usbuhci.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

	uh = a;
	ctlr = uh->ctlr;
	s = IN(Status);
	ctlr->frameptr = inl(ctlr->io+Flbaseadd);
	ctlr->framenumber = IN(Frnum) & 0x3ff;
	OUT(Status, s);
	if ((s & 0x1f) == 0)
		return;
	ctlr->usbints++;
	frnum = IN(Frnum) & 0x3ff;
	if (s & 0x1a) {
		XPRINT("cmd #%x sofmod #%x\n", IN(Cmd), inb(ctlr->io+SOFMod));
		XPRINT("sc0 #%x sc1 #%x\n", IN(Portsc0), IN(Portsc1));
	}

	ilock(&ctlr->activends);
	for(e = ctlr->activends.f; e != nil; e = e->activef) {
		x = e->private;
		if(!e->iso && x->epq != nil) {
			XXPRINT("cleanq(ctlr, x->epq, 0, 0)\n");
			cleanq(ctlr, x->epq, 0, 0);
		}
		if(e->iso) {
			XXPRINT("cleaniso(e)\n");
			cleaniso(e, frnum);
		}
	}
	iunlock(&ctlr->activends);
	XXPRINT("cleanq(ctlr, ctlr->ctlq, 0, 0)\n");
	cleanq(ctlr, ctlr->ctlq, 0, 0);
	XXPRINT("cleanq(ctlr, ctlr->bulkq, 0, Vf)\n");
	cleanq(ctlr, ctlr->bulkq, 0, Vf);
	XXPRINT("clean recvq\n");
	for (q = ctlr->recvq->next; q; q = q->hlink) {
		XXPRINT("cleanq(ctlr, q, 0, Vf)\n");
		cleanq(ctlr, q, 0, Vf);
	}
}

static int
eptinput(void *arg)
{
	Endpt *e;

	e = arg;
	return e->eof || e->err || qcanread(e->rq);
}

static int
isoready(void *a)
{
	Endptx *x;
	TD *etd;

	x = a;
	return (etd = x->etd) == nil || (etd != x->xtd && (etd->status & Active) == 0);
}

static long
isoio(Ctlr *ctlr, Endpt *e, void *a, long n, ulong offset, int w)
{
	TD *td;
	Endptx *x;
	int i, frnum;
	uchar *p, *q, *bp;
	volatile int isolock;

	x = e->private;
	qlock(&e->rlock);
	isolock = 0;
	if(waserror()){
		if (isolock){
			isolock = 0;
			iunlock(&ctlr->activends);
		}
		qunlock(&e->rlock);
		eptcancel(ctlr, e);
		nexterror();
	}
	p = a;
	if (offset != 0 && offset != e->foffset){
		iprint("offset %lud, foffset %lud\n", offset, e->foffset);
		/* Seek to a specific position */
		frnum = (IN(Frnum) + 8) & 0x3ff;
		td = x->td0 +frnum;
		if (offset < td->offset)
			error("ancient history");
		while (offset > e->toffset){
			tsleep(&e->wr, return0, 0, 500);
		}
		while (offset >= td->offset + ((w?(td->dev >> 21):td->status) + 1) & 0x7ff){
			td = td->next;
			if (td == x->xtd)
				iprint("trouble\n");
		}
		ilock(&ctlr->activends);
		isolock = 1;
		e->off = td->offset - offset;
		if (e->off >= e->maxpkt){
			iprint("I can't program: %d\n", e->off);
			e->off = 0;
		}
		x->etd = td;
		e->foffset = offset;
	}
	do {
		if (isolock == 0){
			ilock(&ctlr->activends);
			isolock = 1;
		}
		td = x->etd;
		if (td == nil || e->off == 0){
			if (td == nil){
				XPRINT("0");
				if (w){
					frnum = (IN(Frnum) + 1) & 0x3ff;
					td = x->td0 + frnum;
					while(td->status & Active)
						td = td->next;
				}else{
					frnum = (IN(Frnum) - 4) & 0x3ff;
					td = x->td0 + frnum;
					while(td->next != x->xtd)
						td = td->next;
				}
				x->etd = td;
				e->off = 0;
			}else{
				/* New td, make sure it's ready */
				while (isoready(x) == 0){
					isolock = 0;
					iunlock(&ctlr->activends);
					sleep(&e->wr, isoready, x);
					ilock(&ctlr->activends);
					isolock = 1;
				}
				if (x->etd == nil){
					XPRINT("!");
					continue;
				}
			}
			if (w)
				e->psize = ((td->dev >> 21) + 1) & 0x7ff;
			else
				e->psize = (x->etd->status + 1) & 0x7ff;
			if(e->psize > e->maxpkt)
				panic("packet size > maximum");
		}
		if((i = n) >= e->psize)
			i = e->psize;
		if (w)
			e->buffered += i;
		else{
			e->buffered -= i;
			if (e->buffered < 0)
				e->buffered = 0;
		}
		isolock = 0;
		iunlock(&ctlr->activends);
		td->flags &= ~IsoClean;
		bp = x->bp0 + (td - x->td0) * e->maxpkt / e->pollms;
		q = bp + e->off;
		if (w){
			memmove(q, p, i);
		}else{
			memmove(p, q, i);
		}
		p += i;
		n -= i;
		e->off += i;
		e->psize -= i;
		if (e->psize){
			if (n != 0)
				panic("usb iso: can't happen");
			break;
		}
		if(w)
			td->offset = offset + (p-(uchar*)a) - (((td->dev >> 21) + 1) & 0x7ff);
		td->status = ErrLimit3 | Active | IsoSelect | IOC;
		x->etd = td->next;
		e->off = 0;
	} while(n > 0);
	n = p-(uchar*)a;
	e->foffset += n;
	poperror();
	if (isolock)
		iunlock(&ctlr->activends);
	qunlock(&e->rlock);
	return n;
}

static long
read(Usbhost *uh, Endpt *e, void *a, long n, vlong offset)
{
	long l, i;
	Block *b;
	Ctlr *ctlr;
	uchar *p;

	ctlr = uh->ctlr;
	if(e->iso)
		return isoio(ctlr, e, a, n, (ulong)offset, 0);

	XPRINT("qlock(%p)\n", &e->rlock);
	qlock(&e->rlock);
	XPRINT("got qlock(%p)\n", &e->rlock);
	if(waserror()){
		qunlock(&e->rlock);
		eptcancel(ctlr, e);
		nexterror();
	}
	p = a;
	do {
		if(e->eof) {
			XPRINT("e->eof\n");
			break;
		}
		if(e->err)
			error(e->err);
		qrcv(ctlr, e);
		if(!e->iso)
			e->rdata01 ^= 1;
		sleep(&e->rr, eptinput, e);
		if(e->err)
			error(e->err);
		b = qget(e->rq);	/* TO DO */
		if(b == nil) {
			XPRINT("b == nil\n");
			break;
		}
		if(waserror()){
			freeb(b);
			nexterror();
		}
		l = BLEN(b);
		if((i = l) > n)
			i = n;
		if(i > 0){
			memmove(p, b->rp, i);
			p += i;
		}
		poperror();
		freeb(b);
		n -= i;
		if (l != e->maxpkt)
			break;
	} while (n > 0);
	poperror();
	qunlock(&e->rlock);
	return p-(uchar*)a;
}

static int
qisempty(void *arg)
{
	return ((QH*)arg)->entries & Terminate;
}

static long
write(Usbhost *uh, Endpt *e, void *a, long n, vlong offset, int tok)
{
	int i, j;
	QH *qh;
	Block *b;
	Ctlr *ctlr;
	uchar *p;

	ctlr = uh->ctlr;
	if(e->iso)
		return isoio(ctlr, e, a, n, (ulong)offset, 1);

	p = a;
	qlock(&e->wlock);
	if(waserror()){
		qunlock(&e->wlock);
		eptcancel(ctlr, e);
		nexterror();
	}
	do {
		if(e->err)
			error(e->err);
		if((i = n) >= e->maxpkt)
			i = e->maxpkt;
		b = allocb(i);
		if(waserror()){
			freeb(b);
			nexterror();
		}
		XPRINT("out [%d]", i);
		for (j = 0; j < i; j++) XPRINT(" %.2x", p[j]);
		XPRINT("\n");
		memmove(b->wp, p, i);
		b->wp += i;
		p += i;
		n -= i;
		poperror();
		qh = qxmit(ctlr, e, b, tok);
		tok = TokOUT;
		e->wdata01 ^= 1;
		if(e->ntd >= e->nbuf) {
XPRINT("qh %s: q=%p first=%p last=%p entries=%.8lux\n",
 "writeusb sleep", qh, qh->first, qh->last, qh->entries);
			XPRINT("write: sleep %lux\n", &e->wr);
			sleep(&e->wr, qisempty, qh);
			XPRINT("write: awake\n");
		}
	} while(n > 0);
	poperror();
	qunlock(&e->wlock);
	return p-(uchar*)a;
}

static void
init(Usbhost* uh)
{
	Ctlr *ctlr;

	ctlr = uh->ctlr;
	ilock(ctlr);
	outl(ctlr->io+Flbaseadd, PCIWADDR(ctlr->frames));
	OUT(Frnum, 0);
	OUT(Usbintr, 0xF);	/* enable all interrupts */
	XPRINT("cmd 0x%x sofmod 0x%x\n", IN(Cmd), inb(ctlr->io+SOFMod));
	XPRINT("sc0 0x%x sc1 0x%x\n", IN(Portsc0), IN(Portsc1));
	if((IN(Cmd)&1)==0)
		OUT(Cmd, 1);	/* run */
//	pprint("at: c=%x s=%x c0=%x\n", IN(Cmd), IN(Status), IN(Portsc0));
	iunlock(ctlr);
}

static void
scanpci(void)
{
	int io;
	Ctlr *ctlr;
	Pcidev *p;
	static int already = 0;

	if(already)
		return;
	already = 1;
	p = nil;
	while(p = pcimatch(p, 0, 0)) {
		/*
		 * Find UHCI controllers.  Class = 12 (serial controller),
		 * Sub-class = 3 (USB) and Programming Interface = 0.
		 */
		if(p->ccrb != 0x0C || p->ccru != 0x03)
			continue;
		switch(p->ccrp){
		case 0x00:
			io = p->mem[4].bar & ~0x0F;
			break;
		case 0x10:
		case 0x20:
			print("usb%chci: %x/%x %sport 0x%lux size 0x%x irq %d (ignored)\n",
				(p->ccrp == 0x10? 'o': 'e'), p->vid, p->did,
				(p->ccrp == 0x10? "": "USB 2 "),
				p->mem[0].bar & ~0x0F, p->mem[0].size, p->intl);
			/* fallthrough */
		default:
			continue;
		}
		if(io == 0) {
			print("usbuhci: failed to map registers\n");
			continue;
		}
		if(ioalloc(io, p->mem[4].size, 0, "usbuhci") < 0){
			print("usbuhci: port %d in use\n", io);
			continue;
		}
		if(p->intl == 0xFF || p->intl == 0) {
			print("usbuhci: no irq assigned for port %d\n", io);
			continue;
		}

		XPRINT("usbuhci: %x/%x port 0x%ux size 0x%x irq %d\n",
			p->vid, p->did, io, p->mem[4].size, p->intl);

		ctlr = malloc(sizeof(Ctlr));
		ctlr->pcidev = p;
		ctlr->io = io;
		if(ctlrhead != nil)
			ctlrtail->next = ctlr;
		else
			ctlrhead = ctlr;
		ctlrtail = ctlr;
	}
}

static int
reset(Usbhost *uh)
{
	int i;
	TD *t;
	ulong io;
	Ctlr *ctlr;
	Pcidev *p;

	scanpci();

	/*
	 * Any adapter matches if no uh->port is supplied,
	 * otherwise the ports must match.
	 */
	for(ctlr = ctlrhead; ctlr != nil; ctlr = ctlr->next){
		if(ctlr->active)
			continue;
		if(uh->port == 0 || uh->port == ctlr->io){
			ctlr->active = 1;
			break;
		}
	}
	if(ctlr == nil)
		return -1;

	io = ctlr->io;
	p = ctlr->pcidev;

	uh->ctlr = ctlr;
	uh->port = io;
	uh->irq = p->intl;
	uh->tbdf = p->tbdf;

	XPRINT("usbcmd\t0x%.4x\nusbsts\t0x%.4x\nusbintr\t0x%.4x\nfrnum\t0x%.2x\n",
		IN(Cmd), IN(Status), IN(Usbintr), inb(io+Frnum));
	XPRINT("frbaseadd\t0x%.4x\nsofmod\t0x%x\nportsc1\t0x%.4x\nportsc2\t0x%.4x\n",
		IN(Flbaseadd), inb(io+SOFMod), IN(Portsc0), IN(Portsc1));

	OUT(Cmd, 0);					/* stop */
	while((IN(Status) & (1<<5)) == 0)	/* wait for halt */
		;
	OUT(Status, 0xFF);				/* clear pending interrupts */
	pcicfgw16(p, 0xc0, 0x2000);		/* legacy support register: turn off lunacy mode */

	if(0){
		i = inb(io+SOFMod);
		OUT(Cmd, 4);	/* global reset */
		delay(15);
		OUT(Cmd, 0);	/* end reset */
		delay(4);
		outb(io+SOFMod, i);
	}

	ctlr->tdpool = xspanalloc(128*sizeof(TD), 16, 0);
	for(i=128; --i>=0;){
		ctlr->tdpool[i].next = ctlr->freetd;
		ctlr->freetd = &ctlr->tdpool[i];
	}
	ctlr->qhpool = xspanalloc(64*sizeof(QH), 16, 0);
	for(i=64; --i>=0;){
		ctlr->qhpool[i].next = ctlr->freeqh;
		ctlr->freeqh = &ctlr->qhpool[i];
	}

	/*
	 * the last entries of the periodic (interrupt & isochronous) scheduling TD entries
	 * points to the control queue and the bandwidth sop for bulk traffic.
	 * this is looped following the instructions in PIIX4 errata 29773804.pdf:
	 * a QH links to a looped but inactive TD as its sole entry,
	 * with its head entry leading on to the bulk traffic, the last QH of which
	 * links back to the empty QH.
	 */
	ctlr->ctlq = allocqh(ctlr);
	ctlr->bwsop = allocqh(ctlr);
	ctlr->bulkq = allocqh(ctlr);
	ctlr->recvq = allocqh(ctlr);
	t = alloctd(ctlr);	/* inactive TD, looped */
	t->link = PCIWADDR(t);
	ctlr->bwsop->entries = PCIWADDR(t);

	ctlr->ctlq->head = PCIWADDR(ctlr->bulkq) | IsQH;
	ctlr->bulkq->head = PCIWADDR(ctlr->recvq) | IsQH;
	ctlr->recvq->head = PCIWADDR(ctlr->bwsop) | IsQH;
	if (1)	/* don't use loop back */
 		ctlr->bwsop->head = Terminate;
	else	/* set up loop back */
		ctlr->bwsop->head = PCIWADDR(ctlr->bwsop) | IsQH;

	ctlr->frames = xspanalloc(FRAMESIZE, FRAMESIZE, 0);
	ctlr->frameld = xallocz(FRAMESIZE, 1);
	for (i = 0; i < NFRAME; i++)
		ctlr->frames[i] = PCIWADDR(ctlr->ctlq) | IsQH;

	/*
	 * Linkage to the generic USB driver.
	 */
	uh->init = init;
	uh->interrupt = interrupt;

	uh->portinfo = portinfo;
	uh->portreset = portreset;
	uh->portenable = portenable;

	uh->epalloc = epalloc;
	uh->epfree = epfree;
	uh->epopen = epopen;
	uh->epclose = epclose;
	uh->epmode = epmode;

	uh->read = read;
	uh->write = write;

	return 0;
}

void
usbuhcilink(void)
{
	addusbtype("uhci", reset);
}