summaryrefslogtreecommitdiff
path: root/drivers/rapidio/rio-scan.c
blob: 913950212605ddfdc5c6985bae4b8ee64bba76ba (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
/*
 * RapidIO enumeration and discovery support
 *
 * Copyright 2005 MontaVista Software, Inc.
 * Matt Porter <mporter@kernel.crashing.org>
 *
 * Copyright 2009 Integrated Device Technology, Inc.
 * Alex Bounine <alexandre.bounine@idt.com>
 * - Added Port-Write/Error Management initialization and handling
 *
 * Copyright 2009 Sysgo AG
 * Thomas Moll <thomas.moll@sysgo.com>
 * - Added Input- Output- enable functionality, to allow full communication
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/types.h>
#include <linux/kernel.h>

#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/rio.h>
#include <linux/rio_drv.h>
#include <linux/rio_ids.h>
#include <linux/rio_regs.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/jiffies.h>
#include <linux/slab.h>

#include "rio.h"

static void rio_init_em(struct rio_dev *rdev);

static int next_destid = 0;
static int next_comptag = 1;

static int rio_mport_phys_table[] = {
	RIO_EFB_PAR_EP_ID,
	RIO_EFB_PAR_EP_REC_ID,
	RIO_EFB_SER_EP_ID,
	RIO_EFB_SER_EP_REC_ID,
	-1,
};


/**
 * rio_destid_alloc - Allocate next available destID for given network
 * @net: RIO network
 *
 * Returns next available device destination ID for the specified RIO network.
 * Marks allocated ID as one in use.
 * Returns RIO_INVALID_DESTID if new destID is not available.
 */
static u16 rio_destid_alloc(struct rio_net *net)
{
	int destid;
	struct rio_id_table *idtab = &net->destid_table;

	spin_lock(&idtab->lock);
	destid = find_first_zero_bit(idtab->table, idtab->max);

	if (destid < idtab->max) {
		set_bit(destid, idtab->table);
		destid += idtab->start;
	} else
		destid = RIO_INVALID_DESTID;

	spin_unlock(&idtab->lock);
	return (u16)destid;
}

/**
 * rio_destid_reserve - Reserve the specivied destID
 * @net: RIO network
 * @destid: destID to reserve
 *
 * Tries to reserve the specified destID.
 * Returns 0 if successfull.
 */
static int rio_destid_reserve(struct rio_net *net, u16 destid)
{
	int oldbit;
	struct rio_id_table *idtab = &net->destid_table;

	destid -= idtab->start;
	spin_lock(&idtab->lock);
	oldbit = test_and_set_bit(destid, idtab->table);
	spin_unlock(&idtab->lock);
	return oldbit;
}

/**
 * rio_destid_free - free a previously allocated destID
 * @net: RIO network
 * @destid: destID to free
 *
 * Makes the specified destID available for use.
 */
static void rio_destid_free(struct rio_net *net, u16 destid)
{
	struct rio_id_table *idtab = &net->destid_table;

	destid -= idtab->start;
	spin_lock(&idtab->lock);
	clear_bit(destid, idtab->table);
	spin_unlock(&idtab->lock);
}

/**
 * rio_destid_first - return first destID in use
 * @net: RIO network
 */
static u16 rio_destid_first(struct rio_net *net)
{
	int destid;
	struct rio_id_table *idtab = &net->destid_table;

	spin_lock(&idtab->lock);
	destid = find_first_bit(idtab->table, idtab->max);
	if (destid >= idtab->max)
		destid = RIO_INVALID_DESTID;
	else
		destid += idtab->start;
	spin_unlock(&idtab->lock);
	return (u16)destid;
}

/**
 * rio_destid_next - return next destID in use
 * @net: RIO network
 * @from: destination ID from which search shall continue
 */
static u16 rio_destid_next(struct rio_net *net, u16 from)
{
	int destid;
	struct rio_id_table *idtab = &net->destid_table;

	spin_lock(&idtab->lock);
	destid = find_next_bit(idtab->table, idtab->max, from);
	if (destid >= idtab->max)
		destid = RIO_INVALID_DESTID;
	else
		destid += idtab->start;
	spin_unlock(&idtab->lock);
	return (u16)destid;
}

/**
 * rio_get_device_id - Get the base/extended device id for a device
 * @port: RIO master port
 * @destid: Destination ID of device
 * @hopcount: Hopcount to device
 *
 * Reads the base/extended device id from a device. Returns the
 * 8/16-bit device ID.
 */
static u16 rio_get_device_id(struct rio_mport *port, u16 destid, u8 hopcount)
{
	u32 result;

	rio_mport_read_config_32(port, destid, hopcount, RIO_DID_CSR, &result);

	return RIO_GET_DID(port->sys_size, result);
}

/**
 * rio_set_device_id - Set the base/extended device id for a device
 * @port: RIO master port
 * @destid: Destination ID of device
 * @hopcount: Hopcount to device
 * @did: Device ID value to be written
 *
 * Writes the base/extended device id from a device.
 */
static void rio_set_device_id(struct rio_mport *port, u16 destid, u8 hopcount, u16 did)
{
	rio_mport_write_config_32(port, destid, hopcount, RIO_DID_CSR,
				  RIO_SET_DID(port->sys_size, did));
}

/**
 * rio_local_set_device_id - Set the base/extended device id for a port
 * @port: RIO master port
 * @did: Device ID value to be written
 *
 * Writes the base/extended device id from a device.
 */
static void rio_local_set_device_id(struct rio_mport *port, u16 did)
{
	rio_local_write_config_32(port, RIO_DID_CSR, RIO_SET_DID(port->sys_size,
				did));
}

/**
 * rio_clear_locks- Release all host locks and signal enumeration complete
 * @net: RIO network to run on
 *
 * Marks the component tag CSR on each device with the enumeration
 * complete flag. When complete, it then release the host locks on
 * each device. Returns 0 on success or %-EINVAL on failure.
 */
static int rio_clear_locks(struct rio_net *net)
{
	struct rio_mport *port = net->hport;
	struct rio_dev *rdev;
	u32 result;
	int ret = 0;

	/* Release host device id locks */
	rio_local_write_config_32(port, RIO_HOST_DID_LOCK_CSR,
				  port->host_deviceid);
	rio_local_read_config_32(port, RIO_HOST_DID_LOCK_CSR, &result);
	if ((result & 0xffff) != 0xffff) {
		printk(KERN_INFO
		       "RIO: badness when releasing host lock on master port, result %8.8x\n",
		       result);
		ret = -EINVAL;
	}
	list_for_each_entry(rdev, &net->devices, net_list) {
		rio_write_config_32(rdev, RIO_HOST_DID_LOCK_CSR,
				    port->host_deviceid);
		rio_read_config_32(rdev, RIO_HOST_DID_LOCK_CSR, &result);
		if ((result & 0xffff) != 0xffff) {
			printk(KERN_INFO
			       "RIO: badness when releasing host lock on vid %4.4x did %4.4x\n",
			       rdev->vid, rdev->did);
			ret = -EINVAL;
		}

		/* Mark device as discovered and enable master */
		rio_read_config_32(rdev,
				   rdev->phys_efptr + RIO_PORT_GEN_CTL_CSR,
				   &result);
		result |= RIO_PORT_GEN_DISCOVERED | RIO_PORT_GEN_MASTER;
		rio_write_config_32(rdev,
				    rdev->phys_efptr + RIO_PORT_GEN_CTL_CSR,
				    result);
	}

	return ret;
}

/**
 * rio_enum_host- Set host lock and initialize host destination ID
 * @port: Master port to issue transaction
 *
 * Sets the local host master port lock and destination ID register
 * with the host device ID value. The host device ID value is provided
 * by the platform. Returns %0 on success or %-1 on failure.
 */
static int rio_enum_host(struct rio_mport *port)
{
	u32 result;

	/* Set master port host device id lock */
	rio_local_write_config_32(port, RIO_HOST_DID_LOCK_CSR,
				  port->host_deviceid);

	rio_local_read_config_32(port, RIO_HOST_DID_LOCK_CSR, &result);
	if ((result & 0xffff) != port->host_deviceid)
		return -1;

	/* Set master port destid and init destid ctr */
	rio_local_set_device_id(port, port->host_deviceid);
	return 0;
}

/**
 * rio_device_has_destid- Test if a device contains a destination ID register
 * @port: Master port to issue transaction
 * @src_ops: RIO device source operations
 * @dst_ops: RIO device destination operations
 *
 * Checks the provided @src_ops and @dst_ops for the necessary transaction
 * capabilities that indicate whether or not a device will implement a
 * destination ID register. Returns 1 if true or 0 if false.
 */
static int rio_device_has_destid(struct rio_mport *port, int src_ops,
				 int dst_ops)
{
	u32 mask = RIO_OPS_READ | RIO_OPS_WRITE | RIO_OPS_ATOMIC_TST_SWP | RIO_OPS_ATOMIC_INC | RIO_OPS_ATOMIC_DEC | RIO_OPS_ATOMIC_SET | RIO_OPS_ATOMIC_CLR;

	return !!((src_ops | dst_ops) & mask);
}

/**
 * rio_release_dev- Frees a RIO device struct
 * @dev: LDM device associated with a RIO device struct
 *
 * Gets the RIO device struct associated a RIO device struct.
 * The RIO device struct is freed.
 */
static void rio_release_dev(struct device *dev)
{
	struct rio_dev *rdev;

	rdev = to_rio_dev(dev);
	kfree(rdev);
}

/**
 * rio_is_switch- Tests if a RIO device has switch capabilities
 * @rdev: RIO device
 *
 * Gets the RIO device Processing Element Features register
 * contents and tests for switch capabilities. Returns 1 if
 * the device is a switch or 0 if it is not a switch.
 * The RIO device struct is freed.
 */
static int rio_is_switch(struct rio_dev *rdev)
{
	if (rdev->pef & RIO_PEF_SWITCH)
		return 1;
	return 0;
}

/**
 * rio_setup_device- Allocates and sets up a RIO device
 * @net: RIO network
 * @port: Master port to send transactions
 * @destid: Current destination ID
 * @hopcount: Current hopcount
 * @do_enum: Enumeration/Discovery mode flag
 *
 * Allocates a RIO device and configures fields based on configuration
 * space contents. If device has a destination ID register, a destination
 * ID is either assigned in enumeration mode or read from configuration
 * space in discovery mode.  If the device has switch capabilities, then
 * a switch is allocated and configured appropriately. Returns a pointer
 * to a RIO device on success or NULL on failure.
 *
 */
static struct rio_dev *rio_setup_device(struct rio_net *net,
					struct rio_mport *port, u16 destid,
					u8 hopcount, int do_enum)
{
	int ret = 0;
	struct rio_dev *rdev;
	struct rio_switch *rswitch = NULL;
	int result, rdid;
	size_t size;
	u32 swpinfo = 0;

	size = sizeof(struct rio_dev);
	if (rio_mport_read_config_32(port, destid, hopcount,
				     RIO_PEF_CAR, &result))
		return NULL;

	if (result & (RIO_PEF_SWITCH | RIO_PEF_MULTIPORT)) {
		rio_mport_read_config_32(port, destid, hopcount,
					 RIO_SWP_INFO_CAR, &swpinfo);
		if (result & RIO_PEF_SWITCH) {
			size += (RIO_GET_TOTAL_PORTS(swpinfo) *
				sizeof(rswitch->nextdev[0])) + sizeof(*rswitch);
		}
	}

	rdev = kzalloc(size, GFP_KERNEL);
	if (!rdev)
		return NULL;

	rdev->net = net;
	rdev->pef = result;
	rdev->swpinfo = swpinfo;
	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_ID_CAR,
				 &result);
	rdev->did = result >> 16;
	rdev->vid = result & 0xffff;
	rio_mport_read_config_32(port, destid, hopcount, RIO_DEV_INFO_CAR,
				 &rdev->device_rev);
	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_ID_CAR,
				 &result);
	rdev->asm_did = result >> 16;
	rdev->asm_vid = result & 0xffff;
	rio_mport_read_config_32(port, destid, hopcount, RIO_ASM_INFO_CAR,
				 &result);
	rdev->asm_rev = result >> 16;
	if (rdev->pef & RIO_PEF_EXT_FEATURES) {
		rdev->efptr = result & 0xffff;
		rdev->phys_efptr = rio_mport_get_physefb(port, 0, destid,
							 hopcount);

		rdev->em_efptr = rio_mport_get_feature(port, 0, destid,
						hopcount, RIO_EFB_ERR_MGMNT);
	}

	rio_mport_read_config_32(port, destid, hopcount, RIO_SRC_OPS_CAR,
				 &rdev->src_ops);
	rio_mport_read_config_32(port, destid, hopcount, RIO_DST_OPS_CAR,
				 &rdev->dst_ops);

	if (do_enum) {
		/* Assign component tag to device */
		if (next_comptag >= 0x10000) {
			pr_err("RIO: Component Tag Counter Overflow\n");
			goto cleanup;
		}
		rio_mport_write_config_32(port, destid, hopcount,
					  RIO_COMPONENT_TAG_CSR, next_comptag);
		rdev->comp_tag = next_comptag++;
		rdev->do_enum = true;
	}  else {
		rio_mport_read_config_32(port, destid, hopcount,
					 RIO_COMPONENT_TAG_CSR,
					 &rdev->comp_tag);
	}

	if (rio_device_has_destid(port, rdev->src_ops, rdev->dst_ops)) {
		if (do_enum) {
			rio_set_device_id(port, destid, hopcount, next_destid);
			rdev->destid = next_destid;
			next_destid = rio_destid_alloc(net);
		} else
			rdev->destid = rio_get_device_id(port, destid, hopcount);

		rdev->hopcount = 0xff;
	} else {
		/* Switch device has an associated destID which
		 * will be adjusted later
		 */
		rdev->destid = destid;
		rdev->hopcount = hopcount;
	}

	/* If a PE has both switch and other functions, show it as a switch */
	if (rio_is_switch(rdev)) {
		rswitch = rdev->rswitch;
		rswitch->switchid = rdev->comp_tag & RIO_CTAG_UDEVID;
		rswitch->port_ok = 0;
		spin_lock_init(&rswitch->lock);
		rswitch->route_table = kzalloc(sizeof(u8)*
					RIO_MAX_ROUTE_ENTRIES(port->sys_size),
					GFP_KERNEL);
		if (!rswitch->route_table)
			goto cleanup;
		/* Initialize switch route table */
		for (rdid = 0; rdid < RIO_MAX_ROUTE_ENTRIES(port->sys_size);
				rdid++)
			rswitch->route_table[rdid] = RIO_INVALID_ROUTE;
		dev_set_name(&rdev->dev, "%02x:s:%04x", rdev->net->id,
			     rswitch->switchid);

		if (do_enum)
			rio_route_clr_table(rdev, RIO_GLOBAL_TABLE, 0);

		list_add_tail(&rswitch->node, &net->switches);

	} else {
		if (do_enum)
			/*Enable Input Output Port (transmitter reviever)*/
			rio_enable_rx_tx_port(port, 0, destid, hopcount, 0);

		dev_set_name(&rdev->dev, "%02x:e:%04x", rdev->net->id,
			     rdev->destid);
	}

	rio_attach_device(rdev);

	device_initialize(&rdev->dev);
	rdev->dev.release = rio_release_dev;
	rio_dev_get(rdev);

	rdev->dma_mask = DMA_BIT_MASK(32);
	rdev->dev.dma_mask = &rdev->dma_mask;
	rdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);

	if (rdev->dst_ops & RIO_DST_OPS_DOORBELL)
		rio_init_dbell_res(&rdev->riores[RIO_DOORBELL_RESOURCE],
				   0, 0xffff);

	ret = rio_add_device(rdev);
	if (ret)
		goto cleanup;

	return rdev;

cleanup:
	if (rswitch)
		kfree(rswitch->route_table);

	kfree(rdev);
	return NULL;
}

/**
 * rio_sport_is_active- Tests if a switch port has an active connection.
 * @port: Master port to send transaction
 * @destid: Associated destination ID for switch
 * @hopcount: Hopcount to reach switch
 * @sport: Switch port number
 *
 * Reads the port error status CSR for a particular switch port to
 * determine if the port has an active link.  Returns
 * %RIO_PORT_N_ERR_STS_PORT_OK if the port is active or %0 if it is
 * inactive.
 */
static int
rio_sport_is_active(struct rio_mport *port, u16 destid, u8 hopcount, int sport)
{
	u32 result = 0;
	u32 ext_ftr_ptr;

	ext_ftr_ptr = rio_mport_get_efb(port, 0, destid, hopcount, 0);

	while (ext_ftr_ptr) {
		rio_mport_read_config_32(port, destid, hopcount,
					 ext_ftr_ptr, &result);
		result = RIO_GET_BLOCK_ID(result);
		if ((result == RIO_EFB_SER_EP_FREE_ID) ||
		    (result == RIO_EFB_SER_EP_FREE_ID_V13P) ||
		    (result == RIO_EFB_SER_EP_FREC_ID))
			break;

		ext_ftr_ptr = rio_mport_get_efb(port, 0, destid, hopcount,
						ext_ftr_ptr);
	}

	if (ext_ftr_ptr)
		rio_mport_read_config_32(port, destid, hopcount,
					 ext_ftr_ptr +
					 RIO_PORT_N_ERR_STS_CSR(sport),
					 &result);

	return result & RIO_PORT_N_ERR_STS_PORT_OK;
}

/**
 * rio_get_host_deviceid_lock- Reads the Host Device ID Lock CSR on a device
 * @port: Master port to send transaction
 * @hopcount: Number of hops to the device
 *
 * Used during enumeration to read the Host Device ID Lock CSR on a
 * RIO device. Returns the value of the lock register.
 */
static u16 rio_get_host_deviceid_lock(struct rio_mport *port, u8 hopcount)
{
	u32 result;

	rio_mport_read_config_32(port, RIO_ANY_DESTID(port->sys_size), hopcount,
				 RIO_HOST_DID_LOCK_CSR, &result);

	return (u16) (result & 0xffff);
}

/**
 * rio_enum_peer- Recursively enumerate a RIO network through a master port
 * @net: RIO network being enumerated
 * @port: Master port to send transactions
 * @hopcount: Number of hops into the network
 * @prev: Previous RIO device connected to the enumerated one
 * @prev_port: Port on previous RIO device
 *
 * Recursively enumerates a RIO network.  Transactions are sent via the
 * master port passed in @port.
 */
static int rio_enum_peer(struct rio_net *net, struct rio_mport *port,
			 u8 hopcount, struct rio_dev *prev, int prev_port)
{
	struct rio_dev *rdev;
	u32 regval;
	int tmp;

	if (rio_mport_chk_dev_access(port,
			RIO_ANY_DESTID(port->sys_size), hopcount)) {
		pr_debug("RIO: device access check failed\n");
		return -1;
	}

	if (rio_get_host_deviceid_lock(port, hopcount) == port->host_deviceid) {
		pr_debug("RIO: PE already discovered by this host\n");
		/*
		 * Already discovered by this host. Add it as another
		 * link to the existing device.
		 */
		rio_mport_read_config_32(port, RIO_ANY_DESTID(port->sys_size),
				hopcount, RIO_COMPONENT_TAG_CSR, &regval);

		if (regval) {
			rdev = rio_get_comptag((regval & 0xffff), NULL);

			if (rdev && prev && rio_is_switch(prev)) {
				pr_debug("RIO: redundant path to %s\n",
					 rio_name(rdev));
				prev->rswitch->nextdev[prev_port] = rdev;
			}
		}

		return 0;
	}

	/* Attempt to acquire device lock */
	rio_mport_write_config_32(port, RIO_ANY_DESTID(port->sys_size),
				  hopcount,
				  RIO_HOST_DID_LOCK_CSR, port->host_deviceid);
	while ((tmp = rio_get_host_deviceid_lock(port, hopcount))
	       < port->host_deviceid) {
		/* Delay a bit */
		mdelay(1);
		/* Attempt to acquire device lock again */
		rio_mport_write_config_32(port, RIO_ANY_DESTID(port->sys_size),
					  hopcount,
					  RIO_HOST_DID_LOCK_CSR,
					  port->host_deviceid);
	}

	if (rio_get_host_deviceid_lock(port, hopcount) > port->host_deviceid) {
		pr_debug(
		    "RIO: PE locked by a higher priority host...retreating\n");
		return -1;
	}

	/* Setup new RIO device */
	rdev = rio_setup_device(net, port, RIO_ANY_DESTID(port->sys_size),
					hopcount, 1);
	if (rdev) {
		/* Add device to the global and bus/net specific list. */
		list_add_tail(&rdev->net_list, &net->devices);
		rdev->prev = prev;
		if (prev && rio_is_switch(prev))
			prev->rswitch->nextdev[prev_port] = rdev;
	} else
		return -1;

	if (rio_is_switch(rdev)) {
		int sw_destid;
		int cur_destid;
		int sw_inport;
		u16 destid;
		int port_num;

		sw_inport = RIO_GET_PORT_NUM(rdev->swpinfo);
		rio_route_add_entry(rdev, RIO_GLOBAL_TABLE,
				    port->host_deviceid, sw_inport, 0);
		rdev->rswitch->route_table[port->host_deviceid] = sw_inport;

		destid = rio_destid_first(net);
		while (destid != RIO_INVALID_DESTID && destid < next_destid) {
			if (destid != port->host_deviceid) {
				rio_route_add_entry(rdev, RIO_GLOBAL_TABLE,
						    destid, sw_inport, 0);
				rdev->rswitch->route_table[destid] = sw_inport;
			}
			destid = rio_destid_next(net, destid + 1);
		}
		pr_debug(
		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
		    rio_name(rdev), rdev->vid, rdev->did,
		    RIO_GET_TOTAL_PORTS(rdev->swpinfo));
		sw_destid = next_destid;
		for (port_num = 0;
		     port_num < RIO_GET_TOTAL_PORTS(rdev->swpinfo);
		     port_num++) {
			if (sw_inport == port_num) {
				rio_enable_rx_tx_port(port, 0,
					      RIO_ANY_DESTID(port->sys_size),
					      hopcount, port_num);
				rdev->rswitch->port_ok |= (1 << port_num);
				continue;
			}

			cur_destid = next_destid;

			if (rio_sport_is_active
			    (port, RIO_ANY_DESTID(port->sys_size), hopcount,
			     port_num)) {
				pr_debug(
				    "RIO: scanning device on port %d\n",
				    port_num);
				rio_enable_rx_tx_port(port, 0,
					      RIO_ANY_DESTID(port->sys_size),
					      hopcount, port_num);
				rdev->rswitch->port_ok |= (1 << port_num);
				rio_route_add_entry(rdev, RIO_GLOBAL_TABLE,
						RIO_ANY_DESTID(port->sys_size),
						port_num, 0);

				if (rio_enum_peer(net, port, hopcount + 1,
						  rdev, port_num) < 0)
					return -1;

				/* Update routing tables */
				destid = rio_destid_next(net, cur_destid + 1);
				if (destid != RIO_INVALID_DESTID) {
					for (destid = cur_destid;
					     destid < next_destid;) {
						if (destid != port->host_deviceid) {
							rio_route_add_entry(rdev,
								    RIO_GLOBAL_TABLE,
								    destid,
								    port_num,
								    0);
							rdev->rswitch->
								route_table[destid] =
								port_num;
						}
						destid = rio_destid_next(net,
								destid + 1);
					}
				}
			} else {
				/* If switch supports Error Management,
				 * set PORT_LOCKOUT bit for unused port
				 */
				if (rdev->em_efptr)
					rio_set_port_lockout(rdev, port_num, 1);

				rdev->rswitch->port_ok &= ~(1 << port_num);
			}
		}

		/* Direct Port-write messages to the enumeratiing host */
		if ((rdev->src_ops & RIO_SRC_OPS_PORT_WRITE) &&
		    (rdev->em_efptr)) {
			rio_write_config_32(rdev,
					rdev->em_efptr + RIO_EM_PW_TGT_DEVID,
					(port->host_deviceid << 16) |
					(port->sys_size << 15));
		}

		rio_init_em(rdev);

		/* Check for empty switch */
		if (next_destid == sw_destid)
			next_destid = rio_destid_alloc(net);

		rdev->destid = sw_destid;
	} else
		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
		    rio_name(rdev), rdev->vid, rdev->did);

	return 0;
}

/**
 * rio_enum_complete- Tests if enumeration of a network is complete
 * @port: Master port to send transaction
 *
 * Tests the PGCCSR discovered bit for non-zero value (enumeration
 * complete flag). Return %1 if enumeration is complete or %0 if
 * enumeration is incomplete.
 */
static int rio_enum_complete(struct rio_mport *port)
{
	u32 regval;

	rio_local_read_config_32(port, port->phys_efptr + RIO_PORT_GEN_CTL_CSR,
				 &regval);
	return (regval & RIO_PORT_GEN_DISCOVERED) ? 1 : 0;
}

/**
 * rio_disc_peer- Recursively discovers a RIO network through a master port
 * @net: RIO network being discovered
 * @port: Master port to send transactions
 * @destid: Current destination ID in network
 * @hopcount: Number of hops into the network
 * @prev: previous rio_dev
 * @prev_port: previous port number
 *
 * Recursively discovers a RIO network.  Transactions are sent via the
 * master port passed in @port.
 */
static int
rio_disc_peer(struct rio_net *net, struct rio_mport *port, u16 destid,
	      u8 hopcount, struct rio_dev *prev, int prev_port)
{
	u8 port_num, route_port;
	struct rio_dev *rdev;
	u16 ndestid;

	/* Setup new RIO device */
	if ((rdev = rio_setup_device(net, port, destid, hopcount, 0))) {
		/* Add device to the global and bus/net specific list. */
		list_add_tail(&rdev->net_list, &net->devices);
		rdev->prev = prev;
		if (prev && rio_is_switch(prev))
			prev->rswitch->nextdev[prev_port] = rdev;
	} else
		return -1;

	if (rio_is_switch(rdev)) {
		/* Associated destid is how we accessed this switch */
		rdev->destid = destid;

		pr_debug(
		    "RIO: found %s (vid %4.4x did %4.4x) with %d ports\n",
		    rio_name(rdev), rdev->vid, rdev->did,
		    RIO_GET_TOTAL_PORTS(rdev->swpinfo));
		for (port_num = 0;
		     port_num < RIO_GET_TOTAL_PORTS(rdev->swpinfo);
		     port_num++) {
			if (RIO_GET_PORT_NUM(rdev->swpinfo) == port_num)
				continue;

			if (rio_sport_is_active
			    (port, destid, hopcount, port_num)) {
				pr_debug(
				    "RIO: scanning device on port %d\n",
				    port_num);

				rio_lock_device(port, destid, hopcount, 1000);

				for (ndestid = 0;
				     ndestid < RIO_ANY_DESTID(port->sys_size);
				     ndestid++) {
					rio_route_get_entry(rdev,
							    RIO_GLOBAL_TABLE,
							    ndestid,
							    &route_port, 0);
					if (route_port == port_num)
						break;
				}

				if (ndestid == RIO_ANY_DESTID(port->sys_size))
					continue;
				rio_unlock_device(port, destid, hopcount);
				if (rio_disc_peer(net, port, ndestid,
					hopcount + 1, rdev, port_num) < 0)
					return -1;
			}
		}
	} else
		pr_debug("RIO: found %s (vid %4.4x did %4.4x)\n",
		    rio_name(rdev), rdev->vid, rdev->did);

	return 0;
}

/**
 * rio_mport_is_active- Tests if master port link is active
 * @port: Master port to test
 *
 * Reads the port error status CSR for the master port to
 * determine if the port has an active link.  Returns
 * %RIO_PORT_N_ERR_STS_PORT_OK if the  master port is active
 * or %0 if it is inactive.
 */
static int rio_mport_is_active(struct rio_mport *port)
{
	u32 result = 0;
	u32 ext_ftr_ptr;
	int *entry = rio_mport_phys_table;

	do {
		if ((ext_ftr_ptr =
		     rio_mport_get_feature(port, 1, 0, 0, *entry)))
			break;
	} while (*++entry >= 0);

	if (ext_ftr_ptr)
		rio_local_read_config_32(port,
					 ext_ftr_ptr +
					 RIO_PORT_N_ERR_STS_CSR(port->index),
					 &result);

	return result & RIO_PORT_N_ERR_STS_PORT_OK;
}

/**
 * rio_alloc_net- Allocate and configure a new RIO network
 * @port: Master port associated with the RIO network
 * @do_enum: Enumeration/Discovery mode flag
 * @start: logical minimal start id for new net
 *
 * Allocates a RIO network structure, initializes per-network
 * list heads, and adds the associated master port to the
 * network list of associated master ports. Returns a
 * RIO network pointer on success or %NULL on failure.
 */
static struct rio_net *rio_alloc_net(struct rio_mport *port,
					       int do_enum, u16 start)
{
	struct rio_net *net;

	net = kzalloc(sizeof(struct rio_net), GFP_KERNEL);
	if (net && do_enum) {
		net->destid_table.table = kcalloc(
			BITS_TO_LONGS(RIO_MAX_ROUTE_ENTRIES(port->sys_size)),
			sizeof(long),
			GFP_KERNEL);

		if (net->destid_table.table == NULL) {
			pr_err("RIO: failed to allocate destID table\n");
			kfree(net);
			net = NULL;
		} else {
			net->destid_table.start = start;
			net->destid_table.max =
					RIO_MAX_ROUTE_ENTRIES(port->sys_size);
			spin_lock_init(&net->destid_table.lock);
		}
	}

	if (net) {
		INIT_LIST_HEAD(&net->node);
		INIT_LIST_HEAD(&net->devices);
		INIT_LIST_HEAD(&net->switches);
		INIT_LIST_HEAD(&net->mports);
		list_add_tail(&port->nnode, &net->mports);
		net->hport = port;
		net->id = port->id;
	}
	return net;
}

/**
 * rio_update_route_tables- Updates route tables in switches
 * @net: RIO network to run update on
 *
 * For each enumerated device, ensure that each switch in a system
 * has correct routing entries. Add routes for devices that where
 * unknown dirung the first enumeration pass through the switch.
 */
static void rio_update_route_tables(struct rio_net *net)
{
	struct rio_dev *rdev, *swrdev;
	struct rio_switch *rswitch;
	u8 sport;
	u16 destid;

	list_for_each_entry(rdev, &net->devices, net_list) {

		destid = rdev->destid;

		list_for_each_entry(rswitch, &net->switches, node) {

			if (rio_is_switch(rdev)	&& (rdev->rswitch == rswitch))
				continue;

			if (RIO_INVALID_ROUTE == rswitch->route_table[destid]) {
				swrdev = sw_to_rio_dev(rswitch);

				/* Skip if destid ends in empty switch*/
				if (swrdev->destid == destid)
					continue;

				sport = RIO_GET_PORT_NUM(swrdev->swpinfo);

				rio_route_add_entry(swrdev, RIO_GLOBAL_TABLE,
						    destid, sport, 0);
				rswitch->route_table[destid] = sport;
			}
		}
	}
}

/**
 * rio_init_em - Initializes RIO Error Management (for switches)
 * @rdev: RIO device
 *
 * For each enumerated switch, call device-specific error management
 * initialization routine (if supplied by the switch driver).
 */
static void rio_init_em(struct rio_dev *rdev)
{
	if (rio_is_switch(rdev) && (rdev->em_efptr) &&
	    rdev->rswitch->ops && rdev->rswitch->ops->em_init) {
		rdev->rswitch->ops->em_init(rdev);
	}
}

/**
 * rio_pw_enable - Enables/disables port-write handling by a master port
 * @port: Master port associated with port-write handling
 * @enable:  1=enable,  0=disable
 */
static void rio_pw_enable(struct rio_mport *port, int enable)
{
	if (port->ops->pwenable)
		port->ops->pwenable(port, enable);
}

/**
 * rio_enum_mport- Start enumeration through a master port
 * @mport: Master port to send transactions
 * @flags: Enumeration control flags
 *
 * Starts the enumeration process. If somebody has enumerated our
 * master port device, then give up. If not and we have an active
 * link, then start recursive peer enumeration. Returns %0 if
 * enumeration succeeds or %-EBUSY if enumeration fails.
 */
static int rio_enum_mport(struct rio_mport *mport, u32 flags)
{
	struct rio_net *net = NULL;
	int rc = 0;

	printk(KERN_INFO "RIO: enumerate master port %d, %s\n", mport->id,
	       mport->name);

	/*
	 * To avoid multiple start requests (repeat enumeration is not supported
	 * by this method) check if enumeration/discovery was performed for this
	 * mport: if mport was added into the list of mports for a net exit
	 * with error.
	 */
	if (mport->nnode.next || mport->nnode.prev)
		return -EBUSY;

	/* If somebody else enumerated our master port device, bail. */
	if (rio_enum_host(mport) < 0) {
		printk(KERN_INFO
		       "RIO: master port %d device has been enumerated by a remote host\n",
		       mport->id);
		rc = -EBUSY;
		goto out;
	}

	/* If master port has an active link, allocate net and enum peers */
	if (rio_mport_is_active(mport)) {
		net = rio_alloc_net(mport, 1, 0);
		if (!net) {
			printk(KERN_ERR "RIO: failed to allocate new net\n");
			rc = -ENOMEM;
			goto out;
		}

		/* reserve mport destID in new net */
		rio_destid_reserve(net, mport->host_deviceid);

		/* Enable Input Output Port (transmitter reviever) */
		rio_enable_rx_tx_port(mport, 1, 0, 0, 0);

		/* Set component tag for host */
		rio_local_write_config_32(mport, RIO_COMPONENT_TAG_CSR,
					  next_comptag++);

		next_destid = rio_destid_alloc(net);

		if (rio_enum_peer(net, mport, 0, NULL, 0) < 0) {
			/* A higher priority host won enumeration, bail. */
			printk(KERN_INFO
			       "RIO: master port %d device has lost enumeration to a remote host\n",
			       mport->id);
			rio_clear_locks(net);
			rc = -EBUSY;
			goto out;
		}
		/* free the last allocated destID (unused) */
		rio_destid_free(net, next_destid);
		rio_update_route_tables(net);
		rio_clear_locks(net);
		rio_pw_enable(mport, 1);
	} else {
		printk(KERN_INFO "RIO: master port %d link inactive\n",
		       mport->id);
		rc = -EINVAL;
	}

      out:
	return rc;
}

/**
 * rio_build_route_tables- Generate route tables from switch route entries
 * @net: RIO network to run route tables scan on
 *
 * For each switch device, generate a route table by copying existing
 * route entries from the switch.
 */
static void rio_build_route_tables(struct rio_net *net)
{
	struct rio_switch *rswitch;
	struct rio_dev *rdev;
	int i;
	u8 sport;

	list_for_each_entry(rswitch, &net->switches, node) {
		rdev = sw_to_rio_dev(rswitch);

		rio_lock_device(net->hport, rdev->destid,
				rdev->hopcount, 1000);
		for (i = 0;
		     i < RIO_MAX_ROUTE_ENTRIES(net->hport->sys_size);
		     i++) {
			if (rio_route_get_entry(rdev, RIO_GLOBAL_TABLE,
						i, &sport, 0) < 0)
				continue;
			rswitch->route_table[i] = sport;
		}

		rio_unlock_device(net->hport, rdev->destid, rdev->hopcount);
	}
}

/**
 * rio_disc_mport- Start discovery through a master port
 * @mport: Master port to send transactions
 * @flags: discovery control flags
 *
 * Starts the discovery process. If we have an active link,
 * then wait for the signal that enumeration is complete (if wait
 * is allowed).
 * When enumeration completion is signaled, start recursive
 * peer discovery. Returns %0 if discovery succeeds or %-EBUSY
 * on failure.
 */
static int rio_disc_mport(struct rio_mport *mport, u32 flags)
{
	struct rio_net *net = NULL;
	unsigned long to_end;

	printk(KERN_INFO "RIO: discover master port %d, %s\n", mport->id,
	       mport->name);

	/* If master port has an active link, allocate net and discover peers */
	if (rio_mport_is_active(mport)) {
		if (rio_enum_complete(mport))
			goto enum_done;
		else if (flags & RIO_SCAN_ENUM_NO_WAIT)
			return -EAGAIN;

		pr_debug("RIO: wait for enumeration to complete...\n");

		to_end = jiffies + CONFIG_RAPIDIO_DISC_TIMEOUT * HZ;
		while (time_before(jiffies, to_end)) {
			if (rio_enum_complete(mport))
				goto enum_done;
			msleep(10);
		}

		pr_debug("RIO: discovery timeout on mport %d %s\n",
			 mport->id, mport->name);
		goto bail;
enum_done:
		pr_debug("RIO: ... enumeration done\n");

		net = rio_alloc_net(mport, 0, 0);
		if (!net) {
			printk(KERN_ERR "RIO: Failed to allocate new net\n");
			goto bail;
		}

		/* Read DestID assigned by enumerator */
		rio_local_read_config_32(mport, RIO_DID_CSR,
					 &mport->host_deviceid);
		mport->host_deviceid = RIO_GET_DID(mport->sys_size,
						   mport->host_deviceid);

		if (rio_disc_peer(net, mport, RIO_ANY_DESTID(mport->sys_size),
					0, NULL, 0) < 0) {
			printk(KERN_INFO
			       "RIO: master port %d device has failed discovery\n",
			       mport->id);
			goto bail;
		}

		rio_build_route_tables(net);
	}

	return 0;
bail:
	return -EBUSY;
}

static struct rio_scan rio_scan_ops = {
	.enumerate = rio_enum_mport,
	.discover = rio_disc_mport,
};

static bool scan;
module_param(scan, bool, 0);
MODULE_PARM_DESC(scan, "Start RapidIO network enumeration/discovery "
			"(default = 0)");

/**
 * rio_basic_attach:
 *
 * When this enumeration/discovery method is loaded as a module this function
 * registers its specific enumeration and discover routines for all available
 * RapidIO mport devices. The "scan" command line parameter controls ability of
 * the module to start RapidIO enumeration/discovery automatically.
 *
 * Returns 0 for success or -EIO if unable to register itself.
 *
 * This enumeration/discovery method cannot be unloaded and therefore does not
 * provide a matching cleanup_module routine.
 */

static int __init rio_basic_attach(void)
{
	if (rio_register_scan(RIO_MPORT_ANY, &rio_scan_ops))
		return -EIO;
	if (scan)
		rio_init_mports();
	return 0;
}

late_initcall(rio_basic_attach);

MODULE_DESCRIPTION("Basic RapidIO enumeration/discovery");
MODULE_LICENSE("GPL");