xref: /minix3/sys/arch/i386/stand/lib/netif/dp8390.c (revision 58a2b0008e28f606a7f7f5faaeaba4faac57a1ea)
1*58a2b000SEvgeniy Ivanov /*	$NetBSD: dp8390.c,v 1.6 2008/12/14 18:46:33 christos Exp $	*/
2*58a2b000SEvgeniy Ivanov 
3*58a2b000SEvgeniy Ivanov /*
4*58a2b000SEvgeniy Ivanov  * Polling driver for National Semiconductor DS8390/WD83C690 based
5*58a2b000SEvgeniy Ivanov  * ethernet adapters.
6*58a2b000SEvgeniy Ivanov  *
7*58a2b000SEvgeniy Ivanov  * Copyright (c) 1998 Matthias Drochner.  All rights reserved.
8*58a2b000SEvgeniy Ivanov  *
9*58a2b000SEvgeniy Ivanov  * Copyright (c) 1994, 1995 Charles M. Hannum.  All rights reserved.
10*58a2b000SEvgeniy Ivanov  *
11*58a2b000SEvgeniy Ivanov  * Copyright (C) 1993, David Greenman.  This software may be used, modified,
12*58a2b000SEvgeniy Ivanov  * copied, distributed, and sold, in both source and binary form provided that
13*58a2b000SEvgeniy Ivanov  * the above copyright and these terms are retained.  Under no circumstances is
14*58a2b000SEvgeniy Ivanov  * the author responsible for the proper functioning of this software, nor does
15*58a2b000SEvgeniy Ivanov  * the author assume any responsibility for damages incurred with its use.
16*58a2b000SEvgeniy Ivanov  */
17*58a2b000SEvgeniy Ivanov 
18*58a2b000SEvgeniy Ivanov #include <sys/types.h>
19*58a2b000SEvgeniy Ivanov #include <machine/pio.h>
20*58a2b000SEvgeniy Ivanov 
21*58a2b000SEvgeniy Ivanov #include <lib/libsa/stand.h>
22*58a2b000SEvgeniy Ivanov #include <libi386.h>
23*58a2b000SEvgeniy Ivanov 
24*58a2b000SEvgeniy Ivanov #include <dev/ic/dp8390reg.h>
25*58a2b000SEvgeniy Ivanov #include "dp8390.h"
26*58a2b000SEvgeniy Ivanov #ifdef SUPPORT_NE2000
27*58a2b000SEvgeniy Ivanov #include "ne.h"
28*58a2b000SEvgeniy Ivanov #endif
29*58a2b000SEvgeniy Ivanov 
30*58a2b000SEvgeniy Ivanov #include "etherdrv.h"
31*58a2b000SEvgeniy Ivanov 
32*58a2b000SEvgeniy Ivanov int dp8390_iobase, dp8390_membase, dp8390_memsize;
33*58a2b000SEvgeniy Ivanov #if defined(SUPPORT_WD80X3) && defined(SUPPORT_SMC_ULTRA)
34*58a2b000SEvgeniy Ivanov int dp8390_is790;
35*58a2b000SEvgeniy Ivanov #endif
36*58a2b000SEvgeniy Ivanov uint8_t dp8390_cr_proto;
37*58a2b000SEvgeniy Ivanov uint8_t dp8390_dcr_reg;
38*58a2b000SEvgeniy Ivanov 
39*58a2b000SEvgeniy Ivanov #define WE_IOBASE dp8390_iobase
40*58a2b000SEvgeniy Ivanov 
41*58a2b000SEvgeniy Ivanov static u_short rec_page_start;
42*58a2b000SEvgeniy Ivanov static u_short rec_page_stop;
43*58a2b000SEvgeniy Ivanov static u_short next_packet;
44*58a2b000SEvgeniy Ivanov 
45*58a2b000SEvgeniy Ivanov extern u_char eth_myaddr[6];
46*58a2b000SEvgeniy Ivanov 
47*58a2b000SEvgeniy Ivanov #ifndef _STANDALONE
48*58a2b000SEvgeniy Ivanov static void *vmembase;
49*58a2b000SEvgeniy Ivanov extern void *mapmem(int, int);
50*58a2b000SEvgeniy Ivanov extern void unmapmem(void *, int);
51*58a2b000SEvgeniy Ivanov extern int mapio(void);
52*58a2b000SEvgeniy Ivanov 
53*58a2b000SEvgeniy Ivanov static void
bbcopy(void * src,void * dst,int len)54*58a2b000SEvgeniy Ivanov bbcopy(void *src, void *dst, int len)
55*58a2b000SEvgeniy Ivanov {
56*58a2b000SEvgeniy Ivanov 	char *s = (char *)src;
57*58a2b000SEvgeniy Ivanov 	char *d = (char *)dst;
58*58a2b000SEvgeniy Ivanov 
59*58a2b000SEvgeniy Ivanov 	while (len--)
60*58a2b000SEvgeniy Ivanov 		*d++ = *s++;
61*58a2b000SEvgeniy Ivanov }
62*58a2b000SEvgeniy Ivanov #endif
63*58a2b000SEvgeniy Ivanov 
64*58a2b000SEvgeniy Ivanov static void dp8390_read(int, char *, u_short);
65*58a2b000SEvgeniy Ivanov 
66*58a2b000SEvgeniy Ivanov #define NIC_GET(reg) inb(WE_IOBASE + reg)
67*58a2b000SEvgeniy Ivanov #define NIC_PUT(reg, val) outb(WE_IOBASE + reg, val)
68*58a2b000SEvgeniy Ivanov 
69*58a2b000SEvgeniy Ivanov static void
dp8390_init(void)70*58a2b000SEvgeniy Ivanov dp8390_init(void)
71*58a2b000SEvgeniy Ivanov {
72*58a2b000SEvgeniy Ivanov 	int i;
73*58a2b000SEvgeniy Ivanov 
74*58a2b000SEvgeniy Ivanov 	/*
75*58a2b000SEvgeniy Ivanov 	 * Initialize the NIC in the exact order outlined in the NS manual.
76*58a2b000SEvgeniy Ivanov 	 * This init procedure is "mandatory"...don't change what or when
77*58a2b000SEvgeniy Ivanov 	 * things happen.
78*58a2b000SEvgeniy Ivanov 	 */
79*58a2b000SEvgeniy Ivanov 
80*58a2b000SEvgeniy Ivanov 	/* Set interface for page 0, remote DMA complete, stopped. */
81*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_STP);
82*58a2b000SEvgeniy Ivanov 
83*58a2b000SEvgeniy Ivanov 	if (dp8390_dcr_reg & ED_DCR_LS) {
84*58a2b000SEvgeniy Ivanov 		NIC_PUT(ED_P0_DCR, dp8390_dcr_reg);
85*58a2b000SEvgeniy Ivanov 	} else {
86*58a2b000SEvgeniy Ivanov 		/*
87*58a2b000SEvgeniy Ivanov 		 * Set FIFO threshold to 8, No auto-init Remote DMA, byte
88*58a2b000SEvgeniy Ivanov 		 * order=80x86, byte-wide DMA xfers,
89*58a2b000SEvgeniy Ivanov 		 */
90*58a2b000SEvgeniy Ivanov 		NIC_PUT(ED_P0_DCR, ED_DCR_FT1 | ED_DCR_LS);
91*58a2b000SEvgeniy Ivanov 	}
92*58a2b000SEvgeniy Ivanov 
93*58a2b000SEvgeniy Ivanov 	/* Clear remote byte count registers. */
94*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_RBCR0, 0);
95*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_RBCR1, 0);
96*58a2b000SEvgeniy Ivanov 
97*58a2b000SEvgeniy Ivanov 	/* Tell RCR to do nothing for now. */
98*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_RCR, ED_RCR_MON);
99*58a2b000SEvgeniy Ivanov 
100*58a2b000SEvgeniy Ivanov 	/* Place NIC in internal loopback mode. */
101*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_TCR, ED_TCR_LB0);
102*58a2b000SEvgeniy Ivanov 
103*58a2b000SEvgeniy Ivanov 	/* Set lower bits of byte addressable framing to 0. */
104*58a2b000SEvgeniy Ivanov 	if (dp8390_is790)
105*58a2b000SEvgeniy Ivanov 		NIC_PUT(0x09, 0);
106*58a2b000SEvgeniy Ivanov 
107*58a2b000SEvgeniy Ivanov 	/* Initialize receive buffer ring. */
108*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_BNRY, rec_page_start);
109*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_PSTART, rec_page_start);
110*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_PSTOP, rec_page_stop);
111*58a2b000SEvgeniy Ivanov 
112*58a2b000SEvgeniy Ivanov 	/*
113*58a2b000SEvgeniy Ivanov 	 * Clear all interrupts.  A '1' in each bit position clears the
114*58a2b000SEvgeniy Ivanov 	 * corresponding flag.
115*58a2b000SEvgeniy Ivanov 	 */
116*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_ISR, 0xff);
117*58a2b000SEvgeniy Ivanov 
118*58a2b000SEvgeniy Ivanov 	/*
119*58a2b000SEvgeniy Ivanov 	 * Disable all interrupts.
120*58a2b000SEvgeniy Ivanov 	 */
121*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_IMR, 0);
122*58a2b000SEvgeniy Ivanov 
123*58a2b000SEvgeniy Ivanov 	/* Program command register for page 1. */
124*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_1 | ED_CR_STP);
125*58a2b000SEvgeniy Ivanov 
126*58a2b000SEvgeniy Ivanov 	/* Copy out our station address. */
127*58a2b000SEvgeniy Ivanov 	for (i = 0; i < 6; ++i)
128*58a2b000SEvgeniy Ivanov 		NIC_PUT(ED_P1_PAR0 + i, eth_myaddr[i]);
129*58a2b000SEvgeniy Ivanov 
130*58a2b000SEvgeniy Ivanov 	/*
131*58a2b000SEvgeniy Ivanov 	 * Set current page pointer to one page after the boundary pointer, as
132*58a2b000SEvgeniy Ivanov 	 * recommended in the National manual.
133*58a2b000SEvgeniy Ivanov 	 */
134*58a2b000SEvgeniy Ivanov 	next_packet = rec_page_start + 1;
135*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P1_CURR, next_packet);
136*58a2b000SEvgeniy Ivanov 
137*58a2b000SEvgeniy Ivanov 	/* Program command register for page 0. */
138*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P1_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_STP);
139*58a2b000SEvgeniy Ivanov 
140*58a2b000SEvgeniy Ivanov 	/* directed and broadcast */
141*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_RCR, ED_RCR_AB);
142*58a2b000SEvgeniy Ivanov 
143*58a2b000SEvgeniy Ivanov 	/* Take interface out of loopback. */
144*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_TCR, 0);
145*58a2b000SEvgeniy Ivanov 
146*58a2b000SEvgeniy Ivanov 	/* Fire up the interface. */
147*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_STA);
148*58a2b000SEvgeniy Ivanov }
149*58a2b000SEvgeniy Ivanov 
150*58a2b000SEvgeniy Ivanov int
dp8390_config(void)151*58a2b000SEvgeniy Ivanov dp8390_config(void)
152*58a2b000SEvgeniy Ivanov {
153*58a2b000SEvgeniy Ivanov #ifndef _STANDALONE
154*58a2b000SEvgeniy Ivanov 	if (mapio()) {
155*58a2b000SEvgeniy Ivanov 		printf("no IO access\n");
156*58a2b000SEvgeniy Ivanov 		return -1;
157*58a2b000SEvgeniy Ivanov 	}
158*58a2b000SEvgeniy Ivanov 	vmembase = mapmem(dp8390_membase, dp8390_memsize);
159*58a2b000SEvgeniy Ivanov 	if (!vmembase) {
160*58a2b000SEvgeniy Ivanov 		printf("no memory access\n");
161*58a2b000SEvgeniy Ivanov 		return -1;
162*58a2b000SEvgeniy Ivanov 	}
163*58a2b000SEvgeniy Ivanov #endif
164*58a2b000SEvgeniy Ivanov 
165*58a2b000SEvgeniy Ivanov 	rec_page_start = TX_PAGE_START + ED_TXBUF_SIZE;
166*58a2b000SEvgeniy Ivanov 	rec_page_stop = TX_PAGE_START + (dp8390_memsize >> ED_PAGE_SHIFT);
167*58a2b000SEvgeniy Ivanov 
168*58a2b000SEvgeniy Ivanov 	dp8390_init();
169*58a2b000SEvgeniy Ivanov 
170*58a2b000SEvgeniy Ivanov 	return 0;
171*58a2b000SEvgeniy Ivanov }
172*58a2b000SEvgeniy Ivanov 
173*58a2b000SEvgeniy Ivanov void
dp8390_stop(void)174*58a2b000SEvgeniy Ivanov dp8390_stop(void)
175*58a2b000SEvgeniy Ivanov {
176*58a2b000SEvgeniy Ivanov 	int n = 5000;
177*58a2b000SEvgeniy Ivanov 
178*58a2b000SEvgeniy Ivanov 	/* Stop everything on the interface, and select page 0 registers. */
179*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_STP);
180*58a2b000SEvgeniy Ivanov 
181*58a2b000SEvgeniy Ivanov 	/*
182*58a2b000SEvgeniy Ivanov 	 * Wait for interface to enter stopped state, but limit # of checks to
183*58a2b000SEvgeniy Ivanov 	 * 'n' (about 5ms).  It shouldn't even take 5us on modern DS8390's, but
184*58a2b000SEvgeniy Ivanov 	 * just in case it's an old one.
185*58a2b000SEvgeniy Ivanov 	 */
186*58a2b000SEvgeniy Ivanov 	while (((NIC_GET(ED_P0_ISR) & ED_ISR_RST) == 0) && --n)
187*58a2b000SEvgeniy Ivanov 		continue;
188*58a2b000SEvgeniy Ivanov 
189*58a2b000SEvgeniy Ivanov #ifndef _STANDALONE
190*58a2b000SEvgeniy Ivanov 	unmapmem(vmembase, dp8390_memsize);
191*58a2b000SEvgeniy Ivanov #endif
192*58a2b000SEvgeniy Ivanov }
193*58a2b000SEvgeniy Ivanov 
194*58a2b000SEvgeniy Ivanov int
EtherSend(char * pkt,int len)195*58a2b000SEvgeniy Ivanov EtherSend(char *pkt, int len)
196*58a2b000SEvgeniy Ivanov {
197*58a2b000SEvgeniy Ivanov #ifdef SUPPORT_NE2000
198*58a2b000SEvgeniy Ivanov 	ne2000_writemem(pkt, dp8390_membase, len);
199*58a2b000SEvgeniy Ivanov #else
200*58a2b000SEvgeniy Ivanov #ifdef _STANDALONE
201*58a2b000SEvgeniy Ivanov 	vpbcopy(pkt, (void *)dp8390_membase, len);
202*58a2b000SEvgeniy Ivanov #else
203*58a2b000SEvgeniy Ivanov 	bbcopy(pkt, vmembase, len);
204*58a2b000SEvgeniy Ivanov #endif
205*58a2b000SEvgeniy Ivanov #endif
206*58a2b000SEvgeniy Ivanov 
207*58a2b000SEvgeniy Ivanov 	/* Set TX buffer start page. */
208*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_TPSR, TX_PAGE_START);
209*58a2b000SEvgeniy Ivanov 
210*58a2b000SEvgeniy Ivanov 	/* Set TX length. */
211*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_TBCR0, len < 60 ? 60 : len);
212*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_TBCR1, len >> 8);
213*58a2b000SEvgeniy Ivanov 
214*58a2b000SEvgeniy Ivanov 	/* Set page 0, remote DMA complete, transmit packet, and *start*. */
215*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_TXP | ED_CR_STA);
216*58a2b000SEvgeniy Ivanov 
217*58a2b000SEvgeniy Ivanov 	return len;
218*58a2b000SEvgeniy Ivanov }
219*58a2b000SEvgeniy Ivanov 
220*58a2b000SEvgeniy Ivanov static void
dp8390_read(int buf,char * dest,u_short len)221*58a2b000SEvgeniy Ivanov dp8390_read(int buf, char *dest, u_short len)
222*58a2b000SEvgeniy Ivanov {
223*58a2b000SEvgeniy Ivanov 	u_short tmp_amount;
224*58a2b000SEvgeniy Ivanov 
225*58a2b000SEvgeniy Ivanov 	/* Does copy wrap to lower addr in ring buffer? */
226*58a2b000SEvgeniy Ivanov 	if (buf + len > dp8390_membase + dp8390_memsize) {
227*58a2b000SEvgeniy Ivanov 		tmp_amount = dp8390_membase + dp8390_memsize - buf;
228*58a2b000SEvgeniy Ivanov 
229*58a2b000SEvgeniy Ivanov 		/* Copy amount up to end of NIC memory. */
230*58a2b000SEvgeniy Ivanov #ifdef SUPPORT_NE2000
231*58a2b000SEvgeniy Ivanov 		ne2000_readmem(buf, dest, tmp_amount);
232*58a2b000SEvgeniy Ivanov #else
233*58a2b000SEvgeniy Ivanov #ifdef _STANDALONE
234*58a2b000SEvgeniy Ivanov 		pvbcopy((void *)buf, dest, tmp_amount);
235*58a2b000SEvgeniy Ivanov #else
236*58a2b000SEvgeniy Ivanov 		bbcopy(vmembase + buf - dp8390_membase, dest, tmp_amount);
237*58a2b000SEvgeniy Ivanov #endif
238*58a2b000SEvgeniy Ivanov #endif
239*58a2b000SEvgeniy Ivanov 
240*58a2b000SEvgeniy Ivanov 		len -= tmp_amount;
241*58a2b000SEvgeniy Ivanov 		buf = RX_BUFBASE + (rec_page_start << ED_PAGE_SHIFT);
242*58a2b000SEvgeniy Ivanov 		dest += tmp_amount;
243*58a2b000SEvgeniy Ivanov 	}
244*58a2b000SEvgeniy Ivanov #ifdef SUPPORT_NE2000
245*58a2b000SEvgeniy Ivanov 	ne2000_readmem(buf, dest, len);
246*58a2b000SEvgeniy Ivanov #else
247*58a2b000SEvgeniy Ivanov #ifdef _STANDALONE
248*58a2b000SEvgeniy Ivanov 	pvbcopy((void *)buf, dest, len);
249*58a2b000SEvgeniy Ivanov #else
250*58a2b000SEvgeniy Ivanov 	bbcopy(vmembase + buf - dp8390_membase, dest, len);
251*58a2b000SEvgeniy Ivanov #endif
252*58a2b000SEvgeniy Ivanov #endif
253*58a2b000SEvgeniy Ivanov }
254*58a2b000SEvgeniy Ivanov 
255*58a2b000SEvgeniy Ivanov int
EtherReceive(char * pkt,int maxlen)256*58a2b000SEvgeniy Ivanov EtherReceive(char *pkt, int maxlen)
257*58a2b000SEvgeniy Ivanov {
258*58a2b000SEvgeniy Ivanov 	struct dp8390_ring packet_hdr;
259*58a2b000SEvgeniy Ivanov 	int packet_ptr;
260*58a2b000SEvgeniy Ivanov 	u_short len;
261*58a2b000SEvgeniy Ivanov 	u_char boundary, current;
262*58a2b000SEvgeniy Ivanov #ifdef DP8390_OLDCHIPS
263*58a2b000SEvgeniy Ivanov 	u_char nlen;
264*58a2b000SEvgeniy Ivanov #endif
265*58a2b000SEvgeniy Ivanov 
266*58a2b000SEvgeniy Ivanov 	if (!(NIC_GET(ED_P0_RSR) & ED_RSR_PRX))
267*58a2b000SEvgeniy Ivanov 		return 0; /* XXX error handling */
268*58a2b000SEvgeniy Ivanov 
269*58a2b000SEvgeniy Ivanov 	/* Set NIC to page 1 registers to get 'current' pointer. */
270*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_1 | ED_CR_STA);
271*58a2b000SEvgeniy Ivanov 
272*58a2b000SEvgeniy Ivanov 	/*
273*58a2b000SEvgeniy Ivanov 	 * 'sc->next_packet' is the logical beginning of the ring-buffer - i.e.
274*58a2b000SEvgeniy Ivanov 	 * it points to where new data has been buffered.  The 'CURR' (current)
275*58a2b000SEvgeniy Ivanov 	 * register points to the logical end of the ring-buffer - i.e. it
276*58a2b000SEvgeniy Ivanov 	 * points to where additional new data will be added.  We loop here
277*58a2b000SEvgeniy Ivanov 	 * until the logical beginning equals the logical end (or in other
278*58a2b000SEvgeniy Ivanov 	 * words, until the ring-buffer is empty).
279*58a2b000SEvgeniy Ivanov 	 */
280*58a2b000SEvgeniy Ivanov 	current = NIC_GET(ED_P1_CURR);
281*58a2b000SEvgeniy Ivanov 
282*58a2b000SEvgeniy Ivanov 	/* Set NIC to page 0 registers to update boundary register. */
283*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P1_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_STA);
284*58a2b000SEvgeniy Ivanov 
285*58a2b000SEvgeniy Ivanov 	if (next_packet == current)
286*58a2b000SEvgeniy Ivanov 		return 0;
287*58a2b000SEvgeniy Ivanov 
288*58a2b000SEvgeniy Ivanov 	/* Get pointer to this buffer's header structure. */
289*58a2b000SEvgeniy Ivanov 	packet_ptr = RX_BUFBASE + (next_packet << ED_PAGE_SHIFT);
290*58a2b000SEvgeniy Ivanov 
291*58a2b000SEvgeniy Ivanov 	/*
292*58a2b000SEvgeniy Ivanov 	 * The byte count includes a 4 byte header that was added by
293*58a2b000SEvgeniy Ivanov 	 * the NIC.
294*58a2b000SEvgeniy Ivanov 	 */
295*58a2b000SEvgeniy Ivanov #ifdef SUPPORT_NE2000
296*58a2b000SEvgeniy Ivanov 	ne2000_readmem(packet_ptr, (void *)&packet_hdr, 4);
297*58a2b000SEvgeniy Ivanov #else
298*58a2b000SEvgeniy Ivanov #ifdef _STANDALONE
299*58a2b000SEvgeniy Ivanov 	pvbcopy((void *)packet_ptr, &packet_hdr, 4);
300*58a2b000SEvgeniy Ivanov #else
301*58a2b000SEvgeniy Ivanov 	bbcopy(vmembase + packet_ptr - dp8390_membase, &packet_hdr, 4);
302*58a2b000SEvgeniy Ivanov #endif
303*58a2b000SEvgeniy Ivanov #endif
304*58a2b000SEvgeniy Ivanov 
305*58a2b000SEvgeniy Ivanov 	len = packet_hdr.count;
306*58a2b000SEvgeniy Ivanov 
307*58a2b000SEvgeniy Ivanov #ifdef DP8390_OLDCHIPS
308*58a2b000SEvgeniy Ivanov 	/*
309*58a2b000SEvgeniy Ivanov 	 * Try do deal with old, buggy chips that sometimes duplicate
310*58a2b000SEvgeniy Ivanov 	 * the low byte of the length into the high byte.  We do this
311*58a2b000SEvgeniy Ivanov 	 * by simply ignoring the high byte of the length and always
312*58a2b000SEvgeniy Ivanov 	 * recalculating it.
313*58a2b000SEvgeniy Ivanov 	 *
314*58a2b000SEvgeniy Ivanov 	 * NOTE: sc->next_packet is pointing at the current packet.
315*58a2b000SEvgeniy Ivanov 	 */
316*58a2b000SEvgeniy Ivanov 	if (packet_hdr.next_packet >= next_packet)
317*58a2b000SEvgeniy Ivanov 		nlen = (packet_hdr.next_packet - next_packet);
318*58a2b000SEvgeniy Ivanov 	else
319*58a2b000SEvgeniy Ivanov 		nlen = ((packet_hdr.next_packet - rec_page_start) +
320*58a2b000SEvgeniy Ivanov 			(rec_page_stop - next_packet));
321*58a2b000SEvgeniy Ivanov 	--nlen;
322*58a2b000SEvgeniy Ivanov 	if ((len & ED_PAGE_MASK) + sizeof(packet_hdr) > ED_PAGE_SIZE)
323*58a2b000SEvgeniy Ivanov 		--nlen;
324*58a2b000SEvgeniy Ivanov 	len = (len & ED_PAGE_MASK) | (nlen << ED_PAGE_SHIFT);
325*58a2b000SEvgeniy Ivanov #ifdef DIAGNOSTIC
326*58a2b000SEvgeniy Ivanov 	if (len != packet_hdr.count) {
327*58a2b000SEvgeniy Ivanov 		printf(IFNAME ": length does not match next packet pointer\n");
328*58a2b000SEvgeniy Ivanov 		printf(IFNAME ": len %04x nlen %04x start %02x "
329*58a2b000SEvgeniy Ivanov 		       "first %02x curr %02x next %02x stop %02x\n",
330*58a2b000SEvgeniy Ivanov 		       packet_hdr.count, len,
331*58a2b000SEvgeniy Ivanov 		       rec_page_start, next_packet, current,
332*58a2b000SEvgeniy Ivanov 		       packet_hdr.next_packet, rec_page_stop);
333*58a2b000SEvgeniy Ivanov 	}
334*58a2b000SEvgeniy Ivanov #endif
335*58a2b000SEvgeniy Ivanov #endif
336*58a2b000SEvgeniy Ivanov 
337*58a2b000SEvgeniy Ivanov 	if (packet_hdr.next_packet < rec_page_start ||
338*58a2b000SEvgeniy Ivanov 	    packet_hdr.next_packet >= rec_page_stop)
339*58a2b000SEvgeniy Ivanov 		panic(IFNAME ": RAM corrupt");
340*58a2b000SEvgeniy Ivanov 
341*58a2b000SEvgeniy Ivanov 	len -= sizeof(struct dp8390_ring);
342*58a2b000SEvgeniy Ivanov 	if (len < maxlen) {
343*58a2b000SEvgeniy Ivanov 		/* Go get packet. */
344*58a2b000SEvgeniy Ivanov 		dp8390_read(packet_ptr + sizeof(struct dp8390_ring),
345*58a2b000SEvgeniy Ivanov 			    pkt, len);
346*58a2b000SEvgeniy Ivanov 	} else
347*58a2b000SEvgeniy Ivanov 		len = 0;
348*58a2b000SEvgeniy Ivanov 
349*58a2b000SEvgeniy Ivanov 	/* Update next packet pointer. */
350*58a2b000SEvgeniy Ivanov 	next_packet = packet_hdr.next_packet;
351*58a2b000SEvgeniy Ivanov 
352*58a2b000SEvgeniy Ivanov 	/*
353*58a2b000SEvgeniy Ivanov 	 * Update NIC boundary pointer - being careful to keep it one
354*58a2b000SEvgeniy Ivanov 	 * buffer behind (as recommended by NS databook).
355*58a2b000SEvgeniy Ivanov 	 */
356*58a2b000SEvgeniy Ivanov 	boundary = next_packet - 1;
357*58a2b000SEvgeniy Ivanov 	if (boundary < rec_page_start)
358*58a2b000SEvgeniy Ivanov 		boundary = rec_page_stop - 1;
359*58a2b000SEvgeniy Ivanov 	NIC_PUT(ED_P0_BNRY, boundary);
360*58a2b000SEvgeniy Ivanov 
361*58a2b000SEvgeniy Ivanov 	return len;
362*58a2b000SEvgeniy Ivanov }
363