freebsd-dev/sys/i386/xen/clock.c
Bryan Venteicher d3ccddf3ce Generalized parts of the XEN timer code into a generic pvclock
KVM clock shares the same data structures between the guest and the host
as Xen so it makes sense to just have a single copy of this code.

Differential Revision: https://reviews.freebsd.org/D1429
Reviewed by:	royger (eariler version)
MFC after:	1 month
2015-02-04 08:26:43 +00:00

571 lines
13 KiB
C

/*-
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/* #define DELAYDEBUG */
/*
* Routines to handle clock hardware.
*/
#include "opt_ddb.h"
#include "opt_clock.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/clock.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/sysctl.h>
#include <sys/cons.h>
#include <sys/power.h>
#include <machine/clock.h>
#include <machine/cputypes.h>
#include <machine/frame.h>
#include <machine/intr_machdep.h>
#include <machine/md_var.h>
#include <machine/psl.h>
#include <machine/pvclock.h>
#if defined(SMP)
#include <machine/smp.h>
#endif
#include <machine/specialreg.h>
#include <machine/timerreg.h>
#include <x86/isa/icu.h>
#include <isa/isareg.h>
#include <isa/rtc.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/pmap.h>
#include <xen/hypervisor.h>
#include <xen/xen-os.h>
#include <machine/xen/xenfunc.h>
#include <xen/interface/vcpu.h>
#include <machine/cpu.h>
#include <xen/xen_intr.h>
/*
* 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)
#define NS_PER_TICK (1000000000ULL/hz)
int adjkerntz; /* local offset from UTC in seconds */
int clkintr_pending;
int pscnt = 1;
int psdiv = 1;
int wall_cmos_clock;
u_int timer_freq = TIMER_FREQ;
static u_long cyc2ns_scale;
static uint64_t processed_system_time; /* stime (ns) at last processing. */
#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; \
})
/* 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);
}
static uint32_t
getit(void)
{
return (pvclock_get_last_cycles());
}
/*
* 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
i8254_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
}
void
startrtclock()
{
uint64_t __cpu_khz;
uint32_t cpu_khz;
struct vcpu_time_info *info;
__cpu_khz = 1000000ULL << 32;
info = &HYPERVISOR_shared_info->vcpu_info[0].time;
(void)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;
}
/*
* 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;
struct pcpu *pc;
pc = pcpu_find(smp_processor_id());
shadow = &pc->pc_shadow_time;
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
/*
* Start clocks running.
*/
void
cpu_initclocks(void)
{
cpu_initclocks_bsp();
}
/* Return system time offset by ticks */
uint64_t
get_system_time(int ticks)
{
return (processed_system_time + (ticks * NS_PER_TICK));
}
int
timer_spkr_acquire(void)
{
return (0);
}
int
timer_spkr_release(void)
{
return (0);
}
void
timer_spkr_setfreq(int freq)
{
}