mirror/freebsd
1
0
Fork 0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-24 11:29:10 +00:00
Code Issues Releases Activity
435929a84b
freebsd/sys/amd64/include/clock.h

112 lines
2.8 KiB
C
Raw Normal View History

Redo Kernel NTP PLL support, kernel side. This code is mostly taken from the 1.1 port (which was in turn taken from Dave Mills's kern.tar.Z example). A few significant differences: 1) ntp_gettime() is now a MIB variable rather than a system call. A few fiddles are done in libc to make it behave the same. 2) mono_time does not participate in the PLL adjustments. 3) A new interface has been defined (in <machine/clock.h>) for doing possibly machine-dependent things around the time of the clock update. This is used in Pentium kernels to disable interrupts, set `time', and reset the CPU cycle counter as quickly as possible to avoid jitter in microtime(). Measurements show an apparent resolution of a bit more than 8.14usec, which is reasonable given system-call overhead.
1994-09-18 20:40:01 +00:00
/*
* Kernel interface to machine-dependent clock driver.
* Garrett Wollman, September 1994.
* This file is in the public domain.
Fix Pentium CPU rate diagnosis: - Don't print out meaningless iCOMP numbers, those are for droids. - Use a shorter wait to determine clock rate to avoid deficiencies in DELAY(). - Use a fixed-point representation with 8 bits of fraction to store the rate and rationalize the variable name. It would be possible to use even more fraction if it turns out to be worthwhile (I rather doubt it). The question of source code arrangement remains unaddressed.
1995-11-29 19:57:22 +00:00
*
Don't include "opt_cpu.h" in <machine/clock.h>, since this breaks lkm's. The change breaks kern_clock.c; fix that temporarily by including "opt_cpu.h" there.
1996-10-10 10:25:26 +00:00
* $Id: clock.h,v 1.17 1996/10/09 19:47:26 bde Exp $
Redo Kernel NTP PLL support, kernel side. This code is mostly taken from the 1.1 port (which was in turn taken from Dave Mills's kern.tar.Z example). A few significant differences: 1) ntp_gettime() is now a MIB variable rather than a system call. A few fiddles are done in libc to make it behave the same. 2) mono_time does not participate in the PLL adjustments. 3) A new interface has been defined (in <machine/clock.h>) for doing possibly machine-dependent things around the time of the clock update. This is used in Pentium kernels to disable interrupts, set `time', and reset the CPU cycle counter as quickly as possible to avoid jitter in microtime(). Measurements show an apparent resolution of a bit more than 8.14usec, which is reasonable given system-call overhead.
1994-09-18 20:40:01 +00:00
*/
#ifndef _MACHINE_CLOCK_H_
Declare the full uglyness of the interfaces to the clock driver (except things declared in machine-independent files).
1994-11-05 22:51:17 +00:00
#define _MACHINE_CLOCK_H_
Redo Kernel NTP PLL support, kernel side. This code is mostly taken from the 1.1 port (which was in turn taken from Dave Mills's kern.tar.Z example). A few significant differences: 1) ntp_gettime() is now a MIB variable rather than a system call. A few fiddles are done in libc to make it behave the same. 2) mono_time does not participate in the PLL adjustments. 3) A new interface has been defined (in <machine/clock.h>) for doing possibly machine-dependent things around the time of the clock update. This is used in Pentium kernels to disable interrupts, set `time', and reset the CPU cycle counter as quickly as possible to avoid jitter in microtime(). Measurements show an apparent resolution of a bit more than 8.14usec, which is reasonable given system-call overhead.
1994-09-18 20:40:01 +00:00
Add Pentium Pro CPU detection and special handling. For now, all the optimizations we have for 586s also apply to 686s...this will be fine- tuned in the future as appropriate.
1995-12-24 08:10:52 +00:00
#if defined(I586_CPU) || defined(I686_CPU)
Reduce jitter of Pentium microtime() implementation by letting the counter free-run and doing a subtract in microtime() rather than resetting the counter to zero at every clock tick. In combination with the changes to kern_clock.c, this should eliminate all the immediately obvious sources of systematic jitter in timekeeping on Pentium machines.
1995-10-12 20:39:49 +00:00
/*
* When we update the clock, we also update this bias value which is
* automatically subtracted in microtime(). We assume that CPU_THISTICKLEN()
* has been called at some point in the past, so that an appropriate value is
* set up in i586_last_tick. (This works even if we are not being called
* from hardclock because hardclock will have run before and will made the
* call.)
*/
Redo Kernel NTP PLL support, kernel side. This code is mostly taken from the 1.1 port (which was in turn taken from Dave Mills's kern.tar.Z example). A few significant differences: 1) ntp_gettime() is now a MIB variable rather than a system call. A few fiddles are done in libc to make it behave the same. 2) mono_time does not participate in the PLL adjustments. 3) A new interface has been defined (in <machine/clock.h>) for doing possibly machine-dependent things around the time of the clock update. This is used in Pentium kernels to disable interrupts, set `time', and reset the CPU cycle counter as quickly as possible to avoid jitter in microtime(). Measurements show an apparent resolution of a bit more than 8.14usec, which is reasonable given system-call overhead.
1994-09-18 20:40:01 +00:00
#define CPU_CLOCKUPDATE(otime, ntime) \
do { \
Eliminated i586_ctr_rate. Use i586_ctr_freq instead. Changed i586_ctr_bias from long long to u_int. Only the low 32 bits are used now that microtime uses a multiplication to do the scaling. Previously the high 32 bits had to match those of rdtsc() to prevent overflow traps and invalid timeval adjustments.
1996-08-02 21:16:13 +00:00
if (i586_ctr_freq != 0) { \
Reduce jitter of Pentium microtime() implementation by letting the counter free-run and doing a subtract in microtime() rather than resetting the counter to zero at every clock tick. In combination with the changes to kern_clock.c, this should eliminate all the immediately obvious sources of systematic jitter in timekeeping on Pentium machines.
1995-10-12 20:39:49 +00:00
disable_intr(); \
i586_ctr_bias = i586_last_tick; \
*(otime) = *(ntime); \
enable_intr(); \
Redo Kernel NTP PLL support, kernel side. This code is mostly taken from the 1.1 port (which was in turn taken from Dave Mills's kern.tar.Z example). A few significant differences: 1) ntp_gettime() is now a MIB variable rather than a system call. A few fiddles are done in libc to make it behave the same. 2) mono_time does not participate in the PLL adjustments. 3) A new interface has been defined (in <machine/clock.h>) for doing possibly machine-dependent things around the time of the clock update. This is used in Pentium kernels to disable interrupts, set `time', and reset the CPU cycle counter as quickly as possible to avoid jitter in microtime(). Measurements show an apparent resolution of a bit more than 8.14usec, which is reasonable given system-call overhead.
1994-09-18 20:40:01 +00:00
} else { \
*(otime) = *(ntime); \
} \
} while(0)
Reduce jitter of Pentium microtime() implementation by letting the counter free-run and doing a subtract in microtime() rather than resetting the counter to zero at every clock tick. In combination with the changes to kern_clock.c, this should eliminate all the immediately obvious sources of systematic jitter in timekeeping on Pentium machines.
1995-10-12 20:39:49 +00:00
#define CPU_THISTICKLEN(dflt) cpu_thisticklen(dflt)
Redo Kernel NTP PLL support, kernel side. This code is mostly taken from the 1.1 port (which was in turn taken from Dave Mills's kern.tar.Z example). A few significant differences: 1) ntp_gettime() is now a MIB variable rather than a system call. A few fiddles are done in libc to make it behave the same. 2) mono_time does not participate in the PLL adjustments. 3) A new interface has been defined (in <machine/clock.h>) for doing possibly machine-dependent things around the time of the clock update. This is used in Pentium kernels to disable interrupts, set `time', and reset the CPU cycle counter as quickly as possible to avoid jitter in microtime(). Measurements show an apparent resolution of a bit more than 8.14usec, which is reasonable given system-call overhead.
1994-09-18 20:40:01 +00:00
#else
#define CPU_CLOCKUPDATE(otime, ntime) \
(*(otime) = *(ntime))
Reduce jitter of Pentium microtime() implementation by letting the counter free-run and doing a subtract in microtime() rather than resetting the counter to zero at every clock tick. In combination with the changes to kern_clock.c, this should eliminate all the immediately obvious sources of systematic jitter in timekeeping on Pentium machines.
1995-10-12 20:39:49 +00:00
#define CPU_THISTICKLEN(dflt) dflt
Redo Kernel NTP PLL support, kernel side. This code is mostly taken from the 1.1 port (which was in turn taken from Dave Mills's kern.tar.Z example). A few significant differences: 1) ntp_gettime() is now a MIB variable rather than a system call. A few fiddles are done in libc to make it behave the same. 2) mono_time does not participate in the PLL adjustments. 3) A new interface has been defined (in <machine/clock.h>) for doing possibly machine-dependent things around the time of the clock update. This is used in Pentium kernels to disable interrupts, set `time', and reset the CPU cycle counter as quickly as possible to avoid jitter in microtime(). Measurements show an apparent resolution of a bit more than 8.14usec, which is reasonable given system-call overhead.
1994-09-18 20:40:01 +00:00
#endif
Fixed the machdep.i8254_freq and machdep.i586_freq sysctls. Writes were handled bogusly. Centralized the setting of all the frequency variables. Set these variables atomically. Some new ones aren't used yet.
1996-07-30 19:26:55 +00:00
#define I586_CTR_COMULTIPLIER_SHIFT 20
#define I586_CTR_MULTIPLIER_SHIFT 32
Fix Pentium CPU rate diagnosis: - Don't print out meaningless iCOMP numbers, those are for droids. - Use a shorter wait to determine clock rate to avoid deficiencies in DELAY(). - Use a fixed-point representation with 8 bits of fraction to store the rate and rationalize the variable name. It would be possible to use even more fraction if it turns out to be worthwhile (I rather doubt it). The question of source code arrangement remains unaddressed.
1995-11-29 19:57:22 +00:00
Declare the full uglyness of the interfaces to the clock driver (except things declared in machine-independent files).
1994-11-05 22:51:17 +00:00
#if defined(KERNEL) && !defined(LOCORE)
#include <sys/cdefs.h>
#include <machine/frame.h>
/*
* i386 to clock driver interface.
* XXX almost all of it is misplaced. i586 stuff is done in isa/clock.c
* and isa stuff is done in i386/microtime.s and i386/support.s.
*/
extern int adjkerntz;
extern int disable_rtc_set;
- add apm to the GENERIC kernel (disabled by default), and add some comments regarding apm to LINT - Disabled the statistics clock on machines which have an APM BIOS and have the options "APM_BROKEN_STATCLOCK" enabled (which is default in GENERIC now) - move around some of the code in clock.c dealing with the rtc to make it more obvios the effects of disabling the statistics clock Reviewed by: bde
1996-04-22 19:40:28 +00:00
extern int statclock_disable;
Add wall_cmos_clock sysctl variable, needed to manage adjkerntz even for UTC cmos clocks (needed for Local Timezone FSes)
1996-04-05 03:36:31 +00:00
extern int wall_cmos_clock;
Add Pentium Pro CPU detection and special handling. For now, all the optimizations we have for 586s also apply to 686s...this will be fine- tuned in the future as appropriate.
1995-12-24 08:10:52 +00:00
#if defined(I586_CPU) || defined(I686_CPU)
Eliminated i586_ctr_rate. Use i586_ctr_freq instead. Changed i586_ctr_bias from long long to u_int. Only the low 32 bits are used now that microtime uses a multiplication to do the scaling. Previously the high 32 bits had to match those of rdtsc() to prevent overflow traps and invalid timeval adjustments.
1996-08-02 21:16:13 +00:00
extern u_int i586_ctr_bias;
Fixed the machdep.i8254_freq and machdep.i586_freq sysctls. Writes were handled bogusly. Centralized the setting of all the frequency variables. Set these variables atomically. Some new ones aren't used yet.
1996-07-30 19:26:55 +00:00
extern u_int i586_ctr_comultiplier;
extern u_int i586_ctr_freq;
extern u_int i586_ctr_multiplier;
Reduce jitter of Pentium microtime() implementation by letting the counter free-run and doing a subtract in microtime() rather than resetting the counter to zero at every clock tick. In combination with the changes to kern_clock.c, this should eliminate all the immediately obvious sources of systematic jitter in timekeeping on Pentium machines.
1995-10-12 20:39:49 +00:00
extern long long i586_last_tick;
No longer use the cyclecounter to attempt to correct for late or missed clock interrupts. Keep a 1-in-16 smoothed average of the length of each tick. If the CPU speed is correctly diagnosed, this should give experienced users enough information to figure out a more suitable value for `tick'.
1996-01-30 18:56:47 +00:00
extern unsigned long i586_avg_tick;
Declare the full uglyness of the interfaces to the clock driver (except things declared in machine-independent files).
1994-11-05 22:51:17 +00:00
#endif
extern int timer0_max_count;
extern u_int timer0_overflow_threshold;
extern u_int timer0_prescaler_count;
Add Pentium Pro CPU detection and special handling. For now, all the optimizations we have for 586s also apply to 686s...this will be fine- tuned in the future as appropriate.
1995-12-24 08:10:52 +00:00
#if defined(I586_CPU) || defined(I686_CPU)
Reduce jitter of Pentium microtime() implementation by letting the counter free-run and doing a subtract in microtime() rather than resetting the counter to zero at every clock tick. In combination with the changes to kern_clock.c, this should eliminate all the immediately obvious sources of systematic jitter in timekeeping on Pentium machines.
1995-10-12 20:39:49 +00:00
static __inline u_long
cpu_thisticklen(u_long dflt)
{
long long old;
No longer use the cyclecounter to attempt to correct for late or missed clock interrupts. Keep a 1-in-16 smoothed average of the length of each tick. If the CPU speed is correctly diagnosed, this should give experienced users enough information to figure out a more suitable value for `tick'.
1996-01-30 18:56:47 +00:00
long len;
Added calibration the i8254 and the i586 clocks agains the RTC at boot time. The results are currently ignored unless certain temporary options are used. Added sysctls to support reading and writing the clock frequency variables (not the frequencies themselves). Writing is supposed to atomically adjust all related variables. machdep.c: Fixed spelling of a function name in a comment so that I can log this message which should have been with the previous commit. Initialize `cpu_class' earlier so that it can be used in startrtclock() instead of in calibrate_cyclecounter() (which no longer exists). Removed range checking of `cpu'. It is always initialized to CPU_XXX so it is less likely to be out of bounds than most variables. clock.h: Removed I586_CYCLECTR(). Use rdtsc() instead. clock.c: TIMER_FREQ is now a variable timer_freq that defaults to the old value of TIMER_FREQ. #define'ing TIMER_FREQ should still work and may be the best way of setting the frequency. Calibration involves counting cycles while watching the RTC for one second. This gives values correct to within (a few ppm) + (the innaccuracy of the RTC) on my systems.
1996-05-01 08:39:02 +00:00
Eliminated i586_ctr_rate. Use i586_ctr_freq instead. Changed i586_ctr_bias from long long to u_int. Only the low 32 bits are used now that microtime uses a multiplication to do the scaling. Previously the high 32 bits had to match those of rdtsc() to prevent overflow traps and invalid timeval adjustments.
1996-08-02 21:16:13 +00:00
if (i586_ctr_freq != 0) {
Reduce jitter of Pentium microtime() implementation by letting the counter free-run and doing a subtract in microtime() rather than resetting the counter to zero at every clock tick. In combination with the changes to kern_clock.c, this should eliminate all the immediately obvious sources of systematic jitter in timekeeping on Pentium machines.
1995-10-12 20:39:49 +00:00
old = i586_last_tick;
Added calibration the i8254 and the i586 clocks agains the RTC at boot time. The results are currently ignored unless certain temporary options are used. Added sysctls to support reading and writing the clock frequency variables (not the frequencies themselves). Writing is supposed to atomically adjust all related variables. machdep.c: Fixed spelling of a function name in a comment so that I can log this message which should have been with the previous commit. Initialize `cpu_class' earlier so that it can be used in startrtclock() instead of in calibrate_cyclecounter() (which no longer exists). Removed range checking of `cpu'. It is always initialized to CPU_XXX so it is less likely to be out of bounds than most variables. clock.h: Removed I586_CYCLECTR(). Use rdtsc() instead. clock.c: TIMER_FREQ is now a variable timer_freq that defaults to the old value of TIMER_FREQ. #define'ing TIMER_FREQ should still work and may be the best way of setting the frequency. Calibration involves counting cycles while watching the RTC for one second. This gives values correct to within (a few ppm) + (the innaccuracy of the RTC) on my systems.
1996-05-01 08:39:02 +00:00
i586_last_tick = rdtsc();
Eliminated i586_ctr_rate. Use i586_ctr_freq instead. Changed i586_ctr_bias from long long to u_int. Only the low 32 bits are used now that microtime uses a multiplication to do the scaling. Previously the high 32 bits had to match those of rdtsc() to prevent overflow traps and invalid timeval adjustments.
1996-08-02 21:16:13 +00:00
len = ((i586_last_tick - old) * i586_ctr_multiplier)
>> I586_CTR_MULTIPLIER_SHIFT;
No longer use the cyclecounter to attempt to correct for late or missed clock interrupts. Keep a 1-in-16 smoothed average of the length of each tick. If the CPU speed is correctly diagnosed, this should give experienced users enough information to figure out a more suitable value for `tick'.
1996-01-30 18:56:47 +00:00
i586_avg_tick = i586_avg_tick * 15 / 16 + len / 16;
Reduce jitter of Pentium microtime() implementation by letting the counter free-run and doing a subtract in microtime() rather than resetting the counter to zero at every clock tick. In combination with the changes to kern_clock.c, this should eliminate all the immediately obvious sources of systematic jitter in timekeeping on Pentium machines.
1995-10-12 20:39:49 +00:00
}
No longer use the cyclecounter to attempt to correct for late or missed clock interrupts. Keep a 1-in-16 smoothed average of the length of each tick. If the CPU speed is correctly diagnosed, this should give experienced users enough information to figure out a more suitable value for `tick'.
1996-01-30 18:56:47 +00:00
return dflt;
Reduce jitter of Pentium microtime() implementation by letting the counter free-run and doing a subtract in microtime() rather than resetting the counter to zero at every clock tick. In combination with the changes to kern_clock.c, this should eliminate all the immediately obvious sources of systematic jitter in timekeeping on Pentium machines.
1995-10-12 20:39:49 +00:00
}
#endif
Declare the full uglyness of the interfaces to the clock driver (except things declared in machine-independent files).
1994-11-05 22:51:17 +00:00
/*
* Driver to clock driver interface.
*/
void DELAY __P((int usec));
int acquire_timer0 __P((int rate,
void (*function)(struct clockframe *frame)));
int acquire_timer2 __P((int mode));
int release_timer0 __P((void));
int release_timer2 __P((void));
The Great PC98 Merge. All new code is "#ifdef PC98"ed so this should make no difference to PC/AT (and its clones) users. Ok'd by: core Submitted by: FreeBSD(98) development team
1996-06-14 11:02:28 +00:00
#ifndef PC98
Moved rtcin() to clock.c. Always delay using one inb(0x84) after each i/o in rtcin() - don't do this conditional on the bogus option DUMMY_NOPS not being defined. If you want an optionally slightly faster rtcin() again, then inline it and use a better named option or sysctl variable. It only needs to be fast in rtcintr().
1996-03-31 04:05:36 +00:00
int rtcin __P((int val));
The Great PC98 Merge. All new code is "#ifdef PC98"ed so this should make no difference to PC/AT (and its clones) users. Ok'd by: core Submitted by: FreeBSD(98) development team
1996-06-14 11:02:28 +00:00
#else
int acquire_timer1 __P((int mode));
int release_timer1 __P((void));
void rtc_serialcombit __P((int i));
void rtc_serialcom __P((int i));
void rtc_outb __P((int val));
#endif
Declare the full uglyness of the interfaces to the clock driver (except things declared in machine-independent files).
1994-11-05 22:51:17 +00:00
int sysbeep __P((int pitch, int period));
#endif /* KERNEL && !LOCORE */
#endif /* !_MACHINE_CLOCK_H_ */
Reference in New Issue Copy Permalink