ether82557.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

			rfd->field = 0;
		}

		/*
		 * The ring tail pointer follows the head with with one
		 * unused buffer in between to defeat hardware prefetch;
		 * once the tail pointer has been bumped on to the next
		 * and the new tail has the Suspend bit set, it can be
		 * removed from the old tail buffer.
		 * As a replacement for the current head buffer may have
		 * been allocated above, ensure that the new tail points
		 * to it (next and link).
		 */
		rfd = (Rfd*)ctlr->rfdtail->rp;
		ctlr->rfdtail = ctlr->rfdtail->next;
		ctlr->rfdtail->next = bp;
		((Rfd*)ctlr->rfdtail->rp)->link = PADDR(bp->rp);
		((Rfd*)ctlr->rfdtail->rp)->field |= RfdS;
		coherence();
		rfd->field &= ~RfdS;

		/*
		 * Finally done with the current (possibly replaced)
		 * head, move on to the next and maintain the sentinel
		 * between tail and head.
		 */
		ctlr->rfdhead = bp->next;
		bp = ctlr->rfdhead;
	}
}

static void
interrupt(Ureg*, void* arg)
{
	Cb* cb;
	Ctlr *ctlr;
	Ether *ether;
	int status;

	ether = arg;
	ctlr = ether->ctlr;

	for(;;){
		ilock(&ctlr->rlock);
		status = csr16r(ctlr, Status);
		csr8w(ctlr, Ack, (status>>8) & 0xFF);
		iunlock(&ctlr->rlock);

		if(!(status & (StatCX|StatFR|StatCNA|StatRNR|StatMDI|StatSWI)))
			break;

		/*
		 * If the watchdog timer for the receiver lockup errata is running,
		 * let it know the receiver is active.
		 */
		if(status & (StatFR|StatRNR)){
			ilock(&ctlr->cblock);
			ctlr->tick = 0;
			iunlock(&ctlr->cblock);
		}

		if(status & StatFR){
			receive(ether);
			status &= ~StatFR;
		}

		if(status & StatRNR){
			command(ctlr, RUresume, 0);
			status &= ~StatRNR;
		}

		if(status & StatCNA){
			ilock(&ctlr->cblock);

			cb = ctlr->cbtail;
			while(ctlr->cbq){
				if(!(cb->status & CbC))
					break;
				if(cb->bp){
					freeb(cb->bp);
					cb->bp = nil;
				}
				if((cb->status & CbU) && ctlr->threshold < 0xE0)
					ctlr->threshold++;

				ctlr->cbq--;
				cb = cb->next;
			}
			ctlr->cbtail = cb;

			txstart(ether);
			iunlock(&ctlr->cblock);

			status &= ~StatCNA;
		}

		if(status & (StatCX|StatFR|StatCNA|StatRNR|StatMDI|StatSWI))
			panic("#l%d: status %#ux\n", ether->ctlrno, status);
	}
}

static void
ctlrinit(Ctlr* ctlr)
{
	int i;
	Block *bp;
	Rfd *rfd;
	ulong link;

	/*
	 * Create the Receive Frame Area (RFA) as a ring of allocated
	 * buffers.
	 * A sentinel buffer is maintained between the last buffer in
	 * the ring (marked with RfdS) and the head buffer to defeat the
	 * hardware prefetch of the next RFD and allow dynamic buffer
	 * allocation.
	 */
	link = NullPointer;
	for(i = 0; i < Nrfd; i++){
		bp = rfdalloc(link);
		if(ctlr->rfdhead == nil)
			ctlr->rfdtail = bp;
		bp->next = ctlr->rfdhead;
		ctlr->rfdhead = bp;
		link = PADDR(bp->rp);
	}
	ctlr->rfdtail->next = ctlr->rfdhead;
	rfd = (Rfd*)ctlr->rfdtail->rp;
	rfd->link = PADDR(ctlr->rfdhead->rp);
	rfd->field |= RfdS;
	ctlr->rfdhead = ctlr->rfdhead->next;

	/*
	 * Create a ring of control blocks for the
	 * transmit side.
	 */
	ilock(&ctlr->cblock);
	ctlr->cbr = malloc(ctlr->ncb*sizeof(Cb));
	for(i = 0; i < ctlr->ncb; i++){
		ctlr->cbr[i].status = CbC|CbOK;
		ctlr->cbr[i].command = CbS|CbNOP;
		ctlr->cbr[i].link = PADDR(&ctlr->cbr[NEXT(i, ctlr->ncb)].status);
		ctlr->cbr[i].next = &ctlr->cbr[NEXT(i, ctlr->ncb)];
	}
	ctlr->cbhead = ctlr->cbr;
	ctlr->cbtail = ctlr->cbr;
	ctlr->cbq = 0;

	memmove(ctlr->configdata, configdata, sizeof(configdata));
	ctlr->threshold = 80;
	ctlr->tick = 0;

	iunlock(&ctlr->cblock);
}

static int
miir(Ctlr* ctlr, int phyadd, int regadd)
{
	int mcr, timo;

	lock(&ctlr->miilock);
	csr32w(ctlr, Mcr, MDIread|(phyadd<<21)|(regadd<<16));
	mcr = 0;
	for(timo = 64; timo; timo--){
		mcr = csr32r(ctlr, Mcr);
		if(mcr & MDIready)
			break;
		microdelay(1);
	}
	unlock(&ctlr->miilock);

	if(mcr & MDIready)
		return mcr & 0xFFFF;

	return -1;
}

static int
miiw(Ctlr* ctlr, int phyadd, int regadd, int data)
{
	int mcr, timo;

	lock(&ctlr->miilock);
	csr32w(ctlr, Mcr, MDIwrite|(phyadd<<21)|(regadd<<16)|(data & 0xFFFF));
	mcr = 0;
	for(timo = 64; timo; timo--){
		mcr = csr32r(ctlr, Mcr);
		if(mcr & MDIready)
			break;
		microdelay(1);
	}
	unlock(&ctlr->miilock);

	if(mcr & MDIready)
		return 0;

	return -1;
}

static int
hy93c46r(Ctlr* ctlr, int r)
{
	int data, i, op, size;

	/*
	 * Hyundai HY93C46 or equivalent serial EEPROM.
	 * This sequence for reading a 16-bit register 'r'
	 * in the EEPROM is taken straight from Section
	 * 3.3.4.2 of the Intel 82557 User's Guide.
	 */
reread:
	csr16w(ctlr, Ecr, EEcs);
	op = EEstart|EEread;
	for(i = 2; i >= 0; i--){
		data = (((op>>i) & 0x01)<<2)|EEcs;
		csr16w(ctlr, Ecr, data);
		csr16w(ctlr, Ecr, data|EEsk);
		microdelay(1);
		csr16w(ctlr, Ecr, data);
		microdelay(1);
	}

	/*
	 * First time through must work out the EEPROM size.
	 */
	if((size = ctlr->eepromsz) == 0)
		size = 8;

	for(size = size-1; size >= 0; size--){
		data = (((r>>size) & 0x01)<<2)|EEcs;
		csr16w(ctlr, Ecr, data);
		csr16w(ctlr, Ecr, data|EEsk);
		delay(1);
		csr16w(ctlr, Ecr, data);
		microdelay(1);
		if(!(csr16r(ctlr, Ecr) & EEdo))
			break;
	}

	data = 0;
	for(i = 15; i >= 0; i--){
		csr16w(ctlr, Ecr, EEcs|EEsk);
		microdelay(1);
		if(csr16r(ctlr, Ecr) & EEdo)
			data |= (1<<i);
		csr16w(ctlr, Ecr, EEcs);
		microdelay(1);
	}

	csr16w(ctlr, Ecr, 0);

	if(ctlr->eepromsz == 0){
		ctlr->eepromsz = 8-size;
		ctlr->eeprom = malloc((1<<ctlr->eepromsz)*sizeof(ushort));
		goto reread;
	}

	return data;
}

static void
i82557pci(void)
{
	Pcidev *p;
	Ctlr *ctlr;
	int nop, port;

	p = nil;
	nop = 0;
	while(p = pcimatch(p, 0x8086, 0)){
		switch(p->did){
		default:
			continue;
		case 0x1031:		/* Intel 82562EM */
		case 0x1050:		/* Intel 82562EZ */
		case 0x1039:		/* Intel 82801BD PRO/100 VE */
		case 0x103A:		/* Intel 82562 PRO/100 VE */
		case 0x103D:		/* Intel 82562 PRO/100 VE */
		case 0x1064:		/* Intel 82562 PRO/100 VE */
		case 0x2449:		/* Intel 82562ET */
			nop = 1;
			/*FALLTHROUGH*/
		case 0x1209:		/* Intel 82559ER */
		case 0x1229:		/* Intel 8255[789] */
		case 0x1030:		/* Intel 82559 InBusiness 10/100  */
			break;
		}
#ifndef FS
		if(pcigetpms(p) > 0){
			int i;

			pcisetpms(p, 0);
	
			for(i = 0; i < 6; i++)
				pcicfgw32(p, PciBAR0+i*4, p->mem[i].bar);
			pcicfgw8(p, PciINTL, p->intl);
			pcicfgw8(p, PciLTR, p->ltr);
			pcicfgw8(p, PciCLS, p->cls);
			pcicfgw16(p, PciPCR, p->pcr);
		}
#endif
		/*
		 * bar[0] is the memory-mapped register address (4KB),
		 * bar[1] is the I/O port register address (32 bytes) and
		 * bar[2] is for the flash ROM (1MB).
		 */
		port = p->mem[1].bar & ~0x01;
		if(ioalloc(port, p->mem[1].size, 0, "i82557") < 0){
			print("i82557: port %#ux in use\n", port);
			continue;
		}

		ctlr = malloc(sizeof(Ctlr));
		ctlr->port = port;
		ctlr->pcidev = p;
		ctlr->nop = nop;

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

		pcisetbme(p);
	}
}

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
scanphy(Ctlr* ctlr)
{
	int i, oui, x;

	for(i = 0; i < 32; i++){
		if((oui = miir(ctlr, i, 2)) == -1 || oui == 0 || oui == 0xFFFF)
			continue;
		oui <<= 6;
		x = miir(ctlr, i, 3);
		oui |= x>>10;
		//print("phy%d: oui %#ux reg1 %#ux\n", i, oui, miir(ctlr, i, 1));

		ctlr->eeprom[6] = i;
		if(oui == 0xAA00)
			ctlr->eeprom[6] |= 0x07<<8;
		else if(oui == 0x80017){
			if(x & 0x01)
				ctlr->eeprom[6] |= 0x0A<<8;
			else
				ctlr->eeprom[6] |= 0x04<<8;
		}
		return i;
	}
	return -1;
}

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

print("ether82557 shutting down\n");
	csr32w(ctlr, Port, 0);
	delay(1);
	csr8w(ctlr, Interrupt, InterruptM);
}


int
etheri82557reset(Ether* ether)
{
	int anar, anlpar, bmcr, bmsr, i, k, medium, phyaddr, x;
	unsigned short sum;
	uchar ea[Eaddrlen];
	Ctlr *ctlr;

	if(ctlrhead == nil)
		i82557pci();

	/*
	 * 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;

	/*
	 * Initialise the Ctlr structure.
	 * Perform a software reset after which should ensure busmastering
	 * is still enabled. The EtherExpress PRO/100B appears to leave
	 * the PCI configuration alone (see the 'To do' list above) so punt
	 * for now.
	 * Load the RUB and CUB registers for linear addressing (0).
	 */
	ether->ctlr = ctlr;
	ether->port = ctlr->port;
	ether->irq = ctlr->pcidev->intl;
	ether->tbdf = ctlr->pcidev->tbdf;

	ilock(&ctlr->rlock);
	csr32w(ctlr, Port, 0);
	delay(1);
	csr8w(ctlr, Interrupt, InterruptM);
	iunlock(&ctlr->rlock);

	command(ctlr, LoadRUB, 0);
	command(ctlr, LoadCUB, 0);
	command(ctlr, LoadDCA, PADDR(ctlr->dump));

	/*
	 * Initialise the receive frame, transmit ring and configuration areas.
	 */
	ctlr->ncb = Ncb;
	ctlrinit(ctlr);

	/*
	 * Read the EEPROM.
	 * Do a dummy read first to get the size
	 * and allocate ctlr->eeprom.
	 */
	hy93c46r(ctlr, 0);
	sum = 0;
	for(i = 0; i < (1<<ctlr->eepromsz); i++){
		x = hy93c46r(ctlr, i);
		ctlr->eeprom[i] = x;
		sum += x;
	}
	if(sum != 0xBABA)
		print("#l%d: EEPROM checksum - %#4.4ux\n", ether->ctlrno, sum);

	/*
	 * Eeprom[6] indicates whether there is a PHY and whether
	 * it's not 10Mb-only, in which case use the given PHY address
	 * to set any PHY specific options and determine the speed.
	 * Unfortunately, sometimes the EEPROM is blank except for
	 * the ether address and checksum; in this case look at the
	 * controller type and if it's am 82558 or 82559 it has an
	 * embedded PHY so scan for that.
	 * If no PHY, assume 82503 (serial) operation.
	 */
	if((ctlr->eeprom[6] & 0x1F00) && !(ctlr->eeprom[6] & 0x8000))
		phyaddr = ctlr->eeprom[6] & 0x00FF;
	else
	switch(ctlr->pcidev->rid){
	case 0x01:			/* 82557 A-step */
	case 0x02:			/* 82557 B-step */
	case 0x03:			/* 82557 C-step */
	default:
		phyaddr = -1;
		break;
	case 0x04:			/* 82558 A-step */
	case 0x05:			/* 82558 B-step */
	case 0x06:			/* 82559 A-step */
	case 0x07:			/* 82559 B-step */
	case 0x08:			/* 82559 C-step */
	case 0x09:			/* 82559ER A-step */
		phyaddr = scanphy(ctlr);
		break;
	}
	if(phyaddr >= 0){
		/*
		 * Resolve the highest common ability of the two
		 * link partners. In descending order:
		 *	0x0100		100BASE-TX Full Duplex
		 *	0x0200		100BASE-T4
		 *	0x0080		100BASE-TX
		 *	0x0040		10BASE-T Full Duplex
		 *	0x0020		10BASE-T
		 */
		anar = miir(ctlr, phyaddr, 0x04);
		anlpar = miir(ctlr, phyaddr, 0x05) & 0x03E0;
		anar &= anlpar;
		bmcr = 0;
		if(anar & 0x380)
			bmcr = 0x2000;
		if(anar & 0x0140)
			bmcr |= 0x0100;

		switch((ctlr->eeprom[6]>>8) & 0x001F){

		case 0x04:				/* DP83840 */
		case 0x0A:				/* DP83840A */
			/*
			 * The DP83840[A] requires some tweaking for
			 * reliable operation.
			 * The manual says bit 10 should be unconditionally
			 * set although it supposedly only affects full-duplex
			 * operation (an & 0x0140).
			 */
			x = miir(ctlr, phyaddr, 0x17) & ~0x0520;
			x |= 0x0420;
			for(i = 0; i < ether->nopt; i++){
				if(cistrcmp(ether->opt[i], "congestioncontrol"))
					continue;
				x |= 0x0100;
				break;
			}
			miiw(ctlr, phyaddr, 0x17, x);

			/*
			 * If the link partner can't autonegotiate, determine
			 * the speed from elsewhere.
			 */
			if(anlpar == 0){
				miir(ctlr, phyaddr, 0x01);
				bmsr = miir(ctlr, phyaddr, 0x01);
				x = miir(ctlr, phyaddr, 0x19);
				if((bmsr & 0x0004) && !(x & 0x0040))
					bmcr = 0x2000;
			}
			break;

		case 0x07:				/* Intel 82555 */
			/*
			 * Auto-negotiation may fail if the other end is
			 * a DP83840A and the cable is short.
			 */
			miir(ctlr, phyaddr, 0x01);
			bmsr = miir(ctlr, phyaddr, 0x01);
			if((miir(ctlr, phyaddr, 0) & 0x1000) && !(bmsr & 0x0020)){
				miiw(ctlr, phyaddr, 0x1A, 0x2010);
				x = miir(ctlr, phyaddr, 0);
				miiw(ctlr, phyaddr, 0, 0x0200|x);
				for(i = 0; i < 3000; i++){
					delay(1);
					if(miir(ctlr, phyaddr, 0x01) & 0x0020)
						break;
				}
				miiw(ctlr, phyaddr, 0x1A, 0x2000);
					
				anar = miir(ctlr, phyaddr, 0x04);
				anlpar = miir(ctlr, phyaddr, 0x05) & 0x03E0;
				anar &= anlpar;
				bmcr = 0;
				if(anar & 0x380)
					bmcr = 0x2000;
				if(anar & 0x0140)
					bmcr |= 0x0100;
			}
			break;
		}

		/*
		 * Force speed and duplex if no auto-negotiation.
		 */
		if(anlpar == 0){
			medium = -1;
			for(i = 0; i < ether->nopt; i++){
				for(k = 0; k < nelem(mediatable); k++){
					if(cistrcmp(mediatable[k], ether->opt[i]))
						continue;
					medium = k;
					break;
				}
		
				switch(medium){
				default:
					break;

				case 0x00:			/* 10BASE-T */
				case 0x01:			/* 10BASE-2 */
				case 0x02:			/* 10BASE-5 */
					bmcr &= ~(0x2000|0x0100);
					ctlr->configdata[19] &= ~0x40;
					break;

				case 0x03:			/* 100BASE-TX */
				case 0x06:			/* 100BASE-T4 */
				case 0x07:			/* 100BASE-FX */
					ctlr->configdata[19] &= ~0x40;
					bmcr |= 0x2000;
					break;

				case 0x04:			/* 10BASE-TFD */
					bmcr = (bmcr & ~0x2000)|0x0100;
					ctlr->configdata[19] |= 0x40;
					break;

				case 0x05:			/* 100BASE-TXFD */
				case 0x08:			/* 100BASE-FXFD */
					bmcr |= 0x2000|0x0100;
					ctlr->configdata[19] |= 0x40;
					break;
				}
			}
			if(medium != -1)
				miiw(ctlr, phyaddr, 0x00, bmcr);
		}

		if(bmcr & 0x2000)
			ether->mbps = 100;

		ctlr->configdata[8] = 1;
		ctlr->configdata[15] &= ~0x80;
	}
	else{
		ctlr->configdata[8] = 0;
		ctlr->configdata[15] |= 0x80;
	}

	/*
	 * Workaround for some broken HUB chips when connected at 10Mb/s
	 * half-duplex.
	 * This is a band-aid, but as there's no dynamic auto-negotiation
	 * code at the moment, only deactivate the workaround code in txstart
	 * if the link is 100Mb/s.
	 */
	if(ether->mbps != 10)
		ctlr->nop = 0;

	/*
	 * Load the chip configuration and start it off.
	 */
#ifndef FS
	if(ether->oq == 0)
		ether->oq = qopen(256*1024, Qmsg, 0, 0);
#endif
	configure(ether, 0);
	command(ctlr, CUstart, PADDR(&ctlr->cbr->status));

	/*
	 * 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 with the Individual Address Setup command.
	 */
	memset(ea, 0, Eaddrlen);
	if(memcmp(ea, ether->ea, Eaddrlen) == 0){
		for(i = 0; i < Eaddrlen/2; i++){
			x = ctlr->eeprom[i];
			ether->ea[2*i] = x;
			ether->ea[2*i+1] = x>>8;
		}
	}

	ilock(&ctlr->cblock);
	ctlr->action = CbIAS;
	txstart(ether);
	iunlock(&ctlr->cblock);

	/*
	 * 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->shutdown = shutdown;
	ether->multicast = multicast;
#endif
	return 0;
}

#ifndef FS
void
ether82557bothlink(void)
{
	addethercard("i82557",  etheri82557reset);
}
#endif