etherelnk3.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。

	 * Free any completed packets.
	 */
	pd = ctlr->dntail;
	while(ctlr->dnq){
		if(PADDR(&pd->np) == inl(port+DnListPtr))
			break;
		ctlr->dnq--;
		pd = pd->next;
	}
	ctlr->dntail = pd;

	stalled = 0;
	while(ctlr->dnq < (ctlr->ndn-1)){
		tb = &ether->tb[ether->ti];
		if(tb->owner != Interface)
			break;

		pd = ctlr->dnhead->next;
		pd->np = 0;
		pd->control = dnIndicate|tb->len;
		memmove(pd->vaddr, tb->pkt, tb->len);
		pd->len = updnLastFrag|tb->len;

		tb->owner = Host;
		ether->ti = NEXT(ether->ti, ether->ntb);

		if(stalled == 0 && ctlr->dnq && inl(port+DnListPtr)){
			COMMAND(port, Stall, dnStall);
			for(timeo = 100; (STATUS(port) & commandInProgress) && timeo; timeo--)
				;
			if(timeo == 0)
				print("#l%d: dnstall %d\n", ether->ctlrno, timeo);
			stalled = 1;
		}

		ctlr->dnhead->np = PADDR(&pd->np);
		ctlr->dnhead->control &= ~dnIndicate;
		ctlr->dnhead = pd;
		if(ctlr->dnq == 0)
			ctlr->dntail = pd;
		ctlr->dnq++;
	}

	/*
	 * If the adapter is not currently processing anything
	 * and there is something on the queue, start it processing.
	 */
	if(inl(port+DnListPtr) == 0 && ctlr->dnq)
		outl(port+DnListPtr, PADDR(&ctlr->dnhead->np));
	if(stalled)
		COMMAND(port, Stall, dnUnStall);
}

static void
transmit(Ether* ether)
{
	Ctlr *ctlr;
	int port, w;

	port = ether->port;
	ctlr = ether->ctlr;

	ilock(&ctlr->wlock);
	if(ctlr->busmaster == 2)
		txstart905(ether);
	else{
		w = (STATUS(port)>>13) & 0x07;
		COMMAND(port, SelectRegisterWindow, Wop);
		txstart(ether);
		COMMAND(port, SelectRegisterWindow, w);
	}
	iunlock(&ctlr->wlock);
}

static void
receive905(Ether* ether)
{
	Ctlr *ctlr;
	int len, port;
	Pd *pd;
	RingBuf *rb;

	ctlr = ether->ctlr;
	port = ether->port;

	for(pd = ctlr->uphead; pd->control & upPktComplete; pd = pd->next){
		if(!(pd->control & upError)){
			rb = &ether->rb[ether->ri];
			if(rb->owner == Interface){
				len = pd->control & rxBytes;
				rb->len = len;
				memmove(rb->pkt, pd->vaddr, len);

				rb->owner = Host;
				ether->ri = NEXT(ether->ri, ether->nrb);
			}
		}

		pd->control = 0;
		COMMAND(port, Stall, upUnStall);
	}
	ctlr->uphead = pd;
}

static void
receive(Ether* ether)
{
	int len, port, rxstatus;
	RingBuf *rb;

	port = ether->port;

	if(debug) print("receive...");
	while(((rxstatus = ins(port+RxStatus)) & rxIncomplete) == 0){
		/*
		 * If there was an error, throw it away and continue.
		 * The 3C5[078]9 has the error info in the status register
		 * and the 3C59[0257] implement a separate RxError register.
		 */
		if((rxstatus & rxError) == 0){
			/*
			 * Packet received. Read it into the next free
			 * ring buffer, if any. Must read len bytes padded
			 * to a doubleword, can be picked out 32-bits at
			 * a time. The CRC is already stripped off.
			 */
			rb = &ether->rb[ether->ri];
			if(rb->owner == Interface){
				len = (rxstatus & rxBytes9);
				rb->len = len;
				insl(port+Fifo, rb->pkt, HOWMANY(len, 4));

				rb->owner = Host;
				ether->ri = NEXT(ether->ri, ether->nrb);
			}else
if(debug) print("toss...");
		}
else
if(debug) print("error...");

		/*
		 * All done, discard the packet.
		 */
		COMMAND(port, RxDiscard, 0);
		while(STATUS(port) & commandInProgress)
			;
	}
}

static void
statistics(Ether* ether)
{
	Ctlr *ctlr;
	int i, port, w;

	ctlr = ether->ctlr;
	port = ether->port;

	/*
	 * 3C59[27] require a read between a PIO write and
	 * reading a statistics register.
	 */
	w = (STATUS(port)>>13) & 0x07;
	COMMAND(port, SelectRegisterWindow, Wstatistics);
	STATUS(port);

	for(i = 0; i < 0x0A; i++)
		inb(port+i);
	ins(port+BytesRcvdOk);
	ins(port+BytesXmittedOk);

	switch(ctlr->xcvr){

	case xcvrMii:
	case xcvr100BaseTX:
	case xcvr100BaseFX:
		COMMAND(port, SelectRegisterWindow, Wdiagnostic);
		STATUS(port);
		inb(port+BadSSD);
		break;
	}

	COMMAND(port, SelectRegisterWindow, w);
}

static void
interrupt(Ureg*, void* arg)
{
	Ether *ether;
	int port, status, s, w, x;
	Ctlr *ctlr;

	ether = arg;
	port = ether->port;
	ctlr = ether->ctlr;

	w = (STATUS(port)>>13) & 0x07;
	COMMAND(port, SelectRegisterWindow, Wop);

	while((status = STATUS(port)) & (interruptMask|interruptLatch)){
		if(status & hostError){
			/*
			 * Adapter failure, try to find out why, reset if
			 * necessary. What happens if Tx is active and a reset
			 * occurs, need to retransmit? This probably isn't right.
			 */
			COMMAND(port, SelectRegisterWindow, Wdiagnostic);
			x = ins(port+FifoDiagnostic);
			COMMAND(port, SelectRegisterWindow, Wop);
			print("elnk3#%d: status 0x%uX, diag 0x%uX\n",
			    ether->ctlrno, status, x);

			if(x & txOverrun){
				if(ctlr->busmaster == 0)
					COMMAND(port, TxReset, 0);
				else
					COMMAND(port, TxReset, (updnReset|dmaReset));
				COMMAND(port, TxEnable, 0);
			}

			if(x & rxUnderrun){
				/*
				 * This shouldn't happen...
				 * Reset the receiver and restore the filter and RxEarly
				 * threshold before re-enabling.
				 * Need to restart any busmastering?
				 */
				COMMAND(port, SelectRegisterWindow, Wstate);
				s = (port+RxFilter) & 0x000F;
				COMMAND(port, SelectRegisterWindow, Wop);
				COMMAND(port, RxReset, 0);
				while(STATUS(port) & commandInProgress)
					;
				COMMAND(port, SetRxFilter, s);
				COMMAND(port, SetRxEarlyThresh, ctlr->rxearly>>ctlr->ts);
				COMMAND(port, RxEnable, 0);
			}

			status &= ~hostError;
		}

		if(status & (transferInt|rxComplete)){
			receive(ether);
			status &= ~(transferInt|rxComplete);
		}

		if(status & (upComplete)){
			COMMAND(port, AcknowledgeInterrupt, upComplete);
			receive905(ether);
			status &= ~upComplete;
		}

		if(status & txComplete){
			/*
			 * Pop the TxStatus stack, accumulating errors.
			 * Adjust the TX start threshold if there was an underrun.
			 * If there was a Jabber or Underrun error, reset
			 * the transmitter, taking care not to reset the dma logic
			 * as a busmaster receive may be in progress.
			 * For all conditions enable the transmitter.
			 */
			s = 0;
			do{
				if(x = inb(port+TxStatus))
					outb(port+TxStatus, 0);
				s |= x;
			}while(STATUS(port) & txComplete);

			if(s & txUnderrun){
				if(ctlr->busmaster == 2){
					while(inl(port+PktStatus) & dnInProg)
						;
				}
				COMMAND(port, SelectRegisterWindow, Wdiagnostic);
				while(ins(port+MediaStatus) & txInProg)
					;
				COMMAND(port, SelectRegisterWindow, Wop);
				if(ctlr->txthreshold < ETHERMAXTU)
					ctlr->txthreshold += ETHERMINTU;
			}

			/*
			 * According to the manual, maxCollisions does not require
			 * a TxReset, merely a TxEnable. However, evidence points to
			 * it being necessary on the 3C905. The jury is still out.
			 * On busy or badly configured networks maxCollisions can
			 * happen frequently enough for messages to be annoying so
			 * keep quiet about them by popular request.
			 */
			if(s & (txJabber|txUnderrun|maxCollisions)){
				if(ctlr->busmaster == 0)
					COMMAND(port, TxReset, 0);
				else
					COMMAND(port, TxReset, (updnReset|dmaReset));
				while(STATUS(port) & commandInProgress)
					;
				COMMAND(port, SetTxStartThresh, ctlr->txthreshold>>ctlr->ts);
				if(ctlr->busmaster == 2){
					outl(port+TxFreeThresh, HOWMANY(ETHERMAXTU, 256));
					status |= dnComplete;
				}
			}

			if(s & ~(txStatusComplete|maxCollisions))
				print("#l%d: txstatus 0x%uX, threshold %d\n",
			    		ether->ctlrno, s, ctlr->txthreshold);
			COMMAND(port, TxEnable, 0);
			status &= ~txComplete;
			status |= txAvailable;
		}

		if(status & txAvailable){
			COMMAND(port, AcknowledgeInterrupt, txAvailable);
			txstart(ether);
			status &= ~txAvailable;
		}

		if(status & dnComplete){
			COMMAND(port, AcknowledgeInterrupt, dnComplete);
			txstart905(ether);
			status &= ~dnComplete;
		}

		if(status & updateStats){
			statistics(ether);
			status &= ~updateStats;
		}

		/*
		 * Currently, this shouldn't happen.
		 */
		if(status & rxEarly){
			COMMAND(port, AcknowledgeInterrupt, rxEarly);
			status &= ~rxEarly;
		}

		/*
		 * Panic if there are any interrupts not dealt with.
		 */
		if(status & interruptMask)
			panic("elnk3#%d: interrupt mask 0x%uX\n", ether->ctlrno, status);

		COMMAND(port, AcknowledgeInterrupt, interruptLatch);
	}

	COMMAND(port, SelectRegisterWindow, w);
}

static void
txrxreset(int port)
{
	COMMAND(port, TxReset, 0);
	while(STATUS(port) & commandInProgress)
		;
	COMMAND(port, RxReset, 0);
	while(STATUS(port) & commandInProgress)
		;
}

static void
detach(Ether* ether)
{
	txrxreset(ether->port);
}

typedef struct Adapter {
	int	port;
	int	irq;
	int	tbdf;
} Adapter;
static Block* adapter;

static void
tcmadapter(int port, int irq, int tbdf)
{
	Block *bp;
	Adapter *ap;

	bp = allocb(sizeof(Adapter));
	ap = (Adapter*)bp->rp;
	ap->port = port;
	ap->irq = irq;
	ap->tbdf = tbdf;

	bp->next = adapter;
	adapter = bp;
}

/*
 * Write two 0 bytes to identify the IDport and then reset the
 * ID sequence. Then send the ID sequence to the card to get
 * the card into command state.
 */
static void
idseq(void)
{
	int i;
	uchar al;
	static int reset, untag;

	/*
	 * One time only:
	 *	reset any adapters listening
	 */
	if(reset == 0){
		outb(IDport, 0);
		outb(IDport, 0);
		outb(IDport, 0xC0);
		delay(20);
		reset = 1;
	}

	outb(IDport, 0);
	outb(IDport, 0);
	for(al = 0xFF, i = 0; i < 255; i++){
		outb(IDport, al);
		if(al & 0x80){
			al <<= 1;
			al ^= 0xCF;
		}
		else
			al <<= 1;
	}

	/*
	 * One time only:
	 *	write ID sequence to get the attention of all adapters;
	 *	untag all adapters.
	 * If we do a global reset here on all adapters we'll confuse any
	 * ISA cards configured for EISA mode.
	 */
	if(untag == 0){
		outb(IDport, 0xD0);
		untag = 1;
	}
}

static ulong
activate(void)
{
	int i;
	ushort x, acr;

	/*
	 * Do the little configuration dance:
	 *
	 * 2. write the ID sequence to get to command state.
	 */
	idseq();

	/*
	 * 3. Read the Manufacturer ID from the EEPROM.
	 *    This is done by writing the IDPort with 0x87 (0x80
	 *    is the 'read EEPROM' command, 0x07 is the offset of
	 *    the Manufacturer ID field in the EEPROM).
	 *    The data comes back 1 bit at a time.
	 *    We seem to need a delay here between reading the bits.
	 *
	 * If the ID doesn't match, there are no more adapters.
	 */
	outb(IDport, 0x87);
	delay(20);
	for(x = 0, i = 0; i < 16; i++){
		delay(20);
		x <<= 1;
		x |= inb(IDport) & 0x01;
	}
	if(x != 0x6D50)
		return 0;

	/*
	 * 3. Read the Address Configuration from the EEPROM.
	 *    The Address Configuration field is at offset 0x08 in the EEPROM).
	 */
	outb(IDport, 0x88);
	for(acr = 0, i = 0; i < 16; i++){
		delay(20);
		acr <<= 1;
		acr |= inb(IDport) & 0x01;
	}

	return (acr & 0x1F)*0x10 + 0x200;
}

static void
tcm509isa(void)
{
	int irq, port;

	/*
	 * Attempt to activate all adapters. If adapter is set for
	 * EISA mode (0x3F0), tag it and ignore. Otherwise, activate
	 * it fully.
	 */
	while(port = activate()){
		/*
		 * 6. Tag the adapter so it won't respond in future.
		 */
		outb(IDport, 0xD1);
		if(port == 0x3F0)
			continue;

		/*
		 * 6. Activate the adapter by writing the Activate command
		 *    (0xFF).
		 */
		outb(IDport, 0xFF);
		delay(20);

		/*
		 * 8. Can now talk to the adapter's I/O base addresses.
		 *    Use the I/O base address from the acr just read.
		 *
		 *    Enable the adapter and clear out any lingering status
		 *    and interrupts.
		 */
		while(STATUS(port) & commandInProgress)
			;
		COMMAND(port, SelectRegisterWindow, Wsetup);
		outs(port+ConfigControl, Ena);

		txrxreset(port);
		COMMAND(port, AcknowledgeInterrupt, 0xFF);

		irq = (ins(port+ResourceConfig)>>12) & 0x0F;