ether83815.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

		if(status & Txurn){
			ctlr->txurn++;
			ilock(&ctlr->lock);
			/* change threshold */
			iunlock(&ctlr->lock);
			status &= ~(Txurn);
		}

		ilock(&ctlr->tlock);
		while(ctlr->ntq){
			des = &ctlr->tdr[ctlr->tdri];
			cmdsts = des->cmdsts;
			if(cmdsts & Own)
				break;

			if((cmdsts & Ok) == 0){
				if(cmdsts & Txa)
					ctlr->txa++;
				if(cmdsts & Tfu)
					ctlr->tfu++;
				if(cmdsts & Td)
					ctlr->td++;
				if(cmdsts & Ed)
					ctlr->ed++;
				if(cmdsts & Owc)
					ctlr->owc++;
				if(cmdsts & Ec)
					ctlr->ec++;
#ifndef FS
				ether->oerrs++;
#endif
			}

			freeb(des->bp);
			des->bp = nil;
			des->cmdsts = 0;

			ctlr->ntq--;
			ctlr->tdri = NEXT(ctlr->tdri, ctlr->ntdr);
		}
		txstart(ether);
		iunlock(&ctlr->tlock);

		status &= ~(Txurn|Txidle|Txerr|Txdesc|Txok);

		/*
		 * Anything left not catered for?
		 */
		if(status)
			print("#l%d: status %8.8uX\n", ether->ctlrno, status);
	}
}

static void
ctlrinit(Ether* ether)
{
	Ctlr *ctlr;
	Des *des, *last;

	ctlr = ether->ctlr;

	/*
	 * Allocate suitable aligned descriptors
	 * for the transmit and receive rings;
	 * initialise the receive ring;
	 * initialise the transmit ring;
	 * unmask interrupts and start the transmit side.
	 */
	des = xspanalloc((ctlr->nrdr+ctlr->ntdr)*sizeof(Des), 32, 0);
	if(des == nil) {
		print("ns83815: ctlrinit: iallocb of descs. failed\n");
		return;
	}
	ctlr->tdr = des;
	ctlr->rdr = des+ctlr->ntdr;

	last = nil;
	for(des = ctlr->rdr; des < &ctlr->rdr[ctlr->nrdr]; des++){
		des->bp = iallocb(Rbsz);
		if(des->bp == nil)
			error(Enomem);
		des->cmdsts = Rbsz;
		des->addr = PADDR(des->bp->rp);
		if(last != nil)
			last->next = PADDR(des);
		last = des;
	}
	ctlr->rdr[ctlr->nrdr-1].next = PADDR(ctlr->rdr);
	ctlr->rdrx = 0;
	csr32w(ctlr, Rrxdp, PADDR(ctlr->rdr));

	last = nil;
	for(des = ctlr->tdr; des < &ctlr->tdr[ctlr->ntdr]; des++){
		des->cmdsts = 0;
		des->bp = nil;
		des->addr = ~0;
		if(last != nil)
			last->next = PADDR(des);
		last = des;
	}
	ctlr->tdr[ctlr->ntdr-1].next = PADDR(ctlr->tdr);
	ctlr->tdrh = 0;
	ctlr->tdri = 0;
	csr32w(ctlr, Rtxdp, PADDR(ctlr->tdr));

	txrxcfg(ctlr, Drth512);

	csr32w(ctlr, Rimr, Dperr|Sserr|Rmabt|Rtabt|Rxsovr|Hiberr|Txurn|Txerr|Txdesc|Txok|Rxorn|Rxerr|Rxdesc|Rxok);	/* Phy|Pme|Mib */
	csr32r(ctlr, Risr);	/* clear status */
	csr32w(ctlr, Rier, Ie);
err:
	;
}

static void
eeclk(Ctlr *ctlr, int clk)
{
	csr32w(ctlr, Rmear, Eesel | clk);
	microdelay(2);
}

static void
eeidle(Ctlr *ctlr)
{
	int i;

	eeclk(ctlr, 0);
	eeclk(ctlr, Eeclk);
	for(i=0; i<25; i++){
		eeclk(ctlr, 0);
		eeclk(ctlr, Eeclk);
	}
	eeclk(ctlr, 0);
	csr32w(ctlr, Rmear, 0);
	microdelay(2);
}

static int
eegetw(Ctlr *ctlr, int a)
{
	int d, i, w, v;

	eeidle(ctlr);
	eeclk(ctlr, 0);
	eeclk(ctlr, Eeclk);
	d = 0x180 | a;
	for(i=0x400; i; i>>=1){
		v = (d & i) ? Eedi : 0;
		eeclk(ctlr, v);
		eeclk(ctlr, Eeclk|v);
	}
	eeclk(ctlr, 0);

	w = 0;
	for(i=0x8000; i; i >>= 1){
		eeclk(ctlr, Eeclk);
		if(csr32r(ctlr, Rmear) & Eedo)
			w |= i;
		microdelay(2);
		eeclk(ctlr, 0);
	}
	eeidle(ctlr);
	return w;
}

static void
resetctlr(Ctlr *ctlr)
{
	int i;

	csr32w(ctlr, Rcr, Rst);
	for(i=0;; i++){
		if(i > 100)
			panic("ns83815: soft reset did not complete");
		microdelay(250);
		if((csr32r(ctlr, Rcr) & Rst) == 0)
			break;
		delay(1);
	}
}

static void
shutdown(Ether* ether)
{
	Ctlr *ctlr = ether->ctlr;

print("ether83815 shutting down\n");
	csr32w(ctlr, Rcr, Rxd|Txd);	/* disable transceiver */
	resetctlr(ctlr);
}

static void
softreset(Ctlr* ctlr, int resetphys)
{
	int i, w;

	/*
	 * Soft-reset the controller
	 */
	resetctlr(ctlr);
	csr32w(ctlr, Rccsr, Pmests);
	csr32w(ctlr, Rccsr, 0);
	csr32w(ctlr, Rcfg, csr32r(ctlr, Rcfg) | Pint_acen);

	if(resetphys){
		/*
		 * Soft-reset the PHY
		 */
		csr32w(ctlr, Rbmcr, Reset);
		for(i=0;; i++){
			if(i > 100)
				panic("ns83815: PHY soft reset time out");
			if((csr32r(ctlr, Rbmcr) & Reset) == 0)
				break;
			delay(1);
		}
	}

	/*
	 * Initialisation values, in sequence (see 4.4 Recommended Registers Configuration)
	 */
	csr16w(ctlr, 0xCC, 0x0001);	/* PGSEL */
	csr16w(ctlr, 0xE4, 0x189C);	/* PMCCSR */
	csr16w(ctlr, 0xFC, 0x0000);	/* TSTDAT */
	csr16w(ctlr, 0xF4, 0x5040);	/* DSPCFG */
	csr16w(ctlr, 0xF8, 0x008C);	/* SDCFG */

	/*
	 * Auto negotiate
	 */
	w = csr16r(ctlr, Rbmsr);	/* clear latched bits */
	debug("anar: %4.4ux\n", csr16r(ctlr, Ranar));
	csr16w(ctlr, Rbmcr, Anena);
	if(csr16r(ctlr, Ranar) == 0 || (csr32r(ctlr, Rcfg) & Aneg_dn) == 0){
		csr16w(ctlr, Rbmcr, Anena|Anrestart);
		for(i=0;; i++){
			if(i > 6000){
				print("ns83815: auto neg timed out\n");
				break;
			}
			if((w = csr16r(ctlr, Rbmsr)) & Ancomp)
				break;
			delay(1);
		}
		debug("%d ms\n", i);
		w &= 0xFFFF;
		debug("bmsr: %4.4ux\n", w);
	}
	USED(w);
	debug("anar: %4.4ux\n", csr16r(ctlr, Ranar));
	debug("anlpar: %4.4ux\n", csr16r(ctlr, Ranlpar));
	debug("aner: %4.4ux\n", csr16r(ctlr, Raner));
	debug("physts: %4.4ux\n", csr16r(ctlr, Rphysts));
	debug("tbscr: %4.4ux\n", csr16r(ctlr, Rtbscr));
}

static int
media(Ether* ether)
{
	Ctlr* ctlr;
	ulong cfg;

	ctlr = ether->ctlr;
	cfg = csr32r(ctlr, Rcfg);
	ctlr->fd = (cfg & Fdup) != 0;
	if(cfg & Speed100)
		return 100;
	if((cfg & Lnksts) == 0)
		return 100;	/* no link: use 100 to ensure larger queues */
	return 10;
}

static char* mediatable[9] = {
	"10BASE-T",				/* TP */
	"10BASE-2",				/* BNC */
	"10BASE-5",				/* AUI */
	"100BASE-TX",
	"10BASE-TFD",
	"100BASE-TXFD",
	"100BASE-T4",
	"100BASE-FX",
	"100BASE-FXFD",
};

static int
is630(ulong id, Pcidev *p)
{
	if(id == SiS900)
		switch (p->rid) {
		case SiSrev630s:
		case SiSrev630e:
	  	case SiSrev630ea1:
			return 1;
		}
	return 0;
}

enum {
	MagicReg = 0x48,
	MagicRegSz = 1,
	Magicrden = 0x40,	/* read enable, apparently */
	Paddr=		0x70,	/* address port */
	Pdata=		0x71,	/* data port */
	Pcinetctlr = 2,
};

/* rcmos() originally from LANL's SiS 900 driver's rcmos() */
static int
sisrdcmos(Ctlr *ctlr)
{
	int i;
	unsigned reg;
	ulong port;
	Pcidev *p;

	debug("ns83815: SiS 630 rev. %ux reading mac address from cmos\n", ctlr->pcidev->rid);
	p = pcimatch(nil, SiS, SiS630bridge);
	if(p == nil) {
		print("ns83815: no SiS 630 rev. %ux bridge for mac addr\n",
			ctlr->pcidev->rid);
		return 0;
	}
	port = p->mem[0].bar & ~0x01;
	debug("ns83815: SiS 630 rev. %ux reading mac addr from cmos via bridge at port 0x%lux\n", ctlr->pcidev->rid, port);

	reg = pcicfgr8(p, MagicReg);
	pcicfgw8(p, MagicReg, reg|Magicrden);

	for (i = 0; i < Eaddrlen; i++) {
		outb(port+Paddr, SiS630eenodeaddr + i);
		ctlr->sromea[i] = inb(port+Pdata);
	}

	pcicfgw8(p, MagicReg, reg & ~Magicrden);
	return 1;
}

/*
 * If this is a SiS 630E chipset with an embedded SiS 900 controller,
 * we have to read the MAC address from the APC CMOS RAM. - sez freebsd.
 * However, CMOS *is* NVRAM normally.  See devrtc.c:440, memory.c:88.
 */
static void
sissrom(Ctlr *ctlr)
{
	union {
		uchar	eaddr[Eaddrlen];
		ushort	alignment;
	} ee;
	int i, off = SiSeenodeaddr, cnt = sizeof ee.eaddr / sizeof(short);
	ushort *shp = (ushort *)ee.eaddr;

	if(!is630(ctlr->id, ctlr->pcidev) || !sisrdcmos(ctlr)) {
		for (i = 0; i < cnt; i++)
			*shp++ = eegetw(ctlr, off++);
		memmove(ctlr->sromea, ee.eaddr, sizeof ctlr->sromea);
	}
}

static void
nssrom(Ctlr* ctlr)
{
	int i, j;

	for(i = 0; i < nelem(ctlr->srom); i++)
		ctlr->srom[i] = eegetw(ctlr, i);

	/*
	 * the MAC address is reversed, straddling word boundaries
	 */
	j = Nseenodeaddr*16 + 15;
	for(i=0; i<48; i++){
		ctlr->sromea[i>>3] |= ((ctlr->srom[j>>4] >> (15-(j&0xF))) & 1) << (i&7);
		j++;
	}
}

static void
srom(Ctlr* ctlr)
{
	memset(ctlr->sromea, 0, sizeof(ctlr->sromea));
	switch (ctlr->id) {
	case SiS900:
	case SiS7016:
		sissrom(ctlr);
		break;
	case Nat83815:
		nssrom(ctlr);
		break;
	default:
		print("ns83815: srom: unknown id 0x%ux\n", ctlr->id);
		break;
	}
}

static void
scanpci83815(void)
{
	Ctlr *ctlr;
	Pcidev *p;
	ulong id;

	p = nil;
	while(p = pcimatch(p, 0, 0)){
		/* ccru is a short in the FS kernel, thus the cast to uchar */
		if (p->ccrb != Pcinetctlr || (uchar)p->ccru != 0)
			continue;		/* not a nic */
		id = (p->did<<16)|p->vid;
		switch(id){
		default:
			continue;
		case Nat83815:
		case SiS900:
			break;
		}

		/*
		 * bar[0] is the I/O port register address and
		 * bar[1] is the memory-mapped register address.
		 */
		ctlr = mallocz(sizeof(Ctlr), 1);
		ctlr->port = p->mem[0].bar & ~0x01;
		ctlr->pcidev = p;
		ctlr->id = id;

		if(ioalloc(ctlr->port, p->mem[0].size, 0, "ns83815") < 0){
			print("ns83815: port 0x%uX in use\n", ctlr->port);
			free(ctlr);
			continue;
		}

		softreset(ctlr, 0);
		srom(ctlr);

		if(ctlrhead != nil)
			ctlrtail->next = ctlr;
		else
			ctlrhead = ctlr;
		ctlrtail = ctlr;
	}
}

/* multicast already on, don't need to do anything */
static void
multicast(void*, uchar*, int)
{
}

int
dp83815reset(Ether* ether)
{
	Ctlr *ctlr;
	int i, x;
	ulong ctladdr;
	uchar ea[Eaddrlen];
	static int scandone;

	if(scandone == 0){
		scanpci83815();
		scandone = 1;
	}

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

	ether->ctlr = ctlr;
	ether->port = ctlr->port;
	ether->irq = ctlr->pcidev->intl;
	ether->tbdf = ctlr->pcidev->tbdf;

	/*
	 * Check if the adapter's station address is to be overridden.
	 * If not, read it from the EEPROM and set in ether->ea prior to
	 * loading the station address in the hardware.
	 */
	memset(ea, 0, Eaddrlen);
	if(memcmp(ea, ether->ea, Eaddrlen) == 0)
		memmove(ether->ea, ctlr->sromea, Eaddrlen);
	for(i=0; i<Eaddrlen; i+=2){
		x = ether->ea[i] | (ether->ea[i+1]<<8);
		ctladdr = (ctlr->id == Nat83815? i: i<<15);
		csr32w(ctlr, Rrfcr, ctladdr);
		csr32w(ctlr, Rrfdr, x);
	}
	csr32w(ctlr, Rrfcr, Rfen|Apm|Aab|Aam);

	ether->mbps = media(ether);

	/*
	 * Look for a medium override in case there's no autonegotiation
	 * the autonegotiation fails.
	 */

	for(i = 0; i < ether->nopt; i++){
		if(cistrcmp(ether->opt[i], "FD") == 0){
			ctlr->fd = 1;
			continue;
		}
		for(x = 0; x < nelem(mediatable); x++){
			debug("compare <%s> <%s>\n", mediatable[x],
				ether->opt[i]);
			if(cistrcmp(mediatable[x], ether->opt[i]) == 0){
				if(x != 4 && x >= 3)
					ether->mbps = 100;
				else
					ether->mbps = 10;
				switch(x){
				default:
					ctlr->fd = 0;
					break;

				case 0x04:		/* 10BASE-TFD */
				case 0x05:		/* 100BASE-TXFD */
				case 0x08:		/* 100BASE-FXFD */
					ctlr->fd = 1;
					break;
				}
				break;
			}
		}
	}

	/*
	 * Initialise descriptor rings, ethernet address.
	 */
	ctlr->nrdr = Nrde;
	ctlr->ntdr = Ntde;
	pcisetbme(ctlr->pcidev);
	ctlrinit(ether);

	/*
	 * Linkage to the generic ethernet driver.
	 */
	ether->attach = attach;
	ether->transmit = transmit;
	ether->interrupt = interrupt;
#ifndef FS
	ether->ifstat = ifstat;

	ether->arg = ether;
	ether->promiscuous = promiscuous;
	ether->multicast = multicast;
	ether->shutdown = shutdown;
#endif
	debug("ns83815: dp83815reset: done\n");
	return 0;
}

#ifndef FS
void
ether83815link(void)
{
	addethercard("83815",  dp83815reset);
}
#endif