machdep.c

早期freebsd实现

			nbusy = 0;
			for (bp = &buf[nbuf]; --bp >= buf; )
				if ((bp->b_flags & (B_BUSY|B_INVAL)) == B_BUSY)
					nbusy++;
			if (nbusy == 0)
				break;
			printf("%d ", nbusy);
			DELAY(40000 * iter);
		}
		if (nbusy)
			printf("giving up\n");
		else
			printf("done\n");
		/*
		 * If we've been adjusting the clock, the todr
		 * will be out of synch; adjust it now.
		 */
		resettodr();
	}
	splhigh();			/* extreme priority */
	if (howto&RB_HALT) {
		printf("halted\n\n");
		asm("	stop	#0x2700");
	} else {
		if (howto & RB_DUMP)
			dumpsys();
		doboot();
		/*NOTREACHED*/
	}
	/*NOTREACHED*/
}

int	dumpmag = 0x8fca0101;	/* magic number for savecore */
int	dumpsize = 0;		/* also for savecore */
long	dumplo = 0;

dumpconf()
{
	int nblks;

	/*
	 * XXX include the final RAM page which is not included in physmem.
	 */
	dumpsize = physmem + 1;
	if (dumpdev != NODEV && bdevsw[major(dumpdev)].d_psize) {
		nblks = (*bdevsw[major(dumpdev)].d_psize)(dumpdev);
		if (dumpsize > btoc(dbtob(nblks - dumplo)))
			dumpsize = btoc(dbtob(nblks - dumplo));
		else if (dumplo == 0)
			dumplo = nblks - btodb(ctob(dumpsize));
	}
	/*
	 * Don't dump on the first CLBYTES (why CLBYTES?)
	 * in case the dump device includes a disk label.
	 */
	if (dumplo < btodb(CLBYTES))
		dumplo = btodb(CLBYTES);
}

/*
 * Doadump comes here after turning off memory management and
 * getting on the dump stack, either when called above, or by
 * the auto-restart code.
 */
dumpsys()
{

	msgbufmapped = 0;
	if (dumpdev == NODEV)
		return;
	/*
	 * For dumps during autoconfiguration,
	 * if dump device has already configured...
	 */
	if (dumpsize == 0)
		dumpconf();
	if (dumplo < 0)
		return;
	printf("\ndumping to dev %x, offset %d\n", dumpdev, dumplo);
	printf("dump ");
	switch ((*bdevsw[major(dumpdev)].d_dump)(dumpdev)) {

	case ENXIO:
		printf("device bad\n");
		break;

	case EFAULT:
		printf("device not ready\n");
		break;

	case EINVAL:
		printf("area improper\n");
		break;

	case EIO:
		printf("i/o error\n");
		break;

	default:
		printf("succeeded\n");
		break;
	}
}

initcpu()
{
#ifdef MAPPEDCOPY
	extern u_int mappedcopysize;

	/*
	 * Initialize lower bound for doing copyin/copyout using
	 * page mapping (if not already set).  We don't do this on
	 * VAC machines as it loses big time.
	 */
	if (mappedcopysize == 0) {
		if (ectype == EC_VIRT)
			mappedcopysize = (u_int) -1;
		else
			mappedcopysize = NBPG;
	}
#endif
	parityenable();
#ifdef USELEDS
	ledinit();
#endif
}

straytrap(pc, evec)
	int pc;
	u_short evec;
{
	printf("unexpected trap (vector offset %x) from %x\n",
	       evec & 0xFFF, pc);
}

int	*nofault;

badaddr(addr)
	register caddr_t addr;
{
	register int i;
	label_t	faultbuf;

#ifdef lint
	i = *addr; if (i) return(0);
#endif
	nofault = (int *) &faultbuf;
	if (setjmp((label_t *)nofault)) {
		nofault = (int *) 0;
		return(1);
	}
	i = *(volatile short *)addr;
	nofault = (int *) 0;
	return(0);
}

badbaddr(addr)
	register caddr_t addr;
{
	register int i;
	label_t	faultbuf;

#ifdef lint
	i = *addr; if (i) return(0);
#endif
	nofault = (int *) &faultbuf;
	if (setjmp((label_t *)nofault)) {
		nofault = (int *) 0;
		return(1);
	}
	i = *(volatile char *)addr;
	nofault = (int *) 0;
	return(0);
}

netintr()
{
#ifdef INET
	if (netisr & (1 << NETISR_ARP)) {
		netisr &= ~(1 << NETISR_ARP);
		arpintr();
	}
	if (netisr & (1 << NETISR_IP)) {
		netisr &= ~(1 << NETISR_IP);
		ipintr();
	}
#endif
#ifdef NS
	if (netisr & (1 << NETISR_NS)) {
		netisr &= ~(1 << NETISR_NS);
		nsintr();
	}
#endif
#ifdef ISO
	if (netisr & (1 << NETISR_ISO)) {
		netisr &= ~(1 << NETISR_ISO);
		clnlintr();
	}
#endif
#ifdef CCITT
	if (netisr & (1 << NETISR_CCITT)) {
		netisr &= ~(1 << NETISR_CCITT);
		ccittintr();
	}
#endif
}

intrhand(sr)
	int sr;
{
	register struct isr *isr;
	register int found = 0;
	register int ipl;
	extern struct isr isrqueue[];
	static int straycount;

	ipl = (sr >> 8) & 7;
	switch (ipl) {

	case 3:
	case 4:
	case 5:
		ipl = ISRIPL(ipl);
		isr = isrqueue[ipl].isr_forw;
		for (; isr != &isrqueue[ipl]; isr = isr->isr_forw) {
			if ((isr->isr_intr)(isr->isr_arg)) {
				found++;
				break;
			}
		}
		if (found)
			straycount = 0;
		else if (++straycount > 50)
			panic("intrhand: stray interrupt");
		else
			printf("stray interrupt, sr 0x%x\n", sr);
		break;

	case 0:
	case 1:
	case 2:
	case 6:
	case 7:
		if (++straycount > 50)
			panic("intrhand: unexpected sr");
		else
			printf("intrhand: unexpected sr 0x%x\n", sr);
		break;
	}
}

#if defined(DEBUG) && !defined(PANICBUTTON)
#define PANICBUTTON
#endif

#ifdef PANICBUTTON
int panicbutton = 1;	/* non-zero if panic buttons are enabled */
int crashandburn = 0;
int candbdelay = 50;	/* give em half a second */

void
candbtimer(arg)
	void *arg;
{

	crashandburn = 0;
}
#endif

/*
 * Level 7 interrupts can be caused by the keyboard or parity errors.
 */
nmihand(frame)
	struct frame frame;
{
	if (kbdnmi()) {
#ifdef PANICBUTTON
		static int innmihand = 0;

		/*
		 * Attempt to reduce the window of vulnerability for recursive
		 * NMIs (e.g. someone holding down the keyboard reset button).
		 */
		if (innmihand == 0) {
			innmihand = 1;
			printf("Got a keyboard NMI\n");
			innmihand = 0;
		}
		if (panicbutton) {
			if (crashandburn) {
				crashandburn = 0;
				panic(panicstr ?
				      "forced crash, nosync" : "forced crash");
			}
			crashandburn++;
			timeout(candbtimer, (void *)0, candbdelay);
		}
#endif
		return;
	}
	if (parityerror(&frame))
		return;
	/* panic?? */
	printf("unexpected level 7 interrupt ignored\n");
}

/*
 * Parity error section.  Contains magic.
 */
#define PARREG		((volatile short *)IIOV(0x5B0000))
static int gotparmem = 0;
#ifdef DEBUG
int ignorekperr = 0;	/* ignore kernel parity errors */
#endif

/*
 * Enable parity detection
 */
parityenable()
{
	label_t	faultbuf;

	nofault = (int *) &faultbuf;
	if (setjmp((label_t *)nofault)) {
		nofault = (int *) 0;
#ifdef DEBUG
		printf("No parity memory\n");
#endif
		return;
	}
	*PARREG = 1;
	nofault = (int *) 0;
	gotparmem = 1;
#ifdef DEBUG
	printf("Parity detection enabled\n");
#endif
}

/*
 * Determine if level 7 interrupt was caused by a parity error
 * and deal with it if it was.  Returns 1 if it was a parity error.
 */
parityerror(fp)
	struct frame *fp;
{
	if (!gotparmem)
		return(0);
	*PARREG = 0;
	DELAY(10);
	*PARREG = 1;
	if (panicstr) {
		printf("parity error after panic ignored\n");
		return(1);
	}
	if (!findparerror())
		printf("WARNING: transient parity error ignored\n");
	else if (USERMODE(fp->f_sr)) {
		printf("pid %d: parity error\n", curproc->p_pid);
		uprintf("sorry, pid %d killed due to memory parity error\n",
			curproc->p_pid);
		psignal(curproc, SIGKILL);
#ifdef DEBUG
	} else if (ignorekperr) {
		printf("WARNING: kernel parity error ignored\n");
#endif
	} else {
		regdump(fp, 128);
		panic("kernel parity error");
	}
	return(1);
}

/*
 * Yuk!  There has got to be a better way to do this!
 * Searching all of memory with interrupts blocked can lead to disaster.
 */
findparerror()
{
	static label_t parcatch;
	static int looking = 0;
	volatile int pg, o, s;
	register volatile int *ip;
	register int i;
	int found;

#ifdef lint
	i = o = pg = 0; if (i) return(0);
#endif
	/*
	 * If looking is true we are searching for a known parity error
	 * and it has just occured.  All we do is return to the higher
	 * level invocation.
	 */
	if (looking)
		longjmp(&parcatch);
	s = splhigh();
	/*
	 * If setjmp returns true, the parity error we were searching
	 * for has just occured (longjmp above) at the current pg+o
	 */
	if (setjmp(&parcatch)) {
		printf("Parity error at 0x%x\n", ctob(pg)|o);
		found = 1;
		goto done;
	}
	/*
	 * If we get here, a parity error has occured for the first time
	 * and we need to find it.  We turn off any external caches and
	 * loop thru memory, testing every longword til a fault occurs and
	 * we regain control at setjmp above.  Note that because of the
	 * setjmp, pg and o need to be volatile or their values will be lost.
	 */
	looking = 1;
	ecacheoff();
	for (pg = btoc(lowram); pg < btoc(lowram)+physmem; pg++) {
		pmap_enter(kernel_pmap, (vm_offset_t)vmmap, ctob(pg),
		    VM_PROT_READ, TRUE);
		ip = (int *)vmmap;
		for (o = 0; o < NBPG; o += sizeof(int))
			i = *ip++;
	}
	/*
	 * Getting here implies no fault was found.  Should never happen.
	 */
	printf("Couldn't locate parity error\n");
	found = 0;
done:
	looking = 0;
	pmap_remove(kernel_pmap, (vm_offset_t)vmmap, (vm_offset_t)&vmmap[NBPG]);
	ecacheon();
	splx(s);
	return(found);
}

regdump(fp, sbytes)
	struct frame *fp; /* must not be register */
	int sbytes;
{
	static int doingdump = 0;
	register int i;
	int s;
	extern char *hexstr();

	if (doingdump)
		return;
	s = splhigh();
	doingdump = 1;
	printf("pid = %d, pc = %s, ",
	       curproc ? curproc->p_pid : -1, hexstr(fp->f_pc, 8));
	printf("ps = %s, ", hexstr(fp->f_sr, 4));
	printf("sfc = %s, ", hexstr(getsfc(), 4));
	printf("dfc = %s\n", hexstr(getdfc(), 4));
	printf("Registers:\n     ");
	for (i = 0; i < 8; i++)
		printf("        %d", i);
	printf("\ndreg:");
	for (i = 0; i < 8; i++)
		printf(" %s", hexstr(fp->f_regs[i], 8));
	printf("\nareg:");
	for (i = 0; i < 8; i++)
		printf(" %s", hexstr(fp->f_regs[i+8], 8));
	if (sbytes > 0) {
		if (fp->f_sr & PSL_S) {
			printf("\n\nKernel stack (%s):",
			       hexstr((int)(((int *)&fp)-1), 8));
			dumpmem(((int *)&fp)-1, sbytes, 0);
		} else {
			printf("\n\nUser stack (%s):", hexstr(fp->f_regs[SP], 8));
			dumpmem((int *)fp->f_regs[SP], sbytes, 1);
		}
	}
	doingdump = 0;
	splx(s);
}

extern char kstack[];
#define KSADDR	((int *)&(kstack[(UPAGES-1)*NBPG]))

dumpmem(ptr, sz, ustack)
	register int *ptr;
	int sz, ustack;
{
	register int i, val;
	extern char *hexstr();

	for (i = 0; i < sz; i++) {
		if ((i & 7) == 0)
			printf("\n%s: ", hexstr((int)ptr, 6));
		else
			printf(" ");
		if (ustack == 1) {
			if ((val = fuword(ptr++)) == -1)
				break;
		} else {
			if (ustack == 0 &&
			    (ptr < KSADDR || ptr > KSADDR+(NBPG/4-1)))
				break;
			val = *ptr++;
		}
		printf("%s", hexstr(val, 8));
	}
	printf("\n");
}

char *
hexstr(val, len)
	register int val;
	int len;
{
	static char nbuf[9];
	register int x, i;

	if (len > 8)
		return("");
	nbuf[len] = '\0';
	for (i = len-1; i >= 0; --i) {
		x = val & 0xF;
		if (x > 9)
			nbuf[i] = x - 10 + 'A';
		else
			nbuf[i] = x + '0';
		val >>= 4;
	}
	return(nbuf);
}

#ifdef DEBUG
char oflowmsg[] = "k-stack overflow";
char uflowmsg[] = "k-stack underflow";

badkstack(oflow, fr)
	int oflow;
	struct frame fr;
{
	extern char kstackatbase[];

	printf("%s: sp should be %x\n", 
	       oflow ? oflowmsg : uflowmsg,
	       kstackatbase - (exframesize[fr.f_format] + 8));
	regdump(&fr, 0);
	panic(oflow ? oflowmsg : uflowmsg);
}
#endif