*cpu */); barrier(); } while (local_time_version != shadow->version); return (time); } /* * XXX: timer needs more SMP work. */ void i8254_init(void) { RTC_LOCK_INIT; } /* * Wait "n" microseconds. * Relies on timer 1 counting down from (timer_freq / hz) * Note: timer had better have been programmed before this is first used! */ void DELAY(int n) { int delta, ticks_left; uint32_t tick, prev_tick; #ifdef DELAYDEBUG int getit_calls = 1; int n1; static int state = 0; if (state == 0) { state = 1; for (n1 = 1; n1 <= 10000000; n1 *= 10) DELAY(n1); state = 2; } if (state == 1) printf("DELAY(%d)...", n); #endif /* * Read the counter first, so that the rest of the setup overhead is * counted. Guess the initial overhead is 20 usec (on most systems it * takes about 1.5 usec for each of the i/o's in getit(). The loop * takes about 6 usec on a 486/33 and 13 usec on a 386/20. The * multiplications and divisions to scale the count take a while). * * However, if ddb is active then use a fake counter since reading * the i8254 counter involves acquiring a lock. ddb must not go * locking for many reasons, but it calls here for at least atkbd * input. */ prev_tick = getit(); n -= 0; /* XXX actually guess no initial overhead */ /* * Calculate (n * (timer_freq / 1e6)) without using floating point * and without any avoidable overflows. */ if (n <= 0) ticks_left = 0; else if (n < 256) /* * Use fixed point to avoid a slow division by 1000000. * 39099 = 1193182 * 2^15 / 10^6 rounded to nearest. * 2^15 is the first power of 2 that gives exact results * for n between 0 and 256. */ ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15; else /* * Don't bother using fixed point, although gcc-2.7.2 * generates particularly poor code for the long long * division, since even the slow way will complete long * before the delay is up (unless we're interrupted). */ ticks_left = ((u_int)n * (long long)timer_freq + 999999) / 1000000; while (ticks_left > 0) { tick = getit(); #ifdef DELAYDEBUG ++getit_calls; #endif delta = tick - prev_tick; prev_tick = tick; if (delta < 0) { /* * Guard against timer0_max_count being wrong. * This shouldn't happen in normal operation, * but it may happen if set_timer_freq() is * traced. */ /* delta += timer0_max_count; ??? */ if (delta < 0) delta = 0; } ticks_left -= delta; } #ifdef DELAYDEBUG if (state == 1) printf(" %d calls to getit() at %d usec each\n", getit_calls, (n + 5) / getit_calls); #endif } /* * Restore all the timers non-atomically (XXX: should be atomically). * * This function is called from pmtimer_resume() to restore all the timers. * This should not be necessary, but there are broken laptops that do not * restore all the timers on resume. */ void timer_restore(void) { /* Get timebases for new environment. */ __get_time_values_from_xen(); /* Reset our own concept of passage of system time. */ processed_system_time = per_cpu(shadow_time, 0).system_timestamp; per_cpu(processed_system_time, 0) = processed_system_time; } void startrtclock() { unsigned long long alarm; uint64_t __cpu_khz; uint32_t cpu_khz; struct vcpu_time_info *info; /* initialize xen values */ __get_time_values_from_xen(); processed_system_time = per_cpu(shadow_time, 0).system_timestamp; per_cpu(processed_system_time, 0) = processed_system_time; __cpu_khz = 1000000ULL << 32; info = &HYPERVISOR_shared_info->vcpu_info[0].time; do_div(__cpu_khz, info->tsc_to_system_mul); if ( info->tsc_shift < 0 ) cpu_khz = __cpu_khz << -info->tsc_shift; else cpu_khz = __cpu_khz >> info->tsc_shift; printf("Xen reported: %u.%03u MHz processor.\n", cpu_khz / 1000, cpu_khz % 1000); /* (10^6 * 2^32) / cpu_hz = (10^3 * 2^32) / cpu_khz = (2^32 * 1 / (clocks/us)) */ set_cyc2ns_scale(cpu_khz/1000); tsc_freq = cpu_khz * 1000; timer_freq = xen_timecounter.tc_frequency = 1000000000LL; tc_init(&xen_timecounter); rdtscll(alarm); } /* * RTC support routines */ static __inline int readrtc(int port) { return(bcd2bin(rtcin(port))); } #ifdef XEN_PRIVILEGED_GUEST /* * Initialize the time of day register, based on the time base which is, e.g. * from a filesystem. */ static void domu_inittodr(time_t base) { unsigned long sec; int s, y; struct timespec ts; update_wallclock(); add_uptime_to_wallclock(); RTC_LOCK; if (base) { ts.tv_sec = base; ts.tv_nsec = 0; tc_setclock(&ts); } sec += tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0); y = time_second - shadow_tv.tv_sec; if (y <= -2 || y >= 2) { /* badly off, adjust it */ tc_setclock(&shadow_tv); } RTC_UNLOCK; } /* * Write system time back to RTC. */ static void domu_resettodr(void) { unsigned long tm; int s; dom0_op_t op; struct shadow_time_info *shadow; shadow = &per_cpu(shadow_time, smp_processor_id()); if (xen_disable_rtc_set) return; s = splclock(); tm = time_second; splx(s); tm -= tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0); if ((xen_start_info->flags & SIF_INITDOMAIN) && !independent_wallclock) { op.cmd = DOM0_SETTIME; op.u.settime.secs = tm; op.u.settime.nsecs = 0; op.u.settime.system_time = shadow->system_timestamp; HYPERVISOR_dom0_op(&op); update_wallclock(); add_uptime_to_wallclock(); } else if (independent_wallclock) { /* notyet */ ; } } /* * Initialize the time of day register, based on the time base which is, e.g. * from a filesystem. */ void inittodr(time_t base) { unsigned long sec, days; int year, month; int y, m, s; struct timespec ts; if (!(xen_start_info->flags & SIF_INITDOMAIN)) { domu_inittodr(base); return; } if (base) { s = splclock(); ts.tv_sec = base; ts.tv_nsec = 0; tc_setclock(&ts); splx(s); } /* Look if we have a RTC present and the time is valid */ if (!(rtcin(RTC_STATUSD) & RTCSD_PWR)) goto wrong_time; /* wait for time update to complete */ /* If RTCSA_TUP is zero, we have at least 244us before next update */ s = splhigh(); while (rtcin(RTC_STATUSA) & RTCSA_TUP) { splx(s); s = splhigh(); } days = 0; #ifdef USE_RTC_CENTURY year = readrtc(RTC_YEAR) + readrtc(RTC_CENTURY) * 100; #else year = readrtc(RTC_YEAR) + 1900; if (year < 1970) year += 100; #endif if (year < 1970) { splx(s); goto wrong_time; } month = readrtc(RTC_MONTH); for (m = 1; m < month; m++) days += daysinmonth[m-1]; if ((month > 2) && LEAPYEAR(year)) days ++; days += readrtc(RTC_DAY) - 1; for (y = 1970; y < year; y++) days += DAYSPERYEAR + LEAPYEAR(y); sec = ((( days * 24 + readrtc(RTC_HRS)) * 60 + readrtc(RTC_MIN)) * 60 + readrtc(RTC_SEC)); /* sec now contains the number of seconds, since Jan 1 1970, in the local time zone */ sec += tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0); y = time_second - sec; if (y <= -2 || y >= 2) { /* badly off, adjust it */ ts.tv_sec = sec; ts.tv_nsec = 0; tc_setclock(&ts); } splx(s); return; wrong_time: printf("Invalid time in real time clock.\n"); printf("Check and reset the date immediately!\n"); } /* * Write system time back to RTC */ void resettodr() { unsigned long tm; int y, m, s; if (!(xen_start_info->flags & SIF_INITDOMAIN)) { domu_resettodr(); return; } if (xen_disable_rtc_set) return; s = splclock(); tm = time_second; splx(s); /* Disable RTC updates and interrupts. */ writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR); /* Calculate local time to put in RTC */ tm -= tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0); writertc(RTC_SEC, bin2bcd(tm%60)); tm /= 60; /* Write back Seconds */ writertc(RTC_MIN, bin2bcd(tm%60)); tm /= 60; /* Write back Minutes */ writertc(RTC_HRS, bin2bcd(tm%24)); tm /= 24; /* Write back Hours */ /* We have now the days since 01-01-1970 in tm */ writertc(RTC_WDAY, (tm + 4) % 7 + 1); /* Write back Weekday */ for (y = 1970, m = DAYSPERYEAR + LEAPYEAR(y); tm >= m; y++, m = DAYSPERYEAR + LEAPYEAR(y)) tm -= m; /* Now we have the years in y and the day-of-the-year in tm */ writertc(RTC_YEAR, bin2bcd(y%100)); /* Write back Year */ #ifdef USE_RTC_CENTURY writertc(RTC_CENTURY, bin2bcd(y/100)); /* ... and Century */ #endif for (m = 0; ; m++) { int ml; ml = daysinmonth[m]; if (m == 1 && LEAPYEAR(y)) ml++; if (tm < ml) break; tm -= ml; } writertc(RTC_MONTH, bin2bcd(m + 1)); /* Write back Month */ writertc(RTC_DAY, bin2bcd(tm + 1)); /* Write back Month Day */ /* Reenable RTC updates and interrupts. */ writertc(RTC_STATUSB, RTCSB_24HR); rtcin(RTC_INTR); } #endif static struct vcpu_set_periodic_timer xen_set_periodic_tick; /* * Start clocks running. */ void cpu_initclocks(void) { unsigned int time_irq; int error; xen_set_periodic_tick.period_ns = NS_PER_TICK; HYPERVISOR_vcpu_op(VCPUOP_set_periodic_timer, 0, &xen_set_periodic_tick); error = bind_virq_to_irqhandler(VIRQ_TIMER, 0, "clk", clkintr, NULL, NULL, INTR_TYPE_CLK | INTR_FAST, &time_irq); if (error) panic("failed to register clock interrupt\n"); /* should fast clock be enabled ? */ } int ap_cpu_initclocks(int cpu) { unsigned int time_irq; int error; xen_set_periodic_tick.period_ns = NS_PER_TICK; HYPERVISOR_vcpu_op(VCPUOP_set_periodic_timer, cpu, &xen_set_periodic_tick); error = bind_virq_to_irqhandler(VIRQ_TIMER, 0, "clk", clkintr, NULL, NULL, INTR_TYPE_CLK | INTR_FAST, &time_irq); if (error) panic("failed to register clock interrupt\n"); return (0); } void cpu_startprofclock(void) { printf("cpu_startprofclock: profiling clock is not supported\n"); } void cpu_stopprofclock(void) { printf("cpu_stopprofclock: profiling clock is not supported\n"); } #define NSEC_PER_USEC 1000 static uint32_t xen_get_timecount(struct timecounter *tc) { uint64_t clk; struct shadow_time_info *shadow; shadow = &per_cpu(shadow_time, smp_processor_id()); __get_time_values_from_xen(); clk = shadow->system_timestamp + get_nsec_offset(shadow); return (uint32_t)(clk); } /* Return system time offset by ticks */ uint64_t get_system_time(int ticks) { return processed_system_time + (ticks * NS_PER_TICK); } /* * Track behavior of cur_timer->get_offset() functionality in timer_tsc.c */ /* Convert jiffies to system time. */ static uint64_t ticks_to_system_time(int newticks) { int delta; uint64_t st; delta = newticks - ticks; if (delta < 1) { /* Triggers in some wrap-around cases, * but that's okay: * we just end up with a shorter timeout. */ st = processed_system_time + NS_PER_TICK; } else if (((unsigned int)delta >> (BITS_PER_LONG-3)) != 0) { /* Very long timeout means there is no pending timer. * We indicate this to Xen by passing zero timeout. */ st = 0; } else { st = processed_system_time + delta * (uint64_t)NS_PER_TICK; } return (st); } void idle_block(void) { uint64_t timeout; timeout = ticks_to_system_time(ticks + 1) + NS_PER_TICK/2; __get_time_values_from_xen(); PANIC_IF(HYPERVISOR_set_timer_op(timeout) != 0); HYPERVISOR_sched_op(SCHEDOP_block, 0); } int timer_spkr_acquire(void) { return (0); } int timer_spkr_release(void) { return (0); } void timer_spkr_setfreq(int freq) { }