Improved biasing of i586 clock by adjusting for hardclock() latency.
I decided to do this for every hardclock() call instead of lazily in microtime(). The lazy method is simpler but has more overhead if microtime() is called a lot. CPU_THISTICKLEN() is now a no-op and should probably go away. Previously it did nothing directly but had the side effect of setting i586_last_tick for CPU_CLOCKUPDATE() and i586_avg_tick for debugging. CPU_CLOCKUPDATE() now uses a better method and i586_avg_tick is too much trouble to maintain. Reduced nesting of #includes in the usual case. Increased nesting of #includes when CLOCK_HAIR is defined. This is a kludge to get typedefs for inline functions only when the inline functions are used. Normally only kern_clock.c defines this. kern_clock.c can't include the i386 headers directly. Removed unused LOCORE support.
This commit is contained in:
Bruce Evans
parent
22b9cd6f99
commit
835bd1ce62
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=19172
@ -3,48 +3,24 @@
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* Garrett Wollman, September 1994.
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* This file is in the public domain.
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*
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* $Id: clock.h,v 1.18 1996/10/10 10:25:26 bde Exp $
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* $Id: clock.h,v 1.19 1996/10/17 17:31:25 bde Exp $
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*/
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#ifndef _MACHINE_CLOCK_H_
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#define _MACHINE_CLOCK_H_
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#if defined(I586_CPU) || defined(I686_CPU)
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/*
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* When we update the clock, we also update this bias value which is
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* automatically subtracted in microtime(). We assume that CPU_THISTICKLEN()
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* has been called at some point in the past, so that an appropriate value is
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* set up in i586_last_tick. (This works even if we are not being called
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* from hardclock because hardclock will have run before and will made the
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* call.)
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*/
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#define CPU_CLOCKUPDATE(otime, ntime) \
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do { \
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if (i586_ctr_freq != 0) { \
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disable_intr(); \
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i586_ctr_bias = i586_last_tick; \
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*(otime) = *(ntime); \
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enable_intr(); \
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} else { \
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*(otime) = *(ntime); \
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} \
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} while(0)
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#define CPU_THISTICKLEN(dflt) cpu_thisticklen(dflt)
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#define CPU_CLOCKUPDATE(otime, ntime) cpu_clockupdate((otime), (ntime))
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#else
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#define CPU_CLOCKUPDATE(otime, ntime) \
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(*(otime) = *(ntime))
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#define CPU_THISTICKLEN(dflt) dflt
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#define CPU_CLOCKUPDATE(otime, ntime) (*(otime) = *(ntime))
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#endif
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#define CPU_THISTICKLEN(dflt) dflt
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#define I586_CTR_COMULTIPLIER_SHIFT 20
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#define I586_CTR_MULTIPLIER_SHIFT 32
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#if defined(KERNEL) && !defined(LOCORE)
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#include <sys/cdefs.h>
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#include <machine/frame.h>
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#ifdef KERNEL
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/*
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* i386 to clock driver interface.
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* XXX almost all of it is misplaced. i586 stuff is done in isa/clock.c
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@ -57,8 +33,6 @@ extern u_int i586_ctr_bias;
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extern u_int i586_ctr_comultiplier;
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extern u_int i586_ctr_freq;
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extern u_int i586_ctr_multiplier;
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extern long long i586_last_tick;
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extern unsigned long i586_avg_tick;
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#endif
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extern int statclock_disable;
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extern u_int timer_freq;
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@ -67,27 +41,11 @@ extern u_int timer0_overflow_threshold;
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extern u_int timer0_prescaler_count;
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extern int wall_cmos_clock;
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#if defined(I586_CPU) || defined(I686_CPU)
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static __inline u_long
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cpu_thisticklen(u_long dflt)
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{
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long long old;
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long len;
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if (i586_ctr_freq != 0) {
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old = i586_last_tick;
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i586_last_tick = rdtsc();
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len = ((i586_last_tick - old) * i586_ctr_multiplier)
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>> I586_CTR_MULTIPLIER_SHIFT;
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i586_avg_tick = i586_avg_tick * 15 / 16 + len / 16;
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}
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return dflt;
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}
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#endif
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/*
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* Driver to clock driver interface.
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*/
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struct clockframe;
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void DELAY __P((int usec));
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int acquire_timer0 __P((int rate,
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void (*function)(struct clockframe *frame)));
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@ -105,6 +63,59 @@ void rtc_outb __P((int val));
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#endif
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int sysbeep __P((int pitch, int period));
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#endif /* KERNEL && !LOCORE */
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#ifdef CLOCK_HAIR
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#include <i386/isa/isa.h> /* XXX */
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#include <i386/isa/timerreg.h> /* XXX */
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static __inline u_int
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clock_latency(void)
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{
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u_char high, low;
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outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
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low = inb(TIMER_CNTR0);
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high = inb(TIMER_CNTR0);
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return (timer0_prescaler_count + timer0_max_count
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- ((high << 8) | low));
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}
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#if defined(I586_CPU) || defined(I686_CPU)
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/*
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* When we update `time', on i586's we also update `i586_ctr_bias'
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* atomically. `i586_ctr_bias' is the best available approximation to
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* the value of the i586 counter (mod 2^32) at the time of the i8254
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* counter transition that caused the clock interrupt that caused the
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* update. clock_latency() gives the time between the transition and
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* the update to within a few usec provided another such transition
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* hasn't occurred. We don't bother checking for counter overflow as
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* in microtime(), since if it occurs then we're close to losing clock
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* interrupts.
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*/
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static __inline void
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cpu_clockupdate(volatile struct timeval *otime, struct timeval *ntime)
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{
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if (i586_ctr_freq != 0) {
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u_int i586_count; /* truncated */
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u_int i8254_count;
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disable_intr();
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i8254_count = clock_latency();
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i586_count = rdtsc();
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i586_ctr_bias = i586_count
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- (u_int)
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(((unsigned long long)i586_ctr_comultiplier
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* i8254_count)
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>> I586_CTR_COMULTIPLIER_SHIFT);
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*otime = *ntime;
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enable_intr();
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} else
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*otime = *ntime;
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}
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#endif /* I586_CPU || I686_CPU */
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#endif /* CLOCK_HAIR */
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#endif /* KERNEL */
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#endif /* !_MACHINE_CLOCK_H_ */
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@ -3,48 +3,24 @@
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* Garrett Wollman, September 1994.
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* This file is in the public domain.
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*
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* $Id: clock.h,v 1.18 1996/10/10 10:25:26 bde Exp $
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* $Id: clock.h,v 1.19 1996/10/17 17:31:25 bde Exp $
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*/
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#ifndef _MACHINE_CLOCK_H_
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#define _MACHINE_CLOCK_H_
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#if defined(I586_CPU) || defined(I686_CPU)
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/*
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* When we update the clock, we also update this bias value which is
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* automatically subtracted in microtime(). We assume that CPU_THISTICKLEN()
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* has been called at some point in the past, so that an appropriate value is
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* set up in i586_last_tick. (This works even if we are not being called
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* from hardclock because hardclock will have run before and will made the
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* call.)
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*/
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#define CPU_CLOCKUPDATE(otime, ntime) \
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do { \
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if (i586_ctr_freq != 0) { \
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disable_intr(); \
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i586_ctr_bias = i586_last_tick; \
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*(otime) = *(ntime); \
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enable_intr(); \
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} else { \
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*(otime) = *(ntime); \
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} \
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} while(0)
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#define CPU_THISTICKLEN(dflt) cpu_thisticklen(dflt)
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#define CPU_CLOCKUPDATE(otime, ntime) cpu_clockupdate((otime), (ntime))
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#else
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#define CPU_CLOCKUPDATE(otime, ntime) \
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(*(otime) = *(ntime))
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#define CPU_THISTICKLEN(dflt) dflt
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#define CPU_CLOCKUPDATE(otime, ntime) (*(otime) = *(ntime))
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#endif
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#define CPU_THISTICKLEN(dflt) dflt
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#define I586_CTR_COMULTIPLIER_SHIFT 20
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#define I586_CTR_MULTIPLIER_SHIFT 32
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#if defined(KERNEL) && !defined(LOCORE)
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#include <sys/cdefs.h>
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#include <machine/frame.h>
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#ifdef KERNEL
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/*
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* i386 to clock driver interface.
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* XXX almost all of it is misplaced. i586 stuff is done in isa/clock.c
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@ -57,8 +33,6 @@ extern u_int i586_ctr_bias;
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extern u_int i586_ctr_comultiplier;
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extern u_int i586_ctr_freq;
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extern u_int i586_ctr_multiplier;
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extern long long i586_last_tick;
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extern unsigned long i586_avg_tick;
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#endif
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extern int statclock_disable;
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extern u_int timer_freq;
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@ -67,27 +41,11 @@ extern u_int timer0_overflow_threshold;
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extern u_int timer0_prescaler_count;
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extern int wall_cmos_clock;
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#if defined(I586_CPU) || defined(I686_CPU)
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static __inline u_long
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cpu_thisticklen(u_long dflt)
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{
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long long old;
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long len;
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if (i586_ctr_freq != 0) {
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old = i586_last_tick;
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i586_last_tick = rdtsc();
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len = ((i586_last_tick - old) * i586_ctr_multiplier)
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>> I586_CTR_MULTIPLIER_SHIFT;
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i586_avg_tick = i586_avg_tick * 15 / 16 + len / 16;
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}
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return dflt;
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}
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#endif
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/*
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* Driver to clock driver interface.
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*/
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struct clockframe;
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void DELAY __P((int usec));
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int acquire_timer0 __P((int rate,
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void (*function)(struct clockframe *frame)));
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@ -105,6 +63,59 @@ void rtc_outb __P((int val));
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#endif
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int sysbeep __P((int pitch, int period));
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#endif /* KERNEL && !LOCORE */
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#ifdef CLOCK_HAIR
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#include <i386/isa/isa.h> /* XXX */
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#include <i386/isa/timerreg.h> /* XXX */
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static __inline u_int
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clock_latency(void)
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{
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u_char high, low;
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outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
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low = inb(TIMER_CNTR0);
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high = inb(TIMER_CNTR0);
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return (timer0_prescaler_count + timer0_max_count
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- ((high << 8) | low));
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}
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#if defined(I586_CPU) || defined(I686_CPU)
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/*
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* When we update `time', on i586's we also update `i586_ctr_bias'
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* atomically. `i586_ctr_bias' is the best available approximation to
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* the value of the i586 counter (mod 2^32) at the time of the i8254
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* counter transition that caused the clock interrupt that caused the
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* update. clock_latency() gives the time between the transition and
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* the update to within a few usec provided another such transition
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* hasn't occurred. We don't bother checking for counter overflow as
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* in microtime(), since if it occurs then we're close to losing clock
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* interrupts.
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*/
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static __inline void
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cpu_clockupdate(volatile struct timeval *otime, struct timeval *ntime)
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{
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if (i586_ctr_freq != 0) {
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u_int i586_count; /* truncated */
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u_int i8254_count;
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disable_intr();
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i8254_count = clock_latency();
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i586_count = rdtsc();
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i586_ctr_bias = i586_count
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- (u_int)
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(((unsigned long long)i586_ctr_comultiplier
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* i8254_count)
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>> I586_CTR_COMULTIPLIER_SHIFT);
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*otime = *ntime;
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enable_intr();
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} else
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*otime = *ntime;
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}
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#endif /* I586_CPU || I686_CPU */
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#endif /* CLOCK_HAIR */
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#endif /* KERNEL */
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#endif /* !_MACHINE_CLOCK_H_ */
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@ -36,7 +36,7 @@
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* SUCH DAMAGE.
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*
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* @(#)kern_clock.c 8.5 (Berkeley) 1/21/94
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* $Id: kern_clock.c,v 1.26 1996/07/30 16:59:22 bde Exp $
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* $Id: kern_clock.c,v 1.27 1996/10/10 10:25:03 bde Exp $
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*/
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/* Portions of this software are covered by the following: */
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@ -76,6 +76,7 @@
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#include <sys/sysctl.h>
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#include <machine/cpu.h>
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#define CLOCK_HAIR /* XXX */
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#include <machine/clock.h>
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#ifdef GPROF
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@ -36,7 +36,7 @@
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* SUCH DAMAGE.
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*
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* @(#)kern_clock.c 8.5 (Berkeley) 1/21/94
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* $Id: kern_clock.c,v 1.26 1996/07/30 16:59:22 bde Exp $
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* $Id: kern_clock.c,v 1.27 1996/10/10 10:25:03 bde Exp $
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*/
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/* Portions of this software are covered by the following: */
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@ -76,6 +76,7 @@
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#include <sys/sysctl.h>
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#include <machine/cpu.h>
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#define CLOCK_HAIR /* XXX */
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#include <machine/clock.h>
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#ifdef GPROF
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@ -36,7 +36,7 @@
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* SUCH DAMAGE.
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*
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* @(#)kern_clock.c 8.5 (Berkeley) 1/21/94
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* $Id: kern_clock.c,v 1.26 1996/07/30 16:59:22 bde Exp $
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* $Id: kern_clock.c,v 1.27 1996/10/10 10:25:03 bde Exp $
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*/
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/* Portions of this software are covered by the following: */
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@ -76,6 +76,7 @@
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#include <sys/sysctl.h>
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#include <machine/cpu.h>
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#define CLOCK_HAIR /* XXX */
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#include <machine/clock.h>
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#ifdef GPROF
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