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Darwin 0.2 Driver Kit

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\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\f0\b0\i0\ul0\fs24 			enet Pseudocode\
		\

\f1\b\fs28 /* \
 * instance variables\
 */
\f0\b0\fs24 \
\{\
	enetBuf_t 	*
\fc0 TxBufList;	// Free buffers. Maybe one global \
					//   list?\
	enetBuf_t 	*RxBufList;\
	id		txBufLock;	// NXSpinLock; protects TxBufList\
	id		rxBufLock;\
	id		rpcLock;	// NXSleepLock; I/O thread and netOutput\
					//   must grab this to do kernel RPCs\
	int		numTxBufsQd;	// # of TX DMA buffers enqueued\
	int 		numRxBufsQd;\
	port_t		IOPort;		// I/O thread gets all of its work \
					//   thru here\
	int 		jamRetryCount;
\
\}\
\

\f1\b\fs28 /* \
 * Exported Methods	\
 */
\f0\b0\fs24 \

\
+ probe:(dev_num_t)devNumber deviceMaster:(port_t)deviceMaster\
\{\
	alloc an instance of self;\
	return [newInst enetInit:devNumber deviceMaster:deviceMaster];\
\}\
\
/*\
 * I think this is only called once...\
 */\
- (int)netInit\
\{\
	init instance variables;\
	init hardware to a good state;\
	for(some initial # of free enetBufs) \{\
		kalloc or vm_allocate a page;\
		break up page into enetBuf's;\
		for each enetBuf_t \{\
			init it;\
			enqueue on Rx or TXBufList;\
			numFreeBufs++;\
		\}\
	\}\
	[self enqueueRxBufs];\
\}\
\
- (int)netOutput : (netbuf_t)buf\
		   addrs : (void *)addrs\
\{\
	/*\
	 * Assuming that this is NOT called at interrupt level...\
	 */\
	[rpcLock lock];\
	dma_enqueue(data = nb_map(netbuf), \
		dma_id = netbuf, \
		length = nb_size(netbuf));\
	if(!running) \{\
		[self dmaStart];\
		arrange for NetJamTimer() callout in 10 seconds;\
	\}\
	[rpcLock unlock];\
\}\
		   \
- (netbuf_t)netGetBuf\
\{\
	if no bufs in TxBufList \{\
		return NULL;\
	\}\
	return(nb_alloc_wrapper(&enetBuf->dmaData,\
		size of DMA Data,\
		&enetBufFree(),\
		&enetBuf));\
\}\
\
- (int)netControl : (const char *)command\
		    data : (void *)data\
\{\
	/* crufty crap */\
\}\
\

\f1\b\fs28 /* \
 * Private Methods\
 */
\f0\b0\fs24 \
- (void)enqueueRxBufs\
\{\
	/*\
	 * Enqueue all free bufs in RxBufList on hardware DMA queue\
	 */\
	[rpcLock lock];\
	do \{\
		get an enetBuf from RxBufList;\
		netbuf = nb_alloc_wrapper(&enetBuf->dmaData,\
			size of DMA Data,\
			&enetBufFree(),\
			&enetBuf);\
		dma_enqueue(data = &enetBuf.dmaData,\
			dma_id = netbuf, \
			length = sizeof DMA data);\
		rxDmaQCount++;\
	\
	\} while RxBufList not empty;\
	[rpcLock unlock]; \
\}\
\
- enetInit:(dev_num_t)devNumber deviceMaster:(port_t)deviceMaster\
\{\
	get ethernet address from monitor or somewhere;\
	if_attach(a zillion args);\
	return self;\
\}\
\
- enetInt\
\{\
	if device interrupt \{\
		log this bogality;\
	\}\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 	if chan[rcv] interrupt \{\
		[self enetRxInt];\
	\}\
	if chan[xmit] interrupt \{\
		[self enetTxInt];\
	\}\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \}\
\
/*\
 * Note should not be any device errors, only channel errors.\
 */\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 - enetRxInt\
\{\
	if any DMA errors (errorInterrupt, busError) \{\
		dmaAort;\
		log it and clear it;\
	\}\
	if overrun \{\
		log it and clear it;\
	\}\
	do \{\
		[rpcLock lock];\
		chan_dma_dequeue(completed only, enable interrupts \
				if no more);\
		[rpcLock unlock];\
		if(dma_id == NULL)\
			break - done;\
		if(any errors in chan_status) \{\
			/* drop it on the floor */\
			nb_free((netbuf_t)dma_id);\
		\}\
		else \{\
			filter out unwanted multicast packets;\
			if_handle_input((netbuf_t)dma_id);\
		\}\
	\} for all completed descriptors;\
	[self enqueueRxBufs];\
\}\
\
- enetTxInt\
\{\
	abort = 0;\
	\
	untimeout(NetJamTimer callout);\
	if any DMA errors (errorInterrupt, busError) \{\
		log it and clear it;\
		dmaDisable;\
		abort++;\
	\}\
	if late collision or underrun \{\
		log it and clear it;\
		abort++;\
	\}\
	if No heart beat or >15 retries error \{\
		abort++;\
		[self enJam];\
	\}\
	do \{\
		[rpcLock lock];\
		if(abort) \{\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 			chan_dma_dequeue(ALL descriptors, enable ints);\
		\}\
		else \{
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 \
			chan_dma_dequeue(
\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 completed only, enable
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0  
\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 interrupts 
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 \
				
\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 if no more
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 );\
		\}\
		[rpcLock unlock];\
		if(dma_id == NULL)\
			break - done;\
		nb_free((netbuf_t)dma_id);\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 	\} for all completed descriptors;
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 \
\}\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \
- (jam_t)enJam\
\{\
\
   	if (++jamRetryCount < max) \
		return JAM_GOOD;\
\
	remember current I/F mode (TPE or thin);\
	select TPE;\
	wait some h/w delay for Link Integrity to settle down;\
	if link integrity good \{\
		return JAM_GOOD;\
	\}\
	else if (mode was TPE on entry) \{\
		select Thin wire;\
		return JAM_GOOD;\
	\}\
	\
	/* \
	 * Net down.\
	 */\
	dequeue and free all frames;\
	set net_down flag; set timeout to clear it in 10 seconds;\
	if_down();\
	return JAM_BAD;\
\}\
\
- (enetBuf_t)enetBufGet(which queue)\
\{\
	safely get an enetBuf from appropriate queue;\
\}\
\
- (void)enetBufPut\
\{\
	safely put an enetBuf on its free queue;\
\}\
\

\f1\b\fs28 /*\
 * Threads and Functions\
 */
\f0\b0\fs24 \
\
/*\
 * enetThread() does the following:\
 * -- handles all interrupts (normally DMA; others are errors)\
 * -- Dispatches received packets; keeps RX DMA queue as full as possible\
 * -- detects Net Jammed conditions, reconfigures I/F (TPE or Thin).\
 */\
enetThread(id enetObj)\
\{\
	msg_receive(IOPort);\
	switch msg_id \{\
	    case INT_MSG_DEVICE:\
	    case INT_MSG_DMA:\
	    	[enetObj enetInt];\
	    case ENET_JAMMED_MSG_ID:\
	   	[enetObj enJam];\
	\}\
\}\
\
/*\
 * Called out from nb_free(), as freefunc(freefunc_arg).\
 */\
enetBufFree(enetBuf_t *enetBuf) \{\
  	enqueue this on enetBufList;\
\}\
\
/*\
 * Called out via IOTimeout(); we arrange for one of these to happen 10\
 * seconds after we start a DMA out. This handles the "net jammed so bad that\
 * we don't even see collisions" error, caused by continuous carrier sense.\
 */\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 NetJamTimer
\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 (
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 port_t enetIOPort
\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 )
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0  \{\
	send ENET_JAMMED_MSG message to the I/O thread;\
\}\

}

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