summaryrefslogtreecommitdiff
path: root/drivers/ntb/test/ntb_perf.c
blob: 8de72f3fba4d804a6e9697e7656589d4a8204476 (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
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 *   redistributing this file, you may do so under either license.
 *
 *   GPL LICENSE SUMMARY
 *
 *   Copyright(c) 2015 Intel Corporation. All rights reserved.
 *   Copyright(c) 2017 T-Platforms. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of version 2 of the GNU General Public License as
 *   published by the Free Software Foundation.
 *
 *   BSD LICENSE
 *
 *   Copyright(c) 2015 Intel Corporation. All rights reserved.
 *   Copyright(c) 2017 T-Platforms. All Rights Reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copy
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * PCIe NTB Perf Linux driver
 */

/*
 * How to use this tool, by example.
 *
 * Assuming $DBG_DIR is something like:
 * '/sys/kernel/debug/ntb_perf/0000:00:03.0'
 * Suppose aside from local device there is at least one remote device
 * connected to NTB with index 0.
 *-----------------------------------------------------------------------------
 * Eg: install driver with specified chunk/total orders and dma-enabled flag
 *
 * root@self# insmod ntb_perf.ko chunk_order=19 total_order=28 use_dma
 *-----------------------------------------------------------------------------
 * Eg: check NTB ports (index) and MW mapping information
 *
 * root@self# cat $DBG_DIR/info
 *-----------------------------------------------------------------------------
 * Eg: start performance test with peer (index 0) and get the test metrics
 *
 * root@self# echo 0 > $DBG_DIR/run
 * root@self# cat $DBG_DIR/run
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/pci.h>
#include <linux/ktime.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/sizes.h>
#include <linux/workqueue.h>
#include <linux/debugfs.h>
#include <linux/random.h>
#include <linux/ntb.h>

#define DRIVER_NAME		"ntb_perf"
#define DRIVER_VERSION		"2.0"

MODULE_LICENSE("Dual BSD/GPL");
MODULE_VERSION(DRIVER_VERSION);
MODULE_AUTHOR("Dave Jiang <dave.jiang@intel.com>");
MODULE_DESCRIPTION("PCIe NTB Performance Measurement Tool");

#define MAX_THREADS_CNT		32
#define DEF_THREADS_CNT		1
#define MAX_CHUNK_SIZE		SZ_1M
#define MAX_CHUNK_ORDER		20 /* no larger than 1M */

#define DMA_TRIES		100
#define DMA_MDELAY		10

#define MSG_TRIES		500
#define MSG_UDELAY_LOW		1000
#define MSG_UDELAY_HIGH		2000

#define PERF_BUF_LEN 1024

static unsigned long max_mw_size;
module_param(max_mw_size, ulong, 0644);
MODULE_PARM_DESC(max_mw_size, "Upper limit of memory window size");

static unsigned char chunk_order = 19; /* 512K */
module_param(chunk_order, byte, 0644);
MODULE_PARM_DESC(chunk_order, "Data chunk order [2^n] to transfer");

static unsigned char total_order = 30; /* 1G */
module_param(total_order, byte, 0644);
MODULE_PARM_DESC(total_order, "Total data order [2^n] to transfer");

static bool use_dma; /* default to 0 */
module_param(use_dma, bool, 0644);
MODULE_PARM_DESC(use_dma, "Use DMA engine to measure performance");

/*==============================================================================
 *                         Perf driver data definition
 *==============================================================================
 */

enum perf_cmd {
	PERF_CMD_INVAL = -1,/* invalid spad command */
	PERF_CMD_SSIZE = 0, /* send out buffer size */
	PERF_CMD_RSIZE = 1, /* recv in  buffer size */
	PERF_CMD_SXLAT = 2, /* send in  buffer xlat */
	PERF_CMD_RXLAT = 3, /* recv out buffer xlat */
	PERF_CMD_CLEAR = 4, /* clear allocated memory */
	PERF_STS_DONE  = 5, /* init is done */
	PERF_STS_LNKUP = 6, /* link up state flag */
};

struct perf_ctx;

struct perf_peer {
	struct perf_ctx	*perf;
	int pidx;
	int gidx;

	/* Outbound MW params */
	u64 outbuf_xlat;
	resource_size_t outbuf_size;
	void __iomem *outbuf;

	/* Inbound MW params */
	dma_addr_t inbuf_xlat;
	resource_size_t inbuf_size;
	void		*inbuf;

	/* NTB connection setup service */
	struct work_struct	service;
	unsigned long		sts;
};
#define to_peer_service(__work) \
	container_of(__work, struct perf_peer, service)

struct perf_thread {
	struct perf_ctx *perf;
	int tidx;

	/* DMA-based test sync parameters */
	atomic_t dma_sync;
	wait_queue_head_t dma_wait;
	struct dma_chan *dma_chan;

	/* Data source and measured statistics */
	void *src;
	u64 copied;
	ktime_t duration;
	int status;
	struct work_struct work;
};
#define to_thread_work(__work) \
	container_of(__work, struct perf_thread, work)

struct perf_ctx {
	struct ntb_dev *ntb;

	/* Global device index and peers descriptors */
	int gidx;
	int pcnt;
	struct perf_peer *peers;

	/* Performance measuring work-threads interface */
	unsigned long busy_flag;
	wait_queue_head_t twait;
	atomic_t tsync;
	u8 tcnt;
	struct perf_peer *test_peer;
	struct perf_thread threads[MAX_THREADS_CNT];

	/* Scratchpad/Message IO operations */
	int (*cmd_send)(struct perf_peer *peer, enum perf_cmd cmd, u64 data);
	int (*cmd_recv)(struct perf_ctx *perf, int *pidx, enum perf_cmd *cmd,
			u64 *data);

	struct dentry *dbgfs_dir;
};

/*
 * Scratchpads-base commands interface
 */
#define PERF_SPAD_CNT(_pcnt) \
	(3*((_pcnt) + 1))
#define PERF_SPAD_CMD(_gidx) \
	(3*(_gidx))
#define PERF_SPAD_LDATA(_gidx) \
	(3*(_gidx) + 1)
#define PERF_SPAD_HDATA(_gidx) \
	(3*(_gidx) + 2)
#define PERF_SPAD_NOTIFY(_gidx) \
	(BIT_ULL(_gidx))

/*
 * Messages-base commands interface
 */
#define PERF_MSG_CNT		3
#define PERF_MSG_CMD		0
#define PERF_MSG_LDATA		1
#define PERF_MSG_HDATA		2

/*==============================================================================
 *                           Static data declarations
 *==============================================================================
 */

static struct dentry *perf_dbgfs_topdir;

static struct workqueue_struct *perf_wq __read_mostly;

/*==============================================================================
 *                  NTB cross-link commands execution service
 *==============================================================================
 */

static void perf_terminate_test(struct perf_ctx *perf);

static inline bool perf_link_is_up(struct perf_peer *peer)
{
	u64 link;

	link = ntb_link_is_up(peer->perf->ntb, NULL, NULL);
	return !!(link & BIT_ULL_MASK(peer->pidx));
}

static int perf_spad_cmd_send(struct perf_peer *peer, enum perf_cmd cmd,
			      u64 data)
{
	struct perf_ctx *perf = peer->perf;
	int try;
	u32 sts;

	dev_dbg(&perf->ntb->dev, "CMD send: %d 0x%llx\n", cmd, data);

	/*
	 * Perform predefined number of attempts before give up.
	 * We are sending the data to the port specific scratchpad, so
	 * to prevent a multi-port access race-condition. Additionally
	 * there is no need in local locking since only thread-safe
	 * service work is using this method.
	 */
	for (try = 0; try < MSG_TRIES; try++) {
		if (!perf_link_is_up(peer))
			return -ENOLINK;

		sts = ntb_peer_spad_read(perf->ntb, peer->pidx,
					 PERF_SPAD_CMD(perf->gidx));
		if (le32_to_cpu(sts) != PERF_CMD_INVAL) {
			usleep_range(MSG_UDELAY_LOW, MSG_UDELAY_HIGH);
			continue;
		}

		ntb_peer_spad_write(perf->ntb, peer->pidx,
				    PERF_SPAD_LDATA(perf->gidx),
				    cpu_to_le32(lower_32_bits(data)));
		ntb_peer_spad_write(perf->ntb, peer->pidx,
				    PERF_SPAD_HDATA(perf->gidx),
				    cpu_to_le32(upper_32_bits(data)));
		mmiowb();
		ntb_peer_spad_write(perf->ntb, peer->pidx,
				    PERF_SPAD_CMD(perf->gidx),
				    cpu_to_le32(cmd));
		mmiowb();
		ntb_peer_db_set(perf->ntb, PERF_SPAD_NOTIFY(peer->gidx));

		dev_dbg(&perf->ntb->dev, "DB ring peer %#llx\n",
			PERF_SPAD_NOTIFY(peer->gidx));

		break;
	}

	return try < MSG_TRIES ? 0 : -EAGAIN;
}

static int perf_spad_cmd_recv(struct perf_ctx *perf, int *pidx,
			      enum perf_cmd *cmd, u64 *data)
{
	struct perf_peer *peer;
	u32 val;

	ntb_db_clear(perf->ntb, PERF_SPAD_NOTIFY(perf->gidx));

	/*
	 * We start scanning all over, since cleared DB may have been set
	 * by any peer. Yes, it makes peer with smaller index being
	 * serviced with greater priority, but it's convenient for spad
	 * and message code unification and simplicity.
	 */
	for (*pidx = 0; *pidx < perf->pcnt; (*pidx)++) {
		peer = &perf->peers[*pidx];

		if (!perf_link_is_up(peer))
			continue;

		val = ntb_spad_read(perf->ntb, PERF_SPAD_CMD(peer->gidx));
		val = le32_to_cpu(val);
		if (val == PERF_CMD_INVAL)
			continue;

		*cmd = val;

		val = ntb_spad_read(perf->ntb, PERF_SPAD_LDATA(peer->gidx));
		*data = le32_to_cpu(val);

		val = ntb_spad_read(perf->ntb, PERF_SPAD_HDATA(peer->gidx));
		*data |= (u64)le32_to_cpu(val) << 32;

		/* Next command can be retrieved from now */
		ntb_spad_write(perf->ntb, PERF_SPAD_CMD(peer->gidx),
			       cpu_to_le32(PERF_CMD_INVAL));

		dev_dbg(&perf->ntb->dev, "CMD recv: %d 0x%llx\n", *cmd, *data);

		return 0;
	}

	return -ENODATA;
}

static int perf_msg_cmd_send(struct perf_peer *peer, enum perf_cmd cmd,
			     u64 data)
{
	struct perf_ctx *perf = peer->perf;
	int try, ret;
	u64 outbits;

	dev_dbg(&perf->ntb->dev, "CMD send: %d 0x%llx\n", cmd, data);

	/*
	 * Perform predefined number of attempts before give up. Message
	 * registers are free of race-condition problem when accessed
	 * from different ports, so we don't need splitting registers
	 * by global device index. We also won't have local locking,
	 * since the method is used from service work only.
	 */
	outbits = ntb_msg_outbits(perf->ntb);
	for (try = 0; try < MSG_TRIES; try++) {
		if (!perf_link_is_up(peer))
			return -ENOLINK;

		ret = ntb_msg_clear_sts(perf->ntb, outbits);
		if (ret)
			return ret;

		ntb_peer_msg_write(perf->ntb, peer->pidx, PERF_MSG_LDATA,
			      cpu_to_le32(lower_32_bits(data)));

		if (ntb_msg_read_sts(perf->ntb) & outbits) {
			usleep_range(MSG_UDELAY_LOW, MSG_UDELAY_HIGH);
			continue;
		}

		ntb_peer_msg_write(perf->ntb, peer->pidx, PERF_MSG_HDATA,
			      cpu_to_le32(upper_32_bits(data)));
		mmiowb();

		/* This call shall trigger peer message event */
		ntb_peer_msg_write(perf->ntb, peer->pidx, PERF_MSG_CMD,
			      cpu_to_le32(cmd));

		break;
	}

	return try < MSG_TRIES ? 0 : -EAGAIN;
}

static int perf_msg_cmd_recv(struct perf_ctx *perf, int *pidx,
			     enum perf_cmd *cmd, u64 *data)
{
	u64 inbits;
	u32 val;

	inbits = ntb_msg_inbits(perf->ntb);

	if (hweight64(ntb_msg_read_sts(perf->ntb) & inbits) < 3)
		return -ENODATA;

	val = ntb_msg_read(perf->ntb, pidx, PERF_MSG_CMD);
	*cmd = le32_to_cpu(val);

	val = ntb_msg_read(perf->ntb, pidx, PERF_MSG_LDATA);
	*data = le32_to_cpu(val);

	val = ntb_msg_read(perf->ntb, pidx, PERF_MSG_HDATA);
	*data |= (u64)le32_to_cpu(val) << 32;

	/* Next command can be retrieved from now */
	ntb_msg_clear_sts(perf->ntb, inbits);

	dev_dbg(&perf->ntb->dev, "CMD recv: %d 0x%llx\n", *cmd, *data);

	return 0;
}

static int perf_cmd_send(struct perf_peer *peer, enum perf_cmd cmd, u64 data)
{
	struct perf_ctx *perf = peer->perf;

	if (cmd == PERF_CMD_SSIZE || cmd == PERF_CMD_SXLAT)
		return perf->cmd_send(peer, cmd, data);

	dev_err(&perf->ntb->dev, "Send invalid command\n");
	return -EINVAL;
}

static int perf_cmd_exec(struct perf_peer *peer, enum perf_cmd cmd)
{
	switch (cmd) {
	case PERF_CMD_SSIZE:
	case PERF_CMD_RSIZE:
	case PERF_CMD_SXLAT:
	case PERF_CMD_RXLAT:
	case PERF_CMD_CLEAR:
		break;
	default:
		dev_err(&peer->perf->ntb->dev, "Exec invalid command\n");
		return -EINVAL;
	}

	/* No need of memory barrier, since bit ops have invernal lock */
	set_bit(cmd, &peer->sts);

	dev_dbg(&peer->perf->ntb->dev, "CMD exec: %d\n", cmd);

	(void)queue_work(system_highpri_wq, &peer->service);

	return 0;
}

static int perf_cmd_recv(struct perf_ctx *perf)
{
	struct perf_peer *peer;
	int ret, pidx, cmd;
	u64 data;

	while (!(ret = perf->cmd_recv(perf, &pidx, &cmd, &data))) {
		peer = &perf->peers[pidx];

		switch (cmd) {
		case PERF_CMD_SSIZE:
			peer->inbuf_size = data;
			return perf_cmd_exec(peer, PERF_CMD_RSIZE);
		case PERF_CMD_SXLAT:
			peer->outbuf_xlat = data;
			return perf_cmd_exec(peer, PERF_CMD_RXLAT);
		default:
			dev_err(&perf->ntb->dev, "Recv invalid command\n");
			return -EINVAL;
		}
	}

	/* Return 0 if no data left to process, otherwise an error */
	return ret == -ENODATA ? 0 : ret;
}

static void perf_link_event(void *ctx)
{
	struct perf_ctx *perf = ctx;
	struct perf_peer *peer;
	bool lnk_up;
	int pidx;

	for (pidx = 0; pidx < perf->pcnt; pidx++) {
		peer = &perf->peers[pidx];

		lnk_up = perf_link_is_up(peer);

		if (lnk_up &&
		    !test_and_set_bit(PERF_STS_LNKUP, &peer->sts)) {
			perf_cmd_exec(peer, PERF_CMD_SSIZE);
		} else if (!lnk_up &&
			   test_and_clear_bit(PERF_STS_LNKUP, &peer->sts)) {
			perf_cmd_exec(peer, PERF_CMD_CLEAR);
		}
	}
}

static void perf_db_event(void *ctx, int vec)
{
	struct perf_ctx *perf = ctx;

	dev_dbg(&perf->ntb->dev, "DB vec %d mask %#llx bits %#llx\n", vec,
		ntb_db_vector_mask(perf->ntb, vec), ntb_db_read(perf->ntb));

	/* Just receive all available commands */
	(void)perf_cmd_recv(perf);
}

static void perf_msg_event(void *ctx)
{
	struct perf_ctx *perf = ctx;

	dev_dbg(&perf->ntb->dev, "Msg status bits %#llx\n",
		ntb_msg_read_sts(perf->ntb));

	/* Messages are only sent one-by-one */
	(void)perf_cmd_recv(perf);
}

static const struct ntb_ctx_ops perf_ops = {
	.link_event = perf_link_event,
	.db_event = perf_db_event,
	.msg_event = perf_msg_event
};

static void perf_free_outbuf(struct perf_peer *peer)
{
	(void)ntb_peer_mw_clear_trans(peer->perf->ntb, peer->pidx, peer->gidx);
}

static int perf_setup_outbuf(struct perf_peer *peer)
{
	struct perf_ctx *perf = peer->perf;
	int ret;

	/* Outbuf size can be unaligned due to custom max_mw_size */
	ret = ntb_peer_mw_set_trans(perf->ntb, peer->pidx, peer->gidx,
				    peer->outbuf_xlat, peer->outbuf_size);
	if (ret) {
		dev_err(&perf->ntb->dev, "Failed to set outbuf translation\n");
		return ret;
	}

	/* Initialization is finally done */
	set_bit(PERF_STS_DONE, &peer->sts);

	return 0;
}

static void perf_free_inbuf(struct perf_peer *peer)
{
	if (!peer->inbuf)
		return;

	(void)ntb_mw_clear_trans(peer->perf->ntb, peer->pidx, peer->gidx);
	dma_free_coherent(&peer->perf->ntb->dev, peer->inbuf_size,
			  peer->inbuf, peer->inbuf_xlat);
	peer->inbuf = NULL;
}

static int perf_setup_inbuf(struct perf_peer *peer)
{
	resource_size_t xlat_align, size_align, size_max;
	struct perf_ctx *perf = peer->perf;
	int ret;

	/* Get inbound MW parameters */
	ret = ntb_mw_get_align(perf->ntb, peer->pidx, perf->gidx,
			       &xlat_align, &size_align, &size_max);
	if (ret) {
		dev_err(&perf->ntb->dev, "Couldn't get inbuf restrictions\n");
		return ret;
	}

	if (peer->inbuf_size > size_max) {
		dev_err(&perf->ntb->dev, "Too big inbuf size %pa > %pa\n",
			&peer->inbuf_size, &size_max);
		return -EINVAL;
	}

	peer->inbuf_size = round_up(peer->inbuf_size, size_align);

	perf_free_inbuf(peer);

	peer->inbuf = dma_alloc_coherent(&perf->ntb->dev, peer->inbuf_size,
					 &peer->inbuf_xlat, GFP_KERNEL);
	if (!peer->inbuf) {
		dev_err(&perf->ntb->dev, "Failed to alloc inbuf of %pa\n",
			&peer->inbuf_size);
		return -ENOMEM;
	}
	if (!IS_ALIGNED(peer->inbuf_xlat, xlat_align)) {
		dev_err(&perf->ntb->dev, "Unaligned inbuf allocated\n");
		goto err_free_inbuf;
	}

	ret = ntb_mw_set_trans(perf->ntb, peer->pidx, peer->gidx,
			       peer->inbuf_xlat, peer->inbuf_size);
	if (ret) {
		dev_err(&perf->ntb->dev, "Failed to set inbuf translation\n");
		goto err_free_inbuf;
	}

	/*
	 * We submit inbuf xlat transmission cmd for execution here to follow
	 * the code architecture, even though this method is called from service
	 * work itself so the command will be executed right after it returns.
	 */
	(void)perf_cmd_exec(peer, PERF_CMD_SXLAT);

	return 0;

err_free_inbuf:
	perf_free_inbuf(peer);

	return ret;
}

static void perf_service_work(struct work_struct *work)
{
	struct perf_peer *peer = to_peer_service(work);

	if (test_and_clear_bit(PERF_CMD_SSIZE, &peer->sts))
		perf_cmd_send(peer, PERF_CMD_SSIZE, peer->outbuf_size);

	if (test_and_clear_bit(PERF_CMD_RSIZE, &peer->sts))
		perf_setup_inbuf(peer);

	if (test_and_clear_bit(PERF_CMD_SXLAT, &peer->sts))
		perf_cmd_send(peer, PERF_CMD_SXLAT, peer->inbuf_xlat);

	if (test_and_clear_bit(PERF_CMD_RXLAT, &peer->sts))
		perf_setup_outbuf(peer);

	if (test_and_clear_bit(PERF_CMD_CLEAR, &peer->sts)) {
		clear_bit(PERF_STS_DONE, &peer->sts);
		if (test_bit(0, &peer->perf->busy_flag) &&
		    peer == peer->perf->test_peer) {
			dev_warn(&peer->perf->ntb->dev,
				"Freeing while test on-fly\n");
			perf_terminate_test(peer->perf);
		}
		perf_free_outbuf(peer);
		perf_free_inbuf(peer);
	}
}

static int perf_init_service(struct perf_ctx *perf)
{
	u64 mask;

	if (ntb_peer_mw_count(perf->ntb) < perf->pcnt + 1) {
		dev_err(&perf->ntb->dev, "Not enough memory windows\n");
		return -EINVAL;
	}

	if (ntb_msg_count(perf->ntb) >= PERF_MSG_CNT) {
		perf->cmd_send = perf_msg_cmd_send;
		perf->cmd_recv = perf_msg_cmd_recv;

		dev_dbg(&perf->ntb->dev, "Message service initialized\n");

		return 0;
	}

	dev_dbg(&perf->ntb->dev, "Message service unsupported\n");

	mask = GENMASK_ULL(perf->pcnt, 0);
	if (ntb_spad_count(perf->ntb) >= PERF_SPAD_CNT(perf->pcnt) &&
	    (ntb_db_valid_mask(perf->ntb) & mask) == mask) {
		perf->cmd_send = perf_spad_cmd_send;
		perf->cmd_recv = perf_spad_cmd_recv;

		dev_dbg(&perf->ntb->dev, "Scratchpad service initialized\n");

		return 0;
	}

	dev_dbg(&perf->ntb->dev, "Scratchpad service unsupported\n");

	dev_err(&perf->ntb->dev, "Command services unsupported\n");

	return -EINVAL;
}

static int perf_enable_service(struct perf_ctx *perf)
{
	u64 mask, incmd_bit;
	int ret, sidx, scnt;

	mask = ntb_db_valid_mask(perf->ntb);
	(void)ntb_db_set_mask(perf->ntb, mask);

	ret = ntb_set_ctx(perf->ntb, perf, &perf_ops);
	if (ret)
		return ret;

	if (perf->cmd_send == perf_msg_cmd_send) {
		u64 inbits, outbits;

		inbits = ntb_msg_inbits(perf->ntb);
		outbits = ntb_msg_outbits(perf->ntb);
		(void)ntb_msg_set_mask(perf->ntb, inbits | outbits);

		incmd_bit = BIT_ULL(__ffs64(inbits));
		ret = ntb_msg_clear_mask(perf->ntb, incmd_bit);

		dev_dbg(&perf->ntb->dev, "MSG sts unmasked %#llx\n", incmd_bit);
	} else {
		scnt = ntb_spad_count(perf->ntb);
		for (sidx = 0; sidx < scnt; sidx++)
			ntb_spad_write(perf->ntb, sidx, PERF_CMD_INVAL);
		incmd_bit = PERF_SPAD_NOTIFY(perf->gidx);
		ret = ntb_db_clear_mask(perf->ntb, incmd_bit);

		dev_dbg(&perf->ntb->dev, "DB bits unmasked %#llx\n", incmd_bit);
	}
	if (ret) {
		ntb_clear_ctx(perf->ntb);
		return ret;
	}

	ntb_link_enable(perf->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
	/* Might be not necessary */
	ntb_link_event(perf->ntb);

	return 0;
}

static void perf_disable_service(struct perf_ctx *perf)
{
	int pidx;

	ntb_link_disable(perf->ntb);

	if (perf->cmd_send == perf_msg_cmd_send) {
		u64 inbits;

		inbits = ntb_msg_inbits(perf->ntb);
		(void)ntb_msg_set_mask(perf->ntb, inbits);
	} else {
		(void)ntb_db_set_mask(perf->ntb, PERF_SPAD_NOTIFY(perf->gidx));
	}

	ntb_clear_ctx(perf->ntb);

	for (pidx = 0; pidx < perf->pcnt; pidx++)
		perf_cmd_exec(&perf->peers[pidx], PERF_CMD_CLEAR);

	for (pidx = 0; pidx < perf->pcnt; pidx++)
		flush_work(&perf->peers[pidx].service);
}

/*==============================================================================
 *                      Performance measuring work-thread
 *==============================================================================
 */

static void perf_dma_copy_callback(void *data)
{
	struct perf_thread *pthr = data;

	atomic_dec(&pthr->dma_sync);
	wake_up(&pthr->dma_wait);
}

static int perf_copy_chunk(struct perf_thread *pthr,
			   void __iomem *dst, void *src, size_t len)
{
	struct dma_async_tx_descriptor *tx;
	struct dmaengine_unmap_data *unmap;
	struct device *dma_dev;
	int try = 0, ret = 0;

	if (!use_dma) {
		memcpy_toio(dst, src, len);
		goto ret_check_tsync;
	}

	dma_dev = pthr->dma_chan->device->dev;

	if (!is_dma_copy_aligned(pthr->dma_chan->device, offset_in_page(src),
				 offset_in_page(dst), len))
		return -EIO;

	unmap = dmaengine_get_unmap_data(dma_dev, 2, GFP_NOWAIT);
	if (!unmap)
		return -ENOMEM;

	unmap->len = len;
	unmap->addr[0] = dma_map_page(dma_dev, virt_to_page(src),
		offset_in_page(src), len, DMA_TO_DEVICE);
	if (dma_mapping_error(dma_dev, unmap->addr[0])) {
		ret = -EIO;
		goto err_free_resource;
	}
	unmap->to_cnt = 1;

	unmap->addr[1] = dma_map_page(dma_dev, virt_to_page(dst),
		offset_in_page(dst), len, DMA_FROM_DEVICE);
	if (dma_mapping_error(dma_dev, unmap->addr[1])) {
		ret = -EIO;
		goto err_free_resource;
	}
	unmap->from_cnt = 1;

	do {
		tx = dmaengine_prep_dma_memcpy(pthr->dma_chan, unmap->addr[1],
			unmap->addr[0], len, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
		if (!tx)
			msleep(DMA_MDELAY);
	} while (!tx && (try++ < DMA_TRIES));

	if (!tx) {
		ret = -EIO;
		goto err_free_resource;
	}

	tx->callback = perf_dma_copy_callback;
	tx->callback_param = pthr;
	dma_set_unmap(tx, unmap);

	if (dma_submit_error(dmaengine_submit(tx))) {
		dmaengine_unmap_put(unmap);
		goto err_free_resource;
	}

	dmaengine_unmap_put(unmap);

	atomic_inc(&pthr->dma_sync);
	dma_async_issue_pending(pthr->dma_chan);

ret_check_tsync:
	return likely(atomic_read(&pthr->perf->tsync) > 0) ? 0 : -EINTR;

err_free_resource:
	dmaengine_unmap_put(unmap);

	return ret;
}

static bool perf_dma_filter(struct dma_chan *chan, void *data)
{
	struct perf_ctx *perf = data;
	int node;

	node = dev_to_node(&perf->ntb->dev);

	return node == NUMA_NO_NODE || node == dev_to_node(chan->device->dev);
}

static int perf_init_test(struct perf_thread *pthr)
{
	struct perf_ctx *perf = pthr->perf;
	dma_cap_mask_t dma_mask;

	pthr->src = kmalloc_node(perf->test_peer->outbuf_size, GFP_KERNEL,
				 dev_to_node(&perf->ntb->dev));
	if (!pthr->src)
		return -ENOMEM;

	get_random_bytes(pthr->src, perf->test_peer->outbuf_size);

	if (!use_dma)
		return 0;

	dma_cap_zero(dma_mask);
	dma_cap_set(DMA_MEMCPY, dma_mask);
	pthr->dma_chan = dma_request_channel(dma_mask, perf_dma_filter, perf);
	if (!pthr->dma_chan) {
		dev_err(&perf->ntb->dev, "%d: Failed to get DMA channel\n",
			pthr->tidx);
		atomic_dec(&perf->tsync);
		wake_up(&perf->twait);
		kfree(pthr->src);
		return -ENODEV;
	}

	atomic_set(&pthr->dma_sync, 0);

	return 0;
}

static int perf_run_test(struct perf_thread *pthr)
{
	struct perf_peer *peer = pthr->perf->test_peer;
	struct perf_ctx *perf = pthr->perf;
	void __iomem *flt_dst, *bnd_dst;
	u64 total_size, chunk_size;
	void *flt_src;
	int ret = 0;

	total_size = 1ULL << total_order;
	chunk_size = 1ULL << chunk_order;
	chunk_size = min_t(u64, peer->outbuf_size, chunk_size);

	flt_src = pthr->src;
	bnd_dst = peer->outbuf + peer->outbuf_size;
	flt_dst = peer->outbuf;

	pthr->duration = ktime_get();

	/* Copied field is cleared on test launch stage */
	while (pthr->copied < total_size) {
		ret = perf_copy_chunk(pthr, flt_dst, flt_src, chunk_size);
		if (ret) {
			dev_err(&perf->ntb->dev, "%d: Got error %d on test\n",
				pthr->tidx, ret);
			return ret;
		}

		pthr->copied += chunk_size;

		flt_dst += chunk_size;
		flt_src += chunk_size;
		if (flt_dst >= bnd_dst || flt_dst < peer->outbuf) {
			flt_dst = peer->outbuf;
			flt_src = pthr->src;
		}

		/* Give up CPU to give a chance for other threads to use it */
		schedule();
	}

	return 0;
}

static int perf_sync_test(struct perf_thread *pthr)
{
	struct perf_ctx *perf = pthr->perf;

	if (!use_dma)
		goto no_dma_ret;

	wait_event(pthr->dma_wait,
		   (atomic_read(&pthr->dma_sync) == 0 ||
		    atomic_read(&perf->tsync) < 0));

	if (atomic_read(&perf->tsync) < 0)
		return -EINTR;

no_dma_ret:
	pthr->duration = ktime_sub(ktime_get(), pthr->duration);

	dev_dbg(&perf->ntb->dev, "%d: copied %llu bytes\n",
		pthr->tidx, pthr->copied);

	dev_dbg(&perf->ntb->dev, "%d: lasted %llu usecs\n",
		pthr->tidx, ktime_to_us(pthr->duration));

	dev_dbg(&perf->ntb->dev, "%d: %llu MBytes/s\n", pthr->tidx,
		div64_u64(pthr->copied, ktime_to_us(pthr->duration)));

	return 0;
}

static void perf_clear_test(struct perf_thread *pthr)
{
	struct perf_ctx *perf = pthr->perf;

	if (!use_dma)
		goto no_dma_notify;

	/*
	 * If test finished without errors, termination isn't needed.
	 * We call it anyway just to be sure of the transfers completion.
	 */
	(void)dmaengine_terminate_sync(pthr->dma_chan);

	dma_release_channel(pthr->dma_chan);

no_dma_notify:
	atomic_dec(&perf->tsync);
	wake_up(&perf->twait);
	kfree(pthr->src);
}

static void perf_thread_work(struct work_struct *work)
{
	struct perf_thread *pthr = to_thread_work(work);
	int ret;

	/*
	 * Perform stages in compliance with use_dma flag value.
	 * Test status is changed only if error happened, otherwise
	 * status -ENODATA is kept while test is on-fly. Results
	 * synchronization is performed only if test fininshed
	 * without an error or interruption.
	 */
	ret = perf_init_test(pthr);
	if (ret) {
		pthr->status = ret;
		return;
	}

	ret = perf_run_test(pthr);
	if (ret) {
		pthr->status = ret;
		goto err_clear_test;
	}

	pthr->status = perf_sync_test(pthr);

err_clear_test:
	perf_clear_test(pthr);
}

static int perf_set_tcnt(struct perf_ctx *perf, u8 tcnt)
{
	if (tcnt == 0 || tcnt > MAX_THREADS_CNT)
		return -EINVAL;

	if (test_and_set_bit_lock(0, &perf->busy_flag))
		return -EBUSY;

	perf->tcnt = tcnt;

	clear_bit_unlock(0, &perf->busy_flag);

	return 0;
}

static void perf_terminate_test(struct perf_ctx *perf)
{
	int tidx;

	atomic_set(&perf->tsync, -1);
	wake_up(&perf->twait);

	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
		wake_up(&perf->threads[tidx].dma_wait);
		cancel_work_sync(&perf->threads[tidx].work);
	}
}

static int perf_submit_test(struct perf_peer *peer)
{
	struct perf_ctx *perf = peer->perf;
	struct perf_thread *pthr;
	int tidx, ret;

	if (!test_bit(PERF_STS_DONE, &peer->sts))
		return -ENOLINK;

	if (test_and_set_bit_lock(0, &perf->busy_flag))
		return -EBUSY;

	perf->test_peer = peer;
	atomic_set(&perf->tsync, perf->tcnt);

	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
		pthr = &perf->threads[tidx];

		pthr->status = -ENODATA;
		pthr->copied = 0;
		pthr->duration = ktime_set(0, 0);
		if (tidx < perf->tcnt)
			(void)queue_work(perf_wq, &pthr->work);
	}

	ret = wait_event_interruptible(perf->twait,
				       atomic_read(&perf->tsync) <= 0);
	if (ret == -ERESTARTSYS) {
		perf_terminate_test(perf);
		ret = -EINTR;
	}

	clear_bit_unlock(0, &perf->busy_flag);

	return ret;
}

static int perf_read_stats(struct perf_ctx *perf, char *buf,
			   size_t size, ssize_t *pos)
{
	struct perf_thread *pthr;
	int tidx;

	if (test_and_set_bit_lock(0, &perf->busy_flag))
		return -EBUSY;

	(*pos) += scnprintf(buf + *pos, size - *pos,
		"    Peer %d test statistics:\n", perf->test_peer->pidx);

	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
		pthr = &perf->threads[tidx];

		if (pthr->status == -ENODATA)
			continue;

		if (pthr->status) {
			(*pos) += scnprintf(buf + *pos, size - *pos,
				"%d: error status %d\n", tidx, pthr->status);
			continue;
		}

		(*pos) += scnprintf(buf + *pos, size - *pos,
			"%d: copied %llu bytes in %llu usecs, %llu MBytes/s\n",
			tidx, pthr->copied, ktime_to_us(pthr->duration),
			div64_u64(pthr->copied, ktime_to_us(pthr->duration)));
	}

	clear_bit_unlock(0, &perf->busy_flag);

	return 0;
}

static void perf_init_threads(struct perf_ctx *perf)
{
	struct perf_thread *pthr;
	int tidx;

	perf->tcnt = DEF_THREADS_CNT;
	perf->test_peer = &perf->peers[0];
	init_waitqueue_head(&perf->twait);

	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
		pthr = &perf->threads[tidx];

		pthr->perf = perf;
		pthr->tidx = tidx;
		pthr->status = -ENODATA;
		init_waitqueue_head(&pthr->dma_wait);
		INIT_WORK(&pthr->work, perf_thread_work);
	}
}

static void perf_clear_threads(struct perf_ctx *perf)
{
	perf_terminate_test(perf);
}

/*==============================================================================
 *                               DebugFS nodes
 *==============================================================================
 */

static ssize_t perf_dbgfs_read_info(struct file *filep, char __user *ubuf,
				    size_t size, loff_t *offp)
{
	struct perf_ctx *perf = filep->private_data;
	struct perf_peer *peer;
	size_t buf_size;
	ssize_t pos = 0;
	int ret, pidx;
	char *buf;

	buf_size = min_t(size_t, size, 0x1000U);

	buf = kmalloc(buf_size, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	pos += scnprintf(buf + pos, buf_size - pos,
		"    Performance measuring tool info:\n\n");

	pos += scnprintf(buf + pos, buf_size - pos,
		"Local port %d, Global index %d\n", ntb_port_number(perf->ntb),
		perf->gidx);
	pos += scnprintf(buf + pos, buf_size - pos, "Test status: ");
	if (test_bit(0, &perf->busy_flag)) {
		pos += scnprintf(buf + pos, buf_size - pos,
			"on-fly with port %d (%d)\n",
			ntb_peer_port_number(perf->ntb, perf->test_peer->pidx),
			perf->test_peer->pidx);
	} else {
		pos += scnprintf(buf + pos, buf_size - pos, "idle\n");
	}

	for (pidx = 0; pidx < perf->pcnt; pidx++) {
		peer = &perf->peers[pidx];

		pos += scnprintf(buf + pos, buf_size - pos,
			"Port %d (%d), Global index %d:\n",
			ntb_peer_port_number(perf->ntb, peer->pidx), peer->pidx,
			peer->gidx);

		pos += scnprintf(buf + pos, buf_size - pos,
			"\tLink status: %s\n",
			test_bit(PERF_STS_LNKUP, &peer->sts) ? "up" : "down");

		pos += scnprintf(buf + pos, buf_size - pos,
			"\tOut buffer addr 0x%pK\n", peer->outbuf);

		pos += scnprintf(buf + pos, buf_size - pos,
			"\tOut buffer size %pa\n", &peer->outbuf_size);

		pos += scnprintf(buf + pos, buf_size - pos,
			"\tOut buffer xlat 0x%016llx[p]\n", peer->outbuf_xlat);

		if (!peer->inbuf) {
			pos += scnprintf(buf + pos, buf_size - pos,
				"\tIn buffer addr: unallocated\n");
			continue;
		}

		pos += scnprintf(buf + pos, buf_size - pos,
			"\tIn buffer addr 0x%pK\n", peer->inbuf);

		pos += scnprintf(buf + pos, buf_size - pos,
			"\tIn buffer size %pa\n", &peer->inbuf_size);

		pos += scnprintf(buf + pos, buf_size - pos,
			"\tIn buffer xlat %pad[p]\n", &peer->inbuf_xlat);
	}

	ret = simple_read_from_buffer(ubuf, size, offp, buf, pos);
	kfree(buf);

	return ret;
}

static const struct file_operations perf_dbgfs_info = {
	.open = simple_open,
	.read = perf_dbgfs_read_info
};

static ssize_t perf_dbgfs_read_run(struct file *filep, char __user *ubuf,
				   size_t size, loff_t *offp)
{
	struct perf_ctx *perf = filep->private_data;
	ssize_t ret, pos = 0;
	char *buf;

	buf = kmalloc(PERF_BUF_LEN, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	ret = perf_read_stats(perf, buf, PERF_BUF_LEN, &pos);
	if (ret)
		goto err_free;

	ret = simple_read_from_buffer(ubuf, size, offp, buf, pos);
err_free:
	kfree(buf);

	return ret;
}

static ssize_t perf_dbgfs_write_run(struct file *filep, const char __user *ubuf,
				    size_t size, loff_t *offp)
{
	struct perf_ctx *perf = filep->private_data;
	struct perf_peer *peer;
	int pidx, ret;

	ret = kstrtoint_from_user(ubuf, size, 0, &pidx);
	if (ret)
		return ret;

	if (pidx < 0 || pidx >= perf->pcnt)
		return -EINVAL;

	peer = &perf->peers[pidx];

	ret = perf_submit_test(peer);
	if (ret)
		return ret;

	return size;
}

static const struct file_operations perf_dbgfs_run = {
	.open = simple_open,
	.read = perf_dbgfs_read_run,
	.write = perf_dbgfs_write_run
};

static ssize_t perf_dbgfs_read_tcnt(struct file *filep, char __user *ubuf,
				    size_t size, loff_t *offp)
{
	struct perf_ctx *perf = filep->private_data;
	char buf[8];
	ssize_t pos;

	pos = scnprintf(buf, sizeof(buf), "%hhu\n", perf->tcnt);

	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
}

static ssize_t perf_dbgfs_write_tcnt(struct file *filep,
				     const char __user *ubuf,
				     size_t size, loff_t *offp)
{
	struct perf_ctx *perf = filep->private_data;
	int ret;
	u8 val;

	ret = kstrtou8_from_user(ubuf, size, 0, &val);
	if (ret)
		return ret;

	ret = perf_set_tcnt(perf, val);
	if (ret)
		return ret;

	return size;
}

static const struct file_operations perf_dbgfs_tcnt = {
	.open = simple_open,
	.read = perf_dbgfs_read_tcnt,
	.write = perf_dbgfs_write_tcnt
};

static void perf_setup_dbgfs(struct perf_ctx *perf)
{
	struct pci_dev *pdev = perf->ntb->pdev;

	perf->dbgfs_dir = debugfs_create_dir(pci_name(pdev), perf_dbgfs_topdir);
	if (!perf->dbgfs_dir) {
		dev_warn(&perf->ntb->dev, "DebugFS unsupported\n");
		return;
	}

	debugfs_create_file("info", 0600, perf->dbgfs_dir, perf,
			    &perf_dbgfs_info);

	debugfs_create_file("run", 0600, perf->dbgfs_dir, perf,
			    &perf_dbgfs_run);

	debugfs_create_file("threads_count", 0600, perf->dbgfs_dir, perf,
			    &perf_dbgfs_tcnt);

	/* They are made read-only for test exec safety and integrity */
	debugfs_create_u8("chunk_order", 0500, perf->dbgfs_dir, &chunk_order);

	debugfs_create_u8("total_order", 0500, perf->dbgfs_dir, &total_order);

	debugfs_create_bool("use_dma", 0500, perf->dbgfs_dir, &use_dma);
}

static void perf_clear_dbgfs(struct perf_ctx *perf)
{
	debugfs_remove_recursive(perf->dbgfs_dir);
}

/*==============================================================================
 *                        Basic driver initialization
 *==============================================================================
 */

static struct perf_ctx *perf_create_data(struct ntb_dev *ntb)
{
	struct perf_ctx *perf;

	perf = devm_kzalloc(&ntb->dev, sizeof(*perf), GFP_KERNEL);
	if (!perf)
		return ERR_PTR(-ENOMEM);

	perf->pcnt = ntb_peer_port_count(ntb);
	perf->peers = devm_kcalloc(&ntb->dev, perf->pcnt, sizeof(*perf->peers),
				  GFP_KERNEL);
	if (!perf->peers)
		return ERR_PTR(-ENOMEM);

	perf->ntb = ntb;

	return perf;
}

static int perf_setup_peer_mw(struct perf_peer *peer)
{
	struct perf_ctx *perf = peer->perf;
	phys_addr_t phys_addr;
	int ret;

	/* Get outbound MW parameters and map it */
	ret = ntb_peer_mw_get_addr(perf->ntb, peer->gidx, &phys_addr,
				   &peer->outbuf_size);
	if (ret)
		return ret;

	peer->outbuf = devm_ioremap_wc(&perf->ntb->dev, phys_addr,
					peer->outbuf_size);
	if (!peer->outbuf)
		return -ENOMEM;

	if (max_mw_size && peer->outbuf_size > max_mw_size) {
		peer->outbuf_size = max_mw_size;
		dev_warn(&peer->perf->ntb->dev,
			"Peer %d outbuf reduced to %#llx\n", peer->pidx,
			peer->outbuf_size);
	}

	return 0;
}

static int perf_init_peers(struct perf_ctx *perf)
{
	struct perf_peer *peer;
	int pidx, lport, ret;

	lport = ntb_port_number(perf->ntb);
	perf->gidx = -1;
	for (pidx = 0; pidx < perf->pcnt; pidx++) {
		peer = &perf->peers[pidx];

		peer->perf = perf;
		peer->pidx = pidx;
		if (lport < ntb_peer_port_number(perf->ntb, pidx)) {
			if (perf->gidx == -1)
				perf->gidx = pidx;
			peer->gidx = pidx + 1;
		} else {
			peer->gidx = pidx;
		}
		INIT_WORK(&peer->service, perf_service_work);
	}
	if (perf->gidx == -1)
		perf->gidx = pidx;

	for (pidx = 0; pidx < perf->pcnt; pidx++) {
		ret = perf_setup_peer_mw(&perf->peers[pidx]);
		if (ret)
			return ret;
	}

	dev_dbg(&perf->ntb->dev, "Global port index %d\n", perf->gidx);

	return 0;
}

static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb)
{
	struct perf_ctx *perf;
	int ret;

	perf = perf_create_data(ntb);
	if (IS_ERR(perf))
		return PTR_ERR(perf);

	ret = perf_init_peers(perf);
	if (ret)
		return ret;

	perf_init_threads(perf);

	ret = perf_init_service(perf);
	if (ret)
		return ret;

	ret = perf_enable_service(perf);
	if (ret)
		return ret;

	perf_setup_dbgfs(perf);

	return 0;
}

static void perf_remove(struct ntb_client *client, struct ntb_dev *ntb)
{
	struct perf_ctx *perf = ntb->ctx;

	perf_clear_dbgfs(perf);

	perf_disable_service(perf);

	perf_clear_threads(perf);
}

static struct ntb_client perf_client = {
	.ops = {
		.probe = perf_probe,
		.remove = perf_remove
	}
};

static int __init perf_init(void)
{
	int ret;

	if (chunk_order > MAX_CHUNK_ORDER) {
		chunk_order = MAX_CHUNK_ORDER;
		pr_info("Chunk order reduced to %hhu\n", chunk_order);
	}

	if (total_order < chunk_order) {
		total_order = chunk_order;
		pr_info("Total data order reduced to %hhu\n", total_order);
	}

	perf_wq = alloc_workqueue("perf_wq", WQ_UNBOUND | WQ_SYSFS, 0);
	if (!perf_wq)
		return -ENOMEM;

	if (debugfs_initialized())
		perf_dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);

	ret = ntb_register_client(&perf_client);
	if (ret) {
		debugfs_remove_recursive(perf_dbgfs_topdir);
		destroy_workqueue(perf_wq);
	}

	return ret;
}
module_init(perf_init);

static void __exit perf_exit(void)
{
	ntb_unregister_client(&perf_client);
	debugfs_remove_recursive(perf_dbgfs_topdir);
	destroy_workqueue(perf_wq);
}
module_exit(perf_exit);