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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 		current m68k Etehernet driver notes\
		\

\f1\b\fs28 Globals
\f0\b0\fs24 \
		\
struct en_softc en_softc[] - one per interface.\
\

\f1\b\fs28 Functions
\f0\b0\fs24 \
\
int enprobe(caddr_t reg, int ctrl) \
// 
\f1\b\fs28 called from
\f0\b0\fs24 : \
//	via autoconf, in endriver\
\{\
	return "real" address 
\fc0 (w/slot_id_map offset) 
of en registers;\
\}\
\
int enattach(
struct bus_device *bd
) \

// 
\f1\b\fs28 called from
\f0\b0\fs24 : via autoconf, in endriver\

\{\
	get enet address saved by ROM in global etheraddr, save it in \
		en_softc and write to hardware;\
	if_attach(
eninit, NULL, enoutput, engetbuf, encontrol,
 a slew of args);\
\}\
\
int eninit(netif_t netif)\
// 
\f1\b\fs28 called from
\f0\b0\fs24 :\
//	en_setaddr\
/	enattach\
/	encontrol\
\{\
	get *en_softc from netif;\
	basic "get s/w and h/w state to known condition" stuff;\
	set new phys address if spec'd in en_softc.is_flags;\
	queue up 
NTXBUFS
 DMA buffers ib en_softc.
is_tx_free
;\
	queue up 
NRXBUFS
 DMA buffers in hardware queue;\
\}\
\
int 
en_rx_grabbufs(struct en_softc *is)\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 // 
\f1\b\fs28 called from
\f0\b0\fs24 :\
/	timeout() callout from in 
\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 en_rx_dmaintr
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 ()
\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \{\
	get memory via if_busalloc for all DMA headers in is_rx_free,\
		enqueue result in hardware queue;\
\}\
\
void en_rx_dmaintr(int unit)\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 // 
\f1\b\fs28 called from
\f0\b0\fs24 :\
/	DMA interrupt handler\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \{\
	if any DMA errors\
		log to console (but keep going...!);\
	get length of packet from DMA engine;\
	if invalid length \{\
		log error;\
		if_errors_set();\
		re-enqueue this header and buffer on h/w;\
	\}\
	nb = if_rbusget(dma buffer, HDR_SIZE + length);\
	if_handle_input(en_softc->is_if, nb, NULL);\
	if_busalloc() a new DMA buffer;\
	if none available\
		put this header on is_rx_free\
	else\
		enqueue this header and buffer on h/w;\
	record is_last_rx timestamp;\
\}\
\
int enoutput(netif_t netif,\
	 netbuf_t nb,\
	 void *dst)\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 // 
\f1\b\fs28 called from
\f0\b0\fs24 :\
//	higher layer protocol - registered in if_attach() in enattach().\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \{\
	/*\
	 * Crufty crap:\
	 * \
	 *   struct ifnet *ifp = (struct ifnet *)netif; \
	 *   struct mbuf *m = (struct mbuf *)nb; \
	 *\
	 * Find out from Brad or jks why the "XXX" one these lines and what \
	 * we hope to do about this kind of thing in the future...\
	 */\
	 \

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 	get *en_softc from netif;\
	if not running or net down \{\
		nb_free(nb);\
		return ENETDOWN;\
	\}\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 	copy dest addr from dst to mtod(m, struct ether_header *);\
	copy source addr from en_softc to mtod(m, struct ether_header *);\
	if (IF_QFULL(&ifp->if_snd)) \{\
		handle queue full error;\
		return ENOBUFS;\
	\}\
	IF_ENQUEUE(&ifp->if_snd, m);\
	if not active\
		enstart();\
	return 0;\
\}\
\
int enstart(dev_t dev)\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 // 
\f1\b\fs28 called from
\f0\b0\fs24 :\
/	
\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 en_tx_dmaintr
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 (),
\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0  enoutput
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 ()
\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \{\
	dequeue an mbuf from our netif;\
	get a free DMA header from is_tx_free;\
	if none \{\
		log error;\
		nb_free(nb);\
		return;\
	\}\
	if_busalloc(free hdr, netbuf);\
	calculate DMA start/end registers kludges;\
	splimp();\
	start en_jam timeout timer;\
	dma_enqueue() the header (in h/w if necessary);\
	set output_active flag;\
	splx();\
\}\
\
int en_down(int unit)\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 // 
\f1\b\fs28 called from
\f0\b0\fs24 :\
//	boot (to take net down)\
//	en_jam(), on "I give up, it's broken"\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \{\
	if_down();\
\}\
\
int en_antijam(struct en_softc *is)\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 // 
\f1\b\fs28 called from
\f0\b0\fs24 :\
//	en_jam, timeout() callout after "I give up"\
//	untimeout()'d in encontrol(
\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 IFCONTROL_SETFLAGS
\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 );\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \{\
	clear jammed flag;\
	huh???\
\}\
\
int en_jam(struct en_softc *is)\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 // 
\f1\b\fs28 called from
\f0\b0\fs24 :\
//	timeout() callout from enstart();\

\fc0 //	tx_intr, on "no heartbeat detect"
\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \{\
	if thin wire mode \{\
		if heartbeat on TPE \{\
			select TPE;\
			return OK;\
		\}\
	\}\
	else \{\
		if heartbeat\
			return OK (Huh???)\
	\}\
	log error message;\
	en_down();\
	enable en_antijam() timeout;\
	return error;\
\}	\
\
void en_tx_dmaintr(int unit)\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 // 
\f1\b\fs28 called from
\f0\b0\fs24 :\
//	DMA interrupt handler\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \{\
	disable en_jam timeout;\
	while(dhp = dma_dequeue()) \{\
		if any DMA channel errors \{\
			dma_enqueue() this dhp;\
			return;\
		\}\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520\fc0 		if > 16 collision error \{\
			if_oerrors_set();\
			if jam_count exceeded and not currently jammed \{\
				if(en_jam())\
					goto out;\
			\}\
			dma_enqueue this dhp as a retry;\
			return;\
		\}\
		if TPE \{\
			if en_rx timeout exceeded \{\
				/* huh??? this is tx... */\
				if(en_jam()) \{\
					dma_enqueue this hdr;\
					return;\
				\}\
			\}\
		\}\
out:\
		if_busfree(dhp);\
		enqueue this dhp on is_tx_free;\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 	\}\
	\
	return;\
\}\
\
int encontrol(netif_t netif,\
	  const char *command,\
	  void *data)\

\pard\tx1140\tx2300\tx3440\tx4600\tx5760\tx6900\tx8060\tx9200\tx10360\tx11520 // 
\f1\b\fs28 called from
\f0\b0\fs24 :\
//	higher level protocol, registered in if_attaach()\

\pard\tx1152\tx2304\tx3456\tx4608\tx5760\tx6912\tx8064\tx9216\tx10368\tx11520\fc0 \{\
	misc crufty stuff;\
\}\
\
\

\f1\b\fs28 Notes
\f0\b0\fs24 \
\
1. We should probably NOT use ifnet, ONLY netif_t. Get ptr to local \
   data (or an id) from the "void *if_private(netif_t netif)" \
   function in netif.\
\
2. headers, buffers, and stuff\
\
   struct mbuf \{\
   	struct	mbuf *m_next;		/* next buffer in chain */\
	u_long	m_off;			/* offset of data */\
	short	m_len;			/* amount of data in this mbuf */\
	short	m_type;			/* mbuf type (0 == free) */\
	union \{\
		u_char	mun_dat[MLEN];	/* data storage */\
		struct \{\
			short	mun_cltype;	/* "cluster" type */\
			int	(*mun_clfun)();\
			int	mun_clarg;\
			int	(*mun_clswp)();\
		\} mun_cl;\
	\} m_un;\
	struct	mbuf *m_act;		/* link in higher-level mbuf list */\
   \};\
\
   struct dma_hdr \{\
	struct dma_hdr *volatile dh_link;/* pts to next dma_hdr in chain */\
	char *dh_start;			/* pts to start of buffer for dma */\
	char *dh_stop;			/* pts to end of buffer + 1 for dma */\
	volatile int dh_flags;		/* see below */\
	volatile int dh_state;		/* csr at time of dma interrupt */\
	char *volatile dh_next;		/* next at time of dma interrupt */\
	int dh_drvarg;			/* for use by driver */\
   \};\
   \
   struct ether_header \{\
	u_char	 ether_dhost[6];\
	u_char	 ether_shost[6];\
	u_short ether_type;\
   \};\
\
   actual ethernet packet \{\
   	/* \
	 * physically contiguous memory.\
	 * On TX, \
	 */\
   	struct ether_header hdr;\
	some data;\
   \}\
   \
   struct enbuf \{\
	union  \{\
		struct enbuf 	*Uenb_next;\
		char 		Uenb_data[BUF_SIZE];\
	\} Uenbuf;\
   \};\
   \
   enoutput():\
   \
   	Currently, it's actually passed an mbuf, although this is declared\
   	as a netbuf_t (opaque).\
   \
   	&ether_header = mbuf->m_off.\
	\
   enstart():\
   	This is a total hack. We get an mbuf via IF_DEQUEUE, which should\
	not be visible to us. Then we cast the mbuf to a netbuf_t. We get\
	the size of the mbuf via nb_size() (which is legal). Then we cast\
	a DMA header (which we get from is_tx_free) to a en_dma_buf_t and\
	pass it to if_busalloc().\

}

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