aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/fec_8xx/fec_main.c
blob: 6348fb93ca9cc9cbbac100ec11762c1f9d8ea81c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
/*
 * Fast Ethernet Controller (FEC) driver for Motorola MPC8xx.
 *
 * Copyright (c) 2003 Intracom S.A. 
 *  by Pantelis Antoniou <panto@intracom.gr>
 *
 * Heavily based on original FEC driver by Dan Malek <dan@embeddededge.com>
 * and modifications by Joakim Tjernlund <joakim.tjernlund@lumentis.se>
 *
 * Released under the GPL
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/bitops.h>
#include <linux/dma-mapping.h>

#include <asm/8xx_immap.h>
#include <asm/pgtable.h>
#include <asm/mpc8xx.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/commproc.h>

#include "fec_8xx.h"

/*************************************************/

#define FEC_MAX_MULTICAST_ADDRS	64

/*************************************************/

static char version[] __devinitdata =
    DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")" "\n";

MODULE_AUTHOR("Pantelis Antoniou <panto@intracom.gr>");
MODULE_DESCRIPTION("Motorola 8xx FEC ethernet driver");
MODULE_LICENSE("GPL");

int fec_8xx_debug = -1;		/* -1 == use FEC_8XX_DEF_MSG_ENABLE as value */
module_param(fec_8xx_debug, int, 0);
MODULE_PARM_DESC(fec_8xx_debug,
		 "FEC 8xx bitmapped debugging message enable value");


/*************************************************/

/*
 * Delay to wait for FEC reset command to complete (in us) 
 */
#define FEC_RESET_DELAY		50

/*****************************************************************************************/

static void fec_whack_reset(fec_t * fecp)
{
	int i;

	/*
	 * Whack a reset.  We should wait for this.  
	 */
	FW(fecp, ecntrl, FEC_ECNTRL_PINMUX | FEC_ECNTRL_RESET);
	for (i = 0;
	     (FR(fecp, ecntrl) & FEC_ECNTRL_RESET) != 0 && i < FEC_RESET_DELAY;
	     i++)
		udelay(1);

	if (i == FEC_RESET_DELAY)
		printk(KERN_WARNING "FEC Reset timeout!\n");

}

/****************************************************************************/

/*
 * Transmitter timeout.  
 */
#define TX_TIMEOUT (2*HZ)

/****************************************************************************/

/*
 * Returns the CRC needed when filling in the hash table for
 * multicast group filtering
 * pAddr must point to a MAC address (6 bytes)
 */
static __u32 fec_mulicast_calc_crc(char *pAddr)
{
	u8 byte;
	int byte_count;
	int bit_count;
	__u32 crc = 0xffffffff;
	u8 msb;

	for (byte_count = 0; byte_count < 6; byte_count++) {
		byte = pAddr[byte_count];
		for (bit_count = 0; bit_count < 8; bit_count++) {
			msb = crc >> 31;
			crc <<= 1;
			if (msb ^ (byte & 0x1)) {
				crc ^= FEC_CRC_POLY;
			}
			byte >>= 1;
		}
	}
	return (crc);
}

/*
 * Set or clear the multicast filter for this adaptor.
 * Skeleton taken from sunlance driver.
 * The CPM Ethernet implementation allows Multicast as well as individual
 * MAC address filtering.  Some of the drivers check to make sure it is
 * a group multicast address, and discard those that are not.  I guess I
 * will do the same for now, but just remove the test if you want
 * individual filtering as well (do the upper net layers want or support
 * this kind of feature?).
 */
static void fec_set_multicast_list(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	fec_t *fecp = fep->fecp;
	struct dev_mc_list *pmc;
	__u32 crc;
	int temp;
	__u32 csrVal;
	int hash_index;
	__u32 hthi, htlo;
	unsigned long flags;


	if ((dev->flags & IFF_PROMISC) != 0) {

		spin_lock_irqsave(&fep->lock, flags);
		FS(fecp, r_cntrl, FEC_RCNTRL_PROM);
		spin_unlock_irqrestore(&fep->lock, flags);

		/*
		 * Log any net taps. 
		 */
		printk(KERN_WARNING DRV_MODULE_NAME
		       ": %s: Promiscuous mode enabled.\n", dev->name);
		return;

	}

	if ((dev->flags & IFF_ALLMULTI) != 0 ||
	    dev->mc_count > FEC_MAX_MULTICAST_ADDRS) {
		/*
		 * Catch all multicast addresses, set the filter to all 1's.
		 */
		hthi = 0xffffffffU;
		htlo = 0xffffffffU;
	} else {
		hthi = 0;
		htlo = 0;

		/*
		 * Now populate the hash table 
		 */
		for (pmc = dev->mc_list; pmc != NULL; pmc = pmc->next) {
			crc = fec_mulicast_calc_crc(pmc->dmi_addr);
			temp = (crc & 0x3f) >> 1;
			hash_index = ((temp & 0x01) << 4) |
				     ((temp & 0x02) << 2) |
				     ((temp & 0x04)) |
				     ((temp & 0x08) >> 2) |
				     ((temp & 0x10) >> 4);
			csrVal = (1 << hash_index);
			if (crc & 1)
				hthi |= csrVal;
			else
				htlo |= csrVal;
		}
	}

	spin_lock_irqsave(&fep->lock, flags);
	FC(fecp, r_cntrl, FEC_RCNTRL_PROM);
	FW(fecp, hash_table_high, hthi);
	FW(fecp, hash_table_low, htlo);
	spin_unlock_irqrestore(&fep->lock, flags);
}

static int fec_set_mac_address(struct net_device *dev, void *addr)
{
	struct sockaddr *mac = addr;
	struct fec_enet_private *fep = netdev_priv(dev);
	struct fec *fecp = fep->fecp;
	int i;
	__u32 addrhi, addrlo;
	unsigned long flags;

	/* Get pointer to SCC area in parameter RAM. */
	for (i = 0; i < 6; i++)
		dev->dev_addr[i] = mac->sa_data[i];

	/*
	 * Set station address. 
	 */
	addrhi = ((__u32) dev->dev_addr[0] << 24) |
		 ((__u32) dev->dev_addr[1] << 16) |
	   	 ((__u32) dev->dev_addr[2] <<  8) |
	    	  (__u32) dev->dev_addr[3];
	addrlo = ((__u32) dev->dev_addr[4] << 24) |
	    	 ((__u32) dev->dev_addr[5] << 16);

	spin_lock_irqsave(&fep->lock, flags);
	FW(fecp, addr_low, addrhi);
	FW(fecp, addr_high, addrlo);
	spin_unlock_irqrestore(&fep->lock, flags);

	return 0;
}

/*
 * This function is called to start or restart the FEC during a link
 * change.  This only happens when switching between half and full
 * duplex.
 */
void fec_restart(struct net_device *dev, int duplex, int speed)
{
#ifdef CONFIG_DUET
	immap_t *immap = (immap_t *) IMAP_ADDR;
	__u32 cptr;
#endif
	struct fec_enet_private *fep = netdev_priv(dev);
	struct fec *fecp = fep->fecp;
	const struct fec_platform_info *fpi = fep->fpi;
	cbd_t *bdp;
	struct sk_buff *skb;
	int i;
	__u32 addrhi, addrlo;

	fec_whack_reset(fep->fecp);

	/*
	 * Set station address. 
	 */
	addrhi = ((__u32) dev->dev_addr[0] << 24) |
		 ((__u32) dev->dev_addr[1] << 16) |
		 ((__u32) dev->dev_addr[2] <<  8) |
		 (__u32) dev->dev_addr[3];
	addrlo = ((__u32) dev->dev_addr[4] << 24) |
		 ((__u32) dev->dev_addr[5] << 16);
	FW(fecp, addr_low, addrhi);
	FW(fecp, addr_high, addrlo);

	/*
	 * Reset all multicast. 
	 */
	FW(fecp, hash_table_high, 0);
	FW(fecp, hash_table_low, 0);

	/*
	 * Set maximum receive buffer size. 
	 */
	FW(fecp, r_buff_size, PKT_MAXBLR_SIZE);
	FW(fecp, r_hash, PKT_MAXBUF_SIZE);

	/*
	 * Set receive and transmit descriptor base. 
	 */
	FW(fecp, r_des_start, iopa((__u32) (fep->rx_bd_base)));
	FW(fecp, x_des_start, iopa((__u32) (fep->tx_bd_base)));

	fep->dirty_tx = fep->cur_tx = fep->tx_bd_base;
	fep->tx_free = fep->tx_ring;
	fep->cur_rx = fep->rx_bd_base;

	/*
	 * Reset SKB receive buffers 
	 */
	for (i = 0; i < fep->rx_ring; i++) {
		if ((skb = fep->rx_skbuff[i]) == NULL)
			continue;
		fep->rx_skbuff[i] = NULL;
		dev_kfree_skb(skb);
	}

	/*
	 * Initialize the receive buffer descriptors. 
	 */
	for (i = 0, bdp = fep->rx_bd_base; i < fep->rx_ring; i++, bdp++) {
		skb = dev_alloc_skb(ENET_RX_FRSIZE);
		if (skb == NULL) {
			printk(KERN_WARNING DRV_MODULE_NAME
			       ": %s Memory squeeze, unable to allocate skb\n",
			       dev->name);
			fep->stats.rx_dropped++;
			break;
		}
		fep->rx_skbuff[i] = skb;
		skb->dev = dev;
		CBDW_BUFADDR(bdp, dma_map_single(NULL, skb->data,
					 L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
					 DMA_FROM_DEVICE));
		CBDW_DATLEN(bdp, 0);	/* zero */
		CBDW_SC(bdp, BD_ENET_RX_EMPTY |
			((i < fep->rx_ring - 1) ? 0 : BD_SC_WRAP));
	}
	/*
	 * if we failed, fillup remainder 
	 */
	for (; i < fep->rx_ring; i++, bdp++) {
		fep->rx_skbuff[i] = NULL;
		CBDW_SC(bdp, (i < fep->rx_ring - 1) ? 0 : BD_SC_WRAP);
	}

	/*
	 * Reset SKB transmit buffers.  
	 */
	for (i = 0; i < fep->tx_ring; i++) {
		if ((skb = fep->tx_skbuff[i]) == NULL)
			continue;
		fep->tx_skbuff[i] = NULL;
		dev_kfree_skb(skb);
	}

	/*
	 * ...and the same for transmit.  
	 */
	for (i = 0, bdp = fep->tx_bd_base; i < fep->tx_ring; i++, bdp++) {
		fep->tx_skbuff[i] = NULL;
		CBDW_BUFADDR(bdp, virt_to_bus(NULL));
		CBDW_DATLEN(bdp, 0);
		CBDW_SC(bdp, (i < fep->tx_ring - 1) ? 0 : BD_SC_WRAP);
	}

	/*
	 * Enable big endian and don't care about SDMA FC. 
	 */
	FW(fecp, fun_code, 0x78000000);

	/*
	 * Set MII speed. 
	 */
	FW(fecp, mii_speed, fep->fec_phy_speed);

	/*
	 * Clear any outstanding interrupt. 
	 */
	FW(fecp, ievent, 0xffc0);
	FW(fecp, ivec, (fpi->fec_irq / 2) << 29);

	/*
	 * adjust to speed (only for DUET & RMII) 
	 */
#ifdef CONFIG_DUET
	cptr = in_be32(&immap->im_cpm.cp_cptr);
	switch (fpi->fec_no) {
	case 0:
		/*
		 * check if in RMII mode 
		 */
		if ((cptr & 0x100) == 0)
			break;

		if (speed == 10)
			cptr |= 0x0000010;
		else if (speed == 100)
			cptr &= ~0x0000010;
		break;
	case 1:
		/*
		 * check if in RMII mode 
		 */
		if ((cptr & 0x80) == 0)
			break;

		if (speed == 10)
			cptr |= 0x0000008;
		else if (speed == 100)
			cptr &= ~0x0000008;
		break;
	default:
		break;
	}
	out_be32(&immap->im_cpm.cp_cptr, cptr);
#endif

	FW(fecp, r_cntrl, FEC_RCNTRL_MII_MODE);	/* MII enable */
	/*
	 * adjust to duplex mode 
	 */
	if (duplex) {
		FC(fecp, r_cntrl, FEC_RCNTRL_DRT);
		FS(fecp, x_cntrl, FEC_TCNTRL_FDEN);	/* FD enable */
	} else {
		FS(fecp, r_cntrl, FEC_RCNTRL_DRT);
		FC(fecp, x_cntrl, FEC_TCNTRL_FDEN);	/* FD disable */
	}

	/*
	 * Enable interrupts we wish to service. 
	 */
	FW(fecp, imask, FEC_ENET_TXF | FEC_ENET_TXB |
	   FEC_ENET_RXF | FEC_ENET_RXB);

	/*
	 * And last, enable the transmit and receive processing. 
	 */
	FW(fecp, ecntrl, FEC_ECNTRL_PINMUX | FEC_ECNTRL_ETHER_EN);
	FW(fecp, r_des_active, 0x01000000);
}

void fec_stop(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	fec_t *fecp = fep->fecp;
	struct sk_buff *skb;
	int i;

	if ((FR(fecp, ecntrl) & FEC_ECNTRL_ETHER_EN) == 0)
		return;		/* already down */

	FW(fecp, x_cntrl, 0x01);	/* Graceful transmit stop */
	for (i = 0; ((FR(fecp, ievent) & 0x10000000) == 0) &&
	     i < FEC_RESET_DELAY; i++)
		udelay(1);

	if (i == FEC_RESET_DELAY)
		printk(KERN_WARNING DRV_MODULE_NAME
		       ": %s FEC timeout on graceful transmit stop\n",
		       dev->name);
	/*
	 * Disable FEC. Let only MII interrupts. 
	 */
	FW(fecp, imask, 0);
	FW(fecp, ecntrl, ~FEC_ECNTRL_ETHER_EN);

	/*
	 * Reset SKB transmit buffers.  
	 */
	for (i = 0; i < fep->tx_ring; i++) {
		if ((skb = fep->tx_skbuff[i]) == NULL)
			continue;
		fep->tx_skbuff[i] = NULL;
		dev_kfree_skb(skb);
	}

	/*
	 * Reset SKB receive buffers 
	 */
	for (i = 0; i < fep->rx_ring; i++) {
		if ((skb = fep->rx_skbuff[i]) == NULL)
			continue;
		fep->rx_skbuff[i] = NULL;
		dev_kfree_skb(skb);
	}
}

/* common receive function */
static int fec_enet_rx_common(struct fec_enet_private *ep,
			      struct net_device *dev, int budget)
{
	fec_t *fecp = fep->fecp;
	const struct fec_platform_info *fpi = fep->fpi;
	cbd_t *bdp;
	struct sk_buff *skb, *skbn, *skbt;
	int received = 0;
	__u16 pkt_len, sc;
	int curidx;

	if (fpi->use_napi) {
		if (!netif_running(dev))
			return 0;
	}

	/*
	 * First, grab all of the stats for the incoming packet.
	 * These get messed up if we get called due to a busy condition.
	 */
	bdp = fep->cur_rx;

	/* clear RX status bits for napi*/
	if (fpi->use_napi)
		FW(fecp, ievent, FEC_ENET_RXF | FEC_ENET_RXB);

	while (((sc = CBDR_SC(bdp)) & BD_ENET_RX_EMPTY) == 0) {

		curidx = bdp - fep->rx_bd_base;

		/*
		 * Since we have allocated space to hold a complete frame,
		 * the last indicator should be set.
		 */
		if ((sc & BD_ENET_RX_LAST) == 0)
			printk(KERN_WARNING DRV_MODULE_NAME
			       ": %s rcv is not +last\n",
			       dev->name);

		/*
		 * Check for errors. 
		 */
		if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_CL |
			  BD_ENET_RX_NO | BD_ENET_RX_CR | BD_ENET_RX_OV)) {
			fep->stats.rx_errors++;
			/* Frame too long or too short. */
			if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH))
				fep->stats.rx_length_errors++;
			/* Frame alignment */
			if (sc & (BD_ENET_RX_NO | BD_ENET_RX_CL))
				fep->stats.rx_frame_errors++;
			/* CRC Error */
			if (sc & BD_ENET_RX_CR)
				fep->stats.rx_crc_errors++;
			/* FIFO overrun */
			if (sc & BD_ENET_RX_OV)
				fep->stats.rx_crc_errors++;

			skbn = fep->rx_skbuff[curidx];
			BUG_ON(skbn == NULL);

		} else {
			skb = fep->rx_skbuff[curidx];
			BUG_ON(skb == NULL);

			/*
			 * Process the incoming frame.
			 */
			fep->stats.rx_packets++;
			pkt_len = CBDR_DATLEN(bdp) - 4;	/* remove CRC */
			fep->stats.rx_bytes += pkt_len + 4;

			if (pkt_len <= fpi->rx_copybreak) {
				/* +2 to make IP header L1 cache aligned */
				skbn = dev_alloc_skb(pkt_len + 2);
				if (skbn != NULL) {
					skb_reserve(skbn, 2);	/* align IP header */
					skb_copy_from_linear_data(skb,
								  skbn->data,
								  pkt_len);
					/* swap */
					skbt = skb;
					skb = skbn;
					skbn = skbt;
				}
			} else
				skbn = dev_alloc_skb(ENET_RX_FRSIZE);

			if (skbn != NULL) {
				skb_put(skb, pkt_len);	/* Make room */
				skb->protocol = eth_type_trans(skb, dev);
				received++;
				if (!fpi->use_napi)
					netif_rx(skb);
				else
					netif_receive_skb(skb);
			} else {
				printk(KERN_WARNING DRV_MODULE_NAME
				       ": %s Memory squeeze, dropping packet.\n",
				       dev->name);
				fep->stats.rx_dropped++;
				skbn = skb;
			}
		}

		fep->rx_skbuff[curidx] = skbn;
		CBDW_BUFADDR(bdp, dma_map_single(NULL, skbn->data,
						 L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
						 DMA_FROM_DEVICE));
		CBDW_DATLEN(bdp, 0);
		CBDW_SC(bdp, (sc & ~BD_ENET_RX_STATS) | BD_ENET_RX_EMPTY);

		/*
		 * Update BD pointer to next entry. 
		 */
		if ((sc & BD_ENET_RX_WRAP) == 0)
			bdp++;
		else
			bdp = fep->rx_bd_base;

		/*
		 * Doing this here will keep the FEC running while we process
		 * incoming frames.  On a heavily loaded network, we should be
		 * able to keep up at the expense of system resources.
		 */
		FW(fecp, r_des_active, 0x01000000);

		if (received >= budget)
			break;

	}

	fep->cur_rx = bdp;

	if (fpi->use_napi) {
		if (received < budget) {
			netif_rx_complete(dev, &fep->napi);

			/* enable RX interrupt bits */
			FS(fecp, imask, FEC_ENET_RXF | FEC_ENET_RXB);
		}
	}

	return received;
}

static void fec_enet_tx(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	cbd_t *bdp;
	struct sk_buff *skb;
	int dirtyidx, do_wake;
	__u16 sc;

	spin_lock(&fep->lock);
	bdp = fep->dirty_tx;

	do_wake = 0;
	while (((sc = CBDR_SC(bdp)) & BD_ENET_TX_READY) == 0) {

		dirtyidx = bdp - fep->tx_bd_base;

		if (fep->tx_free == fep->tx_ring)
			break;

		skb = fep->tx_skbuff[dirtyidx];

		/*
		 * Check for errors. 
		 */
		if (sc & (BD_ENET_TX_HB | BD_ENET_TX_LC |
			  BD_ENET_TX_RL | BD_ENET_TX_UN | BD_ENET_TX_CSL)) {
			fep->stats.tx_errors++;
			if (sc & BD_ENET_TX_HB)	/* No heartbeat */
				fep->stats.tx_heartbeat_errors++;
			if (sc & BD_ENET_TX_LC)	/* Late collision */
				fep->stats.tx_window_errors++;
			if (sc & BD_ENET_TX_RL)	/* Retrans limit */
				fep->stats.tx_aborted_errors++;
			if (sc & BD_ENET_TX_UN)	/* Underrun */
				fep->stats.tx_fifo_errors++;
			if (sc & BD_ENET_TX_CSL)	/* Carrier lost */
				fep->stats.tx_carrier_errors++;
		} else
			fep->stats.tx_packets++;

		if (sc & BD_ENET_TX_READY)
			printk(KERN_WARNING DRV_MODULE_NAME
			       ": %s HEY! Enet xmit interrupt and TX_READY.\n",
			       dev->name);

		/*
		 * Deferred means some collisions occurred during transmit,
		 * but we eventually sent the packet OK.
		 */
		if (sc & BD_ENET_TX_DEF)
			fep->stats.collisions++;

		/*
		 * Free the sk buffer associated with this last transmit. 
		 */
		dev_kfree_skb_irq(skb);
		fep->tx_skbuff[dirtyidx] = NULL;

		/*
		 * Update pointer to next buffer descriptor to be transmitted. 
		 */
		if ((sc & BD_ENET_TX_WRAP) == 0)
			bdp++;
		else
			bdp = fep->tx_bd_base;

		/*
		 * Since we have freed up a buffer, the ring is no longer
		 * full.
		 */
		if (!fep->tx_free++)
			do_wake = 1;
	}

	fep->dirty_tx = bdp;

	spin_unlock(&fep->lock);

	if (do_wake && netif_queue_stopped(dev))
		netif_wake_queue(dev);
}

/*
 * The interrupt handler.
 * This is called from the MPC core interrupt.
 */
static irqreturn_t
fec_enet_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct fec_enet_private *fep;
	const struct fec_platform_info *fpi;
	fec_t *fecp;
	__u32 int_events;
	__u32 int_events_napi;

	if (unlikely(dev == NULL))
		return IRQ_NONE;

	fep = netdev_priv(dev);
	fecp = fep->fecp;
	fpi = fep->fpi;

	/*
	 * Get the interrupt events that caused us to be here.
	 */
	while ((int_events = FR(fecp, ievent) & FR(fecp, imask)) != 0) {

		if (!fpi->use_napi)
			FW(fecp, ievent, int_events);
		else {
			int_events_napi = int_events & ~(FEC_ENET_RXF | FEC_ENET_RXB);
			FW(fecp, ievent, int_events_napi);
		}

		if ((int_events & (FEC_ENET_HBERR | FEC_ENET_BABR |
				   FEC_ENET_BABT | FEC_ENET_EBERR)) != 0)
			printk(KERN_WARNING DRV_MODULE_NAME
			       ": %s FEC ERROR(s) 0x%x\n",
			       dev->name, int_events);

		if ((int_events & FEC_ENET_RXF) != 0) {
			if (!fpi->use_napi)
				fec_enet_rx_common(fep, dev, ~0);
			else {
				if (netif_rx_schedule_prep(dev, &fep->napi)) {
					/* disable rx interrupts */
					FC(fecp, imask, FEC_ENET_RXF | FEC_ENET_RXB);
					__netif_rx_schedule(dev, &fep->napi);
				} else {
					printk(KERN_ERR DRV_MODULE_NAME
					       ": %s driver bug! interrupt while in poll!\n",
					       dev->name);
					FC(fecp, imask, FEC_ENET_RXF | FEC_ENET_RXB);
				}
			}
		}

		if ((int_events & FEC_ENET_TXF) != 0)
			fec_enet_tx(dev);
	}

	return IRQ_HANDLED;
}

/* This interrupt occurs when the PHY detects a link change. */
static irqreturn_t
fec_mii_link_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = dev_id;
	struct fec_enet_private *fep;
	const struct fec_platform_info *fpi;

	if (unlikely(dev == NULL))
		return IRQ_NONE;

	fep = netdev_priv(dev);
	fpi = fep->fpi;

	if (!fpi->use_mdio)
		return IRQ_NONE;

	/*
	 * Acknowledge the interrupt if possible. If we have not
	 * found the PHY yet we can't process or acknowledge the
	 * interrupt now. Instead we ignore this interrupt for now,
	 * which we can do since it is edge triggered. It will be
	 * acknowledged later by fec_enet_open().
	 */
	if (!fep->phy)
		return IRQ_NONE;

	fec_mii_ack_int(dev);
	fec_mii_link_status_change_check(dev, 0);

	return IRQ_HANDLED;
}


/**********************************************************************************/

static int fec_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	fec_t *fecp = fep->fecp;
	cbd_t *bdp;
	int curidx;
	unsigned long flags;

	spin_lock_irqsave(&fep->tx_lock, flags);

	/*
	 * Fill in a Tx ring entry 
	 */
	bdp = fep->cur_tx;

	if (!fep->tx_free || (CBDR_SC(bdp) & BD_ENET_TX_READY)) {
		netif_stop_queue(dev);
		spin_unlock_irqrestore(&fep->tx_lock, flags);

		/*
		 * Ooops.  All transmit buffers are full.  Bail out.
		 * This should not happen, since the tx queue should be stopped.
		 */
		printk(KERN_WARNING DRV_MODULE_NAME
		       ": %s tx queue full!.\n", dev->name);
		return 1;
	}

	curidx = bdp - fep->tx_bd_base;
	/*
	 * Clear all of the status flags. 
	 */
	CBDC_SC(bdp, BD_ENET_TX_STATS);

	/*
	 * Save skb pointer. 
	 */
	fep->tx_skbuff[curidx] = skb;

	fep->stats.tx_bytes += skb->len;

	/*
	 * Push the data cache so the CPM does not get stale memory data. 
	 */
	CBDW_BUFADDR(bdp, dma_map_single(NULL, skb->data,
					 skb->len, DMA_TO_DEVICE));
	CBDW_DATLEN(bdp, skb->len);

	dev->trans_start = jiffies;

	/*
	 * If this was the last BD in the ring, start at the beginning again. 
	 */
	if ((CBDR_SC(bdp) & BD_ENET_TX_WRAP) == 0)
		fep->cur_tx++;
	else
		fep->cur_tx = fep->tx_bd_base;

	if (!--fep->tx_free)
		netif_stop_queue(dev);

	/*
	 * Trigger transmission start 
	 */
	CBDS_SC(bdp, BD_ENET_TX_READY | BD_ENET_TX_INTR |
		BD_ENET_TX_LAST | BD_ENET_TX_TC);
	FW(fecp, x_des_active, 0x01000000);

	spin_unlock_irqrestore(&fep->tx_lock, flags);

	return 0;
}

static void fec_timeout(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);

	fep->stats.tx_errors++;

	if (fep->tx_free)
		netif_wake_queue(dev);

	/* check link status again */
	fec_mii_link_status_change_check(dev, 0);
}

static int fec_enet_open(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	const struct fec_platform_info *fpi = fep->fpi;
	unsigned long flags;

	napi_enable(&fep->napi);

	/* Install our interrupt handler. */
	if (request_irq(fpi->fec_irq, fec_enet_interrupt, 0, "fec", dev) != 0) {
		printk(KERN_ERR DRV_MODULE_NAME
		       ": %s Could not allocate FEC IRQ!", dev->name);
		napi_disable(&fep->napi);
		return -EINVAL;
	}

	/* Install our phy interrupt handler */
	if (fpi->phy_irq != -1 && 
		request_irq(fpi->phy_irq, fec_mii_link_interrupt, 0, "fec-phy",
				dev) != 0) {
		printk(KERN_ERR DRV_MODULE_NAME
		       ": %s Could not allocate PHY IRQ!", dev->name);
		free_irq(fpi->fec_irq, dev);
		napi_disable(&fep->napi);
		return -EINVAL;
	}

	if (fpi->use_mdio) {
		fec_mii_startup(dev);
		netif_carrier_off(dev);
		fec_mii_link_status_change_check(dev, 1);
	} else {
		spin_lock_irqsave(&fep->lock, flags);
		fec_restart(dev, 1, 100);	/* XXX this sucks */
		spin_unlock_irqrestore(&fep->lock, flags);

		netif_carrier_on(dev);
		netif_start_queue(dev);
	}
	return 0;
}

static int fec_enet_close(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	const struct fec_platform_info *fpi = fep->fpi;
	unsigned long flags;

	netif_stop_queue(dev);
	napi_disable(&fep->napi);
	netif_carrier_off(dev);

	if (fpi->use_mdio)
		fec_mii_shutdown(dev);

	spin_lock_irqsave(&fep->lock, flags);
	fec_stop(dev);
	spin_unlock_irqrestore(&fep->lock, flags);

	/* release any irqs */
	if (fpi->phy_irq != -1)
		free_irq(fpi->phy_irq, dev);
	free_irq(fpi->fec_irq, dev);

	return 0;
}

static struct net_device_stats *fec_enet_get_stats(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	return &fep->stats;
}

static int fec_enet_poll(struct napi_struct *napi, int budget)
{
	struct fec_enet_private *fep = container_of(napi, struct fec_enet_private, napi);
	struct net_device *dev = fep->dev;

	return fec_enet_rx_common(fep, dev, budget);
}

/*************************************************************************/

static void fec_get_drvinfo(struct net_device *dev,
			    struct ethtool_drvinfo *info)
{
	strcpy(info->driver, DRV_MODULE_NAME);
	strcpy(info->version, DRV_MODULE_VERSION);
}

static int fec_get_regs_len(struct net_device *dev)
{
	return sizeof(fec_t);
}

static void fec_get_regs(struct net_device *dev, struct ethtool_regs *regs,
			 void *p)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	unsigned long flags;

	if (regs->len < sizeof(fec_t))
		return;

	regs->version = 0;
	spin_lock_irqsave(&fep->lock, flags);
	memcpy_fromio(p, fep->fecp, sizeof(fec_t));
	spin_unlock_irqrestore(&fep->lock, flags);
}

static int fec_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	unsigned long flags;
	int rc;

	spin_lock_irqsave(&fep->lock, flags);
	rc = mii_ethtool_gset(&fep->mii_if, cmd);
	spin_unlock_irqrestore(&fep->lock, flags);

	return rc;
}

static int fec_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	unsigned long flags;
	int rc;

	spin_lock_irqsave(&fep->lock, flags);
	rc = mii_ethtool_sset(&fep->mii_if, cmd);
	spin_unlock_irqrestore(&fep->lock, flags);

	return rc;
}

static int fec_nway_reset(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	return mii_nway_restart(&fep->mii_if);
}

static __u32 fec_get_msglevel(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	return fep->msg_enable;
}

static void fec_set_msglevel(struct net_device *dev, __u32 value)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	fep->msg_enable = value;
}

static const struct ethtool_ops fec_ethtool_ops = {
	.get_drvinfo	= fec_get_drvinfo,
	.get_regs_len	= fec_get_regs_len,
	.get_settings	= fec_get_settings,
	.set_settings	= fec_set_settings,
	.nway_reset	= fec_nway_reset,
	.get_link	= ethtool_op_get_link,
	.get_msglevel	= fec_get_msglevel,
	.set_msglevel	= fec_set_msglevel,
	.get_tx_csum	= ethtool_op_get_tx_csum,
	.set_tx_csum	= ethtool_op_set_tx_csum,	/* local! */
	.get_sg		= ethtool_op_get_sg,
	.set_sg		= ethtool_op_set_sg,
	.get_regs	= fec_get_regs,
};

static int fec_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	struct mii_ioctl_data *mii = (struct mii_ioctl_data *)&rq->ifr_data;
	unsigned long flags;
	int rc;

	if (!netif_running(dev))
		return -EINVAL;

	spin_lock_irqsave(&fep->lock, flags);
	rc = generic_mii_ioctl(&fep->mii_if, mii, cmd, NULL);
	spin_unlock_irqrestore(&fep->lock, flags);
	return rc;
}

int fec_8xx_init_one(const struct fec_platform_info *fpi,
		     struct net_device **devp)
{
	immap_t *immap = (immap_t *) IMAP_ADDR;
	static int fec_8xx_version_printed = 0;
	struct net_device *dev = NULL;
	struct fec_enet_private *fep = NULL;
	fec_t *fecp = NULL;
	int i;
	int err = 0;
	int registered = 0;
	__u32 siel;

	*devp = NULL;

	switch (fpi->fec_no) {
	case 0:
		fecp = &((immap_t *) IMAP_ADDR)->im_cpm.cp_fec;
		break;
#ifdef CONFIG_DUET
	case 1:
		fecp = &((immap_t *) IMAP_ADDR)->im_cpm.cp_fec2;
		break;
#endif
	default:
		return -EINVAL;
	}

	if (fec_8xx_version_printed++ == 0)
		printk(KERN_INFO "%s", version);

	i = sizeof(*fep) + (sizeof(struct sk_buff **) *
			    (fpi->rx_ring + fpi->tx_ring));

	dev = alloc_etherdev(i);
	if (!dev) {
		err = -ENOMEM;
		goto err;
	}
	SET_MODULE_OWNER(dev);

	fep = netdev_priv(dev);
	fep->dev = dev;

	/* partial reset of FEC */
	fec_whack_reset(fecp);

	/* point rx_skbuff, tx_skbuff */
	fep->rx_skbuff = (struct sk_buff **)&fep[1];
	fep->tx_skbuff = fep->rx_skbuff + fpi->rx_ring;

	fep->fecp = fecp;
	fep->fpi = fpi;

	/* init locks */
	spin_lock_init(&fep->lock);
	spin_lock_init(&fep->tx_lock);

	/*
	 * Set the Ethernet address. 
	 */
	for (i = 0; i < 6; i++)
		dev->dev_addr[i] = fpi->macaddr[i];

	fep->ring_base = dma_alloc_coherent(NULL,
					    (fpi->tx_ring + fpi->rx_ring) *
					    sizeof(cbd_t), &fep->ring_mem_addr,
					    GFP_KERNEL);
	if (fep->ring_base == NULL) {
		printk(KERN_ERR DRV_MODULE_NAME
		       ": %s dma alloc failed.\n", dev->name);
		err = -ENOMEM;
		goto err;
	}

	/*
	 * Set receive and transmit descriptor base.
	 */
	fep->rx_bd_base = fep->ring_base;
	fep->tx_bd_base = fep->rx_bd_base + fpi->rx_ring;

	/* initialize ring size variables */
	fep->tx_ring = fpi->tx_ring;
	fep->rx_ring = fpi->rx_ring;

	/* SIU interrupt */
	if (fpi->phy_irq != -1 &&
		(fpi->phy_irq >= SIU_IRQ0 && fpi->phy_irq < SIU_LEVEL7)) {

		siel = in_be32(&immap->im_siu_conf.sc_siel);
		if ((fpi->phy_irq & 1) == 0)
			siel |= (0x80000000 >> fpi->phy_irq);
		else
			siel &= ~(0x80000000 >> (fpi->phy_irq & ~1));
		out_be32(&immap->im_siu_conf.sc_siel, siel);
	}

	/*
	 * The FEC Ethernet specific entries in the device structure. 
	 */
	dev->open = fec_enet_open;
	dev->hard_start_xmit = fec_enet_start_xmit;
	dev->tx_timeout = fec_timeout;
	dev->watchdog_timeo = TX_TIMEOUT;
	dev->stop = fec_enet_close;
	dev->get_stats = fec_enet_get_stats;
	dev->set_multicast_list = fec_set_multicast_list;
	dev->set_mac_address = fec_set_mac_address;
	netif_napi_add(dev, &fec->napi,
		       fec_enet_poll, fpi->napi_weight);

	dev->ethtool_ops = &fec_ethtool_ops;
	dev->do_ioctl = fec_ioctl;

	fep->fec_phy_speed =
	    ((((fpi->sys_clk + 4999999) / 2500000) / 2) & 0x3F) << 1;

	init_timer(&fep->phy_timer_list);

	/* partial reset of FEC so that only MII works */
	FW(fecp, mii_speed, fep->fec_phy_speed);
	FW(fecp, ievent, 0xffc0);
	FW(fecp, ivec, (fpi->fec_irq / 2) << 29);
	FW(fecp, imask, 0);
	FW(fecp, r_cntrl, FEC_RCNTRL_MII_MODE);	/* MII enable */
	FW(fecp, ecntrl, FEC_ECNTRL_PINMUX | FEC_ECNTRL_ETHER_EN);

	netif_carrier_off(dev);

	err = register_netdev(dev);
	if (err != 0)
		goto err;
	registered = 1;

	if (fpi->use_mdio) {
		fep->mii_if.dev = dev;
		fep->mii_if.mdio_read = fec_mii_read;
		fep->mii_if.mdio_write = fec_mii_write;
		fep->mii_if.phy_id_mask = 0x1f;
		fep->mii_if.reg_num_mask = 0x1f;
		fep->mii_if.phy_id = fec_mii_phy_id_detect(dev);
	}

	*devp = dev;

	return 0;

      err:
	if (dev != NULL) {
		if (fecp != NULL)
			fec_whack_reset(fecp);

		if (registered)
			unregister_netdev(dev);

		if (fep != NULL) {
			if (fep->ring_base)
				dma_free_coherent(NULL,
						  (fpi->tx_ring +
						   fpi->rx_ring) *
						  sizeof(cbd_t), fep->ring_base,
						  fep->ring_mem_addr);
		}
		free_netdev(dev);
	}
	return err;
}

int fec_8xx_cleanup_one(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	fec_t *fecp = fep->fecp;
	const struct fec_platform_info *fpi = fep->fpi;

	fec_whack_reset(fecp);

	unregister_netdev(dev);

	dma_free_coherent(NULL, (fpi->tx_ring + fpi->rx_ring) * sizeof(cbd_t),
			  fep->ring_base, fep->ring_mem_addr);

	free_netdev(dev);

	return 0;
}

/**************************************************************************************/
/**************************************************************************************/
/**************************************************************************************/

static int __init fec_8xx_init(void)
{
	return fec_8xx_platform_init();
}

static void __exit fec_8xx_cleanup(void)
{
	fec_8xx_platform_cleanup();
}

/**************************************************************************************/
/**************************************************************************************/
/**************************************************************************************/

module_init(fec_8xx_init);
module_exit(fec_8xx_cleanup);