ref: 2cab6c0b2f7ccfad3c7990070ab0917cfd978cf1
dir: /os/rpcg/clock.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" #include "ureg.h" #include <isa.h> #include <interp.h> typedef struct Clock0link Clock0link; typedef struct Clock0link { void (*clock)(void); Clock0link* link; } Clock0link; static Clock0link *clock0link; static Lock clock0lock; ulong clkrelinq; void (*kproftick)(ulong); /* set by devkprof.c when active */ void (*archclocktick)(void); /* set by arch*.c when desired */ Timer* addclock0link(void (*clock)(void), int) { Clock0link *lp; if((lp = malloc(sizeof(Clock0link))) == 0){ print("addclock0link: too many links\n"); return nil; } ilock(&clock0lock); lp->clock = clock; lp->link = clock0link; clock0link = lp; iunlock(&clock0lock); return nil; } void delay(int l) { ulong i, j; j = m->delayloop; while(l-- > 0) for(i=0; i < j; i++) ; } void microdelay(int l) { ulong i; l *= m->delayloop; l /= 1000; if(l <= 0) l = 1; for(i = 0; i < l; i++) ; } enum { Timebase = 2, /* system clock cycles per time base cycle */ }; static ulong clkreload; void clockinit(void) { long x; m->delayloop = m->cpuhz/1000; /* initial estimate */ do { x = gettbl(); delay(10); x = gettbl() - x; } while(x < 0); /* * fix count */ m->delayloop = ((vlong)m->delayloop*(10*m->clockgen/1000))/(x*Timebase); if(m->delayloop == 0) m->delayloop = 1; clkreload = (m->clockgen/Timebase)/HZ-1; putdec(clkreload); } void clockintr(Ureg *ur) { Clock0link *lp; long v; v = -getdec(); if(v > clkreload/2){ if(v > clkreload) m->ticks += v/clkreload; v = 0; } putdec(clkreload-v); /* watchdog */ if(m->iomem->sypcr & (1<<2)){ m->iomem->swsr = 0x556c; m->iomem->swsr = 0xaa39; } m->ticks++; if(archclocktick != nil) archclocktick(); if(up) up->pc = ur->pc; checkalarms(); if(m->machno == 0) { if(kproftick != nil) (*kproftick)(ur->pc); if(canlock(&clock0lock)){ for(lp = clock0link; lp; lp = lp->link) lp->clock(); unlock(&clock0lock); } } if(up && up->state == Running){ if(cflag && up->type == Interp && tready(nil)) ur->cr |= 1; /* set flag in condition register for ../../libinterp/comp-power.c:/^schedcheck */ } /* other preemption checks are done by trap.c */ } uvlong fastticks(uvlong *hz) { if(hz) *hz = HZ; return m->ticks; }