devastar.c

著名操作系统Plan 9的第三版的部分核心源代码。现在很难找到了。Plan 9是bell实验室开发的Unix后继者。

		if(ioalloc(a->port, 6, 0, name) < 0){
			print("#G%d: port 0x%lux in use\n", a->id, a->port);
			return -1;
		}
		found = astarprobe(a->port);
	}
	if(!found){
		print("#G%d: not found\n", a->id);
		iofree(a->port);
		return -1;
	}

	/* check interrupt level */
	if(isairqcode[a->irq] == -1){
		print("#G%d: bad irq %lud\n", a->id, a->irq);
		iofree(a->port);
		return -1;
	}

	/* set ISA memory address */
	outb(a->port+ISAmaddr, (a->mem>>12) & 0xfc);
	a->gcb = KADDR(a->mem);
	a->addr = KADDR(a->mem);

	/* disable ISA memory response */
	outb(a->port+ISActl2, 0);
	a->memsize = 0;
	a->page = -1;

	/* reset processor */
	outb(a->port+ISActl1, 0);

	return 0;
}

static Chan*
astarattach(char *spec)
{
	ulong ctlrno;
	char *p;

	ctlrno = 0;
	if(spec && *spec){
		ctlrno = strtoul(spec, &p, 0);
		if((ctlrno == 0 && p == spec) || *p || (ctlrno >= Maxcard))
			error(Ebadarg);
	}
	if(astar[ctlrno] == nil)
		error(Enodev);

	return devattach('G', spec);
}

static int
astarwalk(Chan *c, char *name)
{
	return devwalk(c, name, 0, 0, astargen);
}

static void
astarstat(Chan *c, char *dp)
{
	devstat(c, dp, 0, 0, astargen);
}

static Chan*
astaropen(Chan *c, int omode)
{
	Astar *a;
	Astarchan *ac;

	c = devopen(c, omode, 0, 0, astargen);
	a = astar[BOARD(c->qid.path)];

	switch(TYPE(c->qid.path)){
	case Qmem:
	case Qbctl:
		if(!iseve())
			error(Eperm);
		break;
	case Qdata:
	case Qctl:
		ac = a->c + CHAN(c->qid.path);
		qlock(ac);
		if(waserror()){
			qunlock(ac);
			ac->opens--;
			nexterror();
		}
		if(ac->opens++ == 0){
			enable(ac);
			qreopen(ac->iq);
			qreopen(ac->oq);
		}
		qunlock(ac);
		poperror();
		break;
	}

	return c;
}

static void
astarclose(Chan *c)
{
	Astar *a;
	Astarchan *ac;

	if((c->flag & COPEN) == 0)
		return;

	a = astar[BOARD(c->qid.path)];

	switch(TYPE(c->qid.path)){
	case Qdata:
	case Qctl:
		ac = a->c + CHAN(c->qid.path);
		qlock(ac);
		if(waserror()){
			qunlock(ac);
			nexterror();
		}
		if(--(ac->opens) == 0){
			disable(ac);
			qclose(ac->iq);
			qclose(ac->oq);
		}
		qunlock(ac);
		poperror();
		break;
	}
}

/*
 *  read PCI mapped memory
 */
static long
pcimemread(Astar *a, uchar *to, long n, ulong offset)
{
	uchar *from;
	int rem;

	if(offset+n > a->memsize){
		if(offset >= a->memsize)
			return 0;
		n = a->memsize - offset;
	}

	from = a->addr+offset;
	for(rem = n; rem > 0; rem--)
		*to++ = *from++;

	return n;
}

/*
 *  read ISA mapped memory
 */
static long
isamemread(Astar *a, uchar *to, long n, ulong offset)
{
	uchar *from, *e, *tp;
	int i, rem;
	uchar tmp[256];

	if(offset+n > a->memsize){
		if(offset >= a->memsize)
			return 0;
		n = a->memsize - offset;
	}

	for(rem = n; rem > 0; rem -= i){

		/* map in right piece of memory */
		i = offset&Pagemask;
		from = a->addr + i;
		i = Pagesize - i;
		if(i > rem)
			i = rem;
		if(i > sizeof(tmp))
			i = sizeof(tmp);

		/*
		 *  byte at a time so endian doesn't matter,
		 *  go via tmp to avoid pagefaults while ilock'd
		 */
		tp = tmp;
		LOCKPAGE(a, offset);
		for(e = tp + i; tp < e;)
			*tp++ = *from++;
		UNLOCKPAGE(a);
		memmove(to, tmp, i);
		to += i;

		offset += i;
	}

	return n;
}

/*
 *  read ISA status
 */
static long
bctlread(Astar *a, void *buf, long n, ulong offset)
{
	char s[128];

	if(a->pci)
		sprint(s, "range %luX remap %luX region %luX mailbox %luX doorbell0 %luX doorbell1 %luX control %luX command %luX",
			inl(a->port+PCIrange),
			inl(a->port+PCIremap),
			inl(a->port+PCIregion),
			inl(a->port+PCImailbox),
			inl(a->port+PCIdoorbell0),
			inl(a->port+PCIdoorbell1),
			inl(a->port+PCIcontrol),
			inl(a->port+PCIcommand));
	else
		sprint(s, "id %4.4ux ctl1 %2.2ux ctl2 %2.2ux maddr %2.2ux stat %4.4ux",
			(inb(a->port+ISAid)<<8)|inb(a->port+ISAid),
			inb(a->port+ISActl1), inb(a->port+ISActl2), 
			inb(a->port+ISAmaddr),
			(inb(a->port+ISAstat2)<<8)|inb(a->port+ISAstat1));

	return readstr(offset, buf, n, s);
}

static long
statread(Astarchan *ac, void *buf, long n, ulong offset)
{
	char s[256];
	int mstat, bstat, fstat;

	LOCKPAGE(ac->a, 0);
	mstat = LEUS(ac->ccb->mstat);
	bstat = LEUS(ac->ccb->bstat);
	fstat = LEUS(ac->ccb->format);
	UNLOCKPAGE(ac->a);

	snprint(s, sizeof s,
		"b%d c%d d%d e%d l%d m%d p%c r%d s%d\n"
		"%ld %d %d%s%s%s%s\n",

		ac->baud,
		ac->hup_dcd,
		ac->dtr,
		ac->hup_dsr,
		(fstat & Clenmask),
		0, 	/* change in modem status? */
		(fstat & Cparmask) ? ((fstat & Cevenpar) == Cevenpar ? 'e' : 'o') : 'n',
		(bstat & Crbrts) ? 1 : 0,
		(fstat & C2stop) ? 2 : 1,

		ac - ac->a->c,
		ac->framing,
		ac->overrun,
		(mstat & Cctsstat)    ? " cts"  : "",
		(mstat & Cdsrstat)    ? " dsr"  : "",
		(mstat & Cdcdstat)    ? " dcd"  : "",
		(mstat & Cristat)   ? " ring" : ""
	);
	return readstr(offset, buf, n, s);
}

static long
astarread(Chan *c, void *buf, long n, vlong off)
{
	Astar *a;
	Astarchan *ac;
	ulong offset = off;

	if(c->qid.path & CHDIR)
		return devdirread(c, buf, n, 0, 0, astargen);

	switch(TYPE(c->qid.path)){
	case Qstat:
		a = astar[BOARD(c->qid.path)];
		return statread(a->c + CHAN(c->qid.path), buf, n, offset);
	case Qmem:
		a = astar[BOARD(c->qid.path)];
		if(a->pci)
			return pcimemread(a, buf, n, offset);
		return isamemread(a, buf, n, offset);
	case Qbctl:
		return bctlread(astar[BOARD(c->qid.path)], buf, n, offset);
	case Qdata:
		a = astar[BOARD(c->qid.path)];
		ac = a->c + CHAN(c->qid.path);
		return qread(ac->iq, buf, n);
	}

	return 0;
}

/*
 *  write PCI mapped memory
 */
static long
pcimemwrite(Astar *a, uchar *from, long n, ulong offset)
{
	uchar *to;
	int rem;
	ulong limit;

	/*
	 * Disallow writes above 0xD000 where the i960
	 * data structures live if writing in the lower bank.
	 */
	if(a->addr == (uchar*)a->mem)
		limit = 0xD000;
	else
		limit = a->memsize;
	if(offset+n > limit){
		if(offset >= limit)
			return 0;
		n = limit - offset;
	}

	to = a->addr+offset;
	for(rem = n; rem > 0; rem--)
		*to++ = *from++;

	return n;
}

/*
 *  write ISA mapped memory
 */
static long
isamemwrite(Astar *a, uchar *from, long n, ulong offset)
{
	uchar *to, *e, *tp;
	int i, rem;
	uchar tmp[256];

	if(offset+n > a->memsize){
		if(offset >= a->memsize)
			return 0;
		n = a->memsize - offset;
	}

	for(rem = n; rem > 0; rem -= i){

		/* map in right piece of memory */
		i = offset&Pagemask;
		to = a->addr + i;
		i = Pagesize - i;
		if(i > rem)
			i = rem;
		if(i > sizeof(tmp))
			i = sizeof(tmp);
		
		/*
		 *  byte at a time so endian doesn't matter,
		 *  go via tmp to avoid pagefaults while ilock'd
		 */
		memmove(tmp, from, i);
		tp = tmp;
		LOCKPAGE(a, offset);
		for(e = tp + i; tp < e;)
			*to++ = *tp++;
		UNLOCKPAGE(a);
		from += i;

		offset += i;
	}

	return n;
}

/*
 *  put board into download mode
 */
static void
downloadmode(Astar *a)
{
	int c, i;

	/* put board in download mode */
	if(a->pci){
		/*
		 * Don't let the download write over the
		 * i960 data structures.
		 */
		a->memsize = 0xD000;
		a->addr = (uchar*)a->mem;
	}
	else{
		a->memsize = Pramsize;
		a->needpage = 1;
		c = inb(a->port+ISActl1);
		outb(a->port+ISActl1, c & ~ISAnotdl);

		/* give it up to 5 seconds to reset */
		for(i = 0; i < 21; i++){
			if(!(inb(a->port+ISActl1) & ISAnotdl))
				break;
			tsleep(&a->r, return0, 0, 500);
		}
		if(inb(a->port+ISActl1) & ISAnotdl){
			print("#G%d: did not reset\n", a->id);
			error(Eio);
		}

		/* enable ISA access to first 16k */
		a->page = -1;
		setpage(a, 0);
	}
}

/*
 *  start control program
 */
static void
startcp(Astar *a)
{
	int c, n, i, sz;
	uchar *x;
	CCB *ccb;
	Astarchan *ac;
	char name[10];

	if(a->running)
		error(Eio);

	/* take board out of download mode and enable IRQ */
	if(a->pci){
		outl(a->port+PCImailbox, 1);

		/* wait for control program to signal life */
		delay(100);
		for(i = 0; i < 10; i++){
			if(inl(a->port+PCImailbox) & 0x80000000)
				break;
			tsleep(&a->r, return0, 0, 100);
		}
		if(!(inl(a->port+PCImailbox) & 0x80000000)){
			print("#G%d: program not ready\n", a->id);
			//error(Eio);
		}

		a->addr = (uchar*)(a->mem+0x10000);
	}
	else{
		c = inb(a->port+ISActl1);
		outb(a->port+ISActl1, c|ISAien|ISAnotdl);

		/* wait for control program to signal life */
		for(i = 0; i < 21; i++){
			if(inb(a->port+ISActl1) & ISApr)
				break;
			tsleep(&a->r, return0, 0, 500);
		}
		if((inb(a->port+ISActl1) & ISApr) == 0){
			print("#G%d: program not ready\n", a->id);
			error(Eio);
		}
	}

	a->memsize = a->ramsize;
	if(a->pci || a->memsize <= Pagesize)
		a->needpage = 0;
	else{
		a->page = -1;
		setpage(a, 0);
		a->needpage = 1;
	}

	if(waserror()){
		UNLOCKPAGE(a);
		poperror();
	}

	LOCKPAGE(a, 0);
	i = LEUS(a->gcb->type);
	switch(i){
	default:
		print("#G%d: wrong board type %uX\n", a->id, i);
		error(Eio);
	case 0x0C:
	case 0x12:					/* AvanstarXp */
		break;
	}

	/* check assumptions */
	n = LEUS(a->gcb->ccbn);
	if(n != 8 && n != 16){
		print("#G%d: has %d channels?\n", a->id, i);
		error(Eio);
	}
	x = a->addr + LEUS(a->gcb->ccboff);
	sz = LEUS(a->gcb->ccbsz);
	if(x+n*sz > a->addr+Pagesize){
		print("#G%d: ccb's not in 1st page\n", a->id);
		error(Eio);
	}
	for(i = 0; i < n; i++){
		ccb = (CCB*)(x + i*sz);
		if(APAGE(LEUS(ccb->inbase)) != APAGE(LEUS(ccb->inlim)) ||
		   APAGE(LEUS(ccb->outbase)) != APAGE(LEUS(ccb->outlim))){
			print("#G%d: chan buffer spans pages\n", a->id);
			error(Eio);
		}
	}

	UNLOCKPAGE(a);
	poperror();

	/* setup the channels */
	a->running = 1;
	a->nchan = i;
	a->c = smalloc(a->nchan * sizeof(Astarchan));
	for(i = 0; i < a->nchan; i++){
		ac = &a->c[i];
		ac->a = a;
		ac->ccb = (CCB*)x;
		ac->baud = 9600;	/* a100i default */
		ac->perm = 0660;
		ac->iq = qopen(4*1024, 0, astarkickin, ac);
		ac->oq = qopen(4*1024, 0, astarkick, ac);
		x += sz;
	}

	snprint(name, sizeof name, "astar%d", a->id);
	/* set up interrupt level, enable interrupts */
	if(a->pci){
		/*
		 * Which bits in the interrupt control register should be set?
		 */
		outl(a->port+PCIcontrol, 0x00031F00);
		intrenable(a->irq, astarintr, a, a->pci->tbdf, name);
	}
	else{
		c = inb(a->port+ISActl1);
		c &= ~ISAirq;
		c |= ISAien|isairqcode[a->irq];
		outb(a->port+ISActl1, c);
		intrenable(a->irq, astarintr, a, BUSUNKNOWN, name);
	}

	/* enable control program interrupt generation */
	LOCKPAGE(a, 0);
	a->gcb->cmd2 = LEUS(Gintack);
	UNLOCKPAGE(a);
}

static void
bctlwrite(Astar *a, char *cmsg)
{
	if(waserror()){
		qunlock(a);
		nexterror();
	}
	qlock(a);

	if(a->running)
		error(Eio);

	if(strncmp(cmsg, "download", 8) == 0){
		/* put board in download mode */
		downloadmode(a);