aboutsummaryrefslogtreecommitdiff
path: root/drivers/misc/mic/scif/scif_rma.c
blob: c824329f7012adfc765e4b1872185f5b148fd445 (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
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
/*
 * Intel MIC Platform Software Stack (MPSS)
 *
 * Copyright(c) 2015 Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * Intel SCIF driver.
 *
 */
#include <linux/dma_remapping.h>
#include <linux/pagemap.h>
#include <linux/sched/mm.h>
#include <linux/sched/signal.h>

#include "scif_main.h"
#include "scif_map.h"

/* Used to skip ulimit checks for registrations with SCIF_MAP_KERNEL flag */
#define SCIF_MAP_ULIMIT 0x40

bool scif_ulimit_check = 1;

/**
 * scif_rma_ep_init:
 * @ep: end point
 *
 * Initialize RMA per EP data structures.
 */
void scif_rma_ep_init(struct scif_endpt *ep)
{
	struct scif_endpt_rma_info *rma = &ep->rma_info;

	mutex_init(&rma->rma_lock);
	init_iova_domain(&rma->iovad, PAGE_SIZE, SCIF_IOVA_START_PFN);
	spin_lock_init(&rma->tc_lock);
	mutex_init(&rma->mmn_lock);
	INIT_LIST_HEAD(&rma->reg_list);
	INIT_LIST_HEAD(&rma->remote_reg_list);
	atomic_set(&rma->tw_refcount, 0);
	atomic_set(&rma->tcw_refcount, 0);
	atomic_set(&rma->tcw_total_pages, 0);
	atomic_set(&rma->fence_refcount, 0);

	rma->async_list_del = 0;
	rma->dma_chan = NULL;
	INIT_LIST_HEAD(&rma->mmn_list);
	INIT_LIST_HEAD(&rma->vma_list);
	init_waitqueue_head(&rma->markwq);
}

/**
 * scif_rma_ep_can_uninit:
 * @ep: end point
 *
 * Returns 1 if an endpoint can be uninitialized and 0 otherwise.
 */
int scif_rma_ep_can_uninit(struct scif_endpt *ep)
{
	int ret = 0;

	mutex_lock(&ep->rma_info.rma_lock);
	/* Destroy RMA Info only if both lists are empty */
	if (list_empty(&ep->rma_info.reg_list) &&
	    list_empty(&ep->rma_info.remote_reg_list) &&
	    list_empty(&ep->rma_info.mmn_list) &&
	    !atomic_read(&ep->rma_info.tw_refcount) &&
	    !atomic_read(&ep->rma_info.tcw_refcount) &&
	    !atomic_read(&ep->rma_info.fence_refcount))
		ret = 1;
	mutex_unlock(&ep->rma_info.rma_lock);
	return ret;
}

/**
 * scif_create_pinned_pages:
 * @nr_pages: number of pages in window
 * @prot: read/write protection
 *
 * Allocate and prepare a set of pinned pages.
 */
static struct scif_pinned_pages *
scif_create_pinned_pages(int nr_pages, int prot)
{
	struct scif_pinned_pages *pin;

	might_sleep();
	pin = scif_zalloc(sizeof(*pin));
	if (!pin)
		goto error;

	pin->pages = scif_zalloc(nr_pages * sizeof(*pin->pages));
	if (!pin->pages)
		goto error_free_pinned_pages;

	pin->prot = prot;
	pin->magic = SCIFEP_MAGIC;
	return pin;

error_free_pinned_pages:
	scif_free(pin, sizeof(*pin));
error:
	return NULL;
}

/**
 * scif_destroy_pinned_pages:
 * @pin: A set of pinned pages.
 *
 * Deallocate resources for pinned pages.
 */
static int scif_destroy_pinned_pages(struct scif_pinned_pages *pin)
{
	int j;
	int writeable = pin->prot & SCIF_PROT_WRITE;
	int kernel = SCIF_MAP_KERNEL & pin->map_flags;

	for (j = 0; j < pin->nr_pages; j++) {
		if (pin->pages[j] && !kernel) {
			if (writeable)
				SetPageDirty(pin->pages[j]);
			put_page(pin->pages[j]);
		}
	}

	scif_free(pin->pages,
		  pin->nr_pages * sizeof(*pin->pages));
	scif_free(pin, sizeof(*pin));
	return 0;
}

/*
 * scif_create_window:
 * @ep: end point
 * @nr_pages: number of pages
 * @offset: registration offset
 * @temp: true if a temporary window is being created
 *
 * Allocate and prepare a self registration window.
 */
struct scif_window *scif_create_window(struct scif_endpt *ep, int nr_pages,
				       s64 offset, bool temp)
{
	struct scif_window *window;

	might_sleep();
	window = scif_zalloc(sizeof(*window));
	if (!window)
		goto error;

	window->dma_addr = scif_zalloc(nr_pages * sizeof(*window->dma_addr));
	if (!window->dma_addr)
		goto error_free_window;

	window->num_pages = scif_zalloc(nr_pages * sizeof(*window->num_pages));
	if (!window->num_pages)
		goto error_free_window;

	window->offset = offset;
	window->ep = (u64)ep;
	window->magic = SCIFEP_MAGIC;
	window->reg_state = OP_IDLE;
	init_waitqueue_head(&window->regwq);
	window->unreg_state = OP_IDLE;
	init_waitqueue_head(&window->unregwq);
	INIT_LIST_HEAD(&window->list);
	window->type = SCIF_WINDOW_SELF;
	window->temp = temp;
	return window;

error_free_window:
	scif_free(window->dma_addr,
		  nr_pages * sizeof(*window->dma_addr));
	scif_free(window, sizeof(*window));
error:
	return NULL;
}

/**
 * scif_destroy_incomplete_window:
 * @ep: end point
 * @window: registration window
 *
 * Deallocate resources for self window.
 */
static void scif_destroy_incomplete_window(struct scif_endpt *ep,
					   struct scif_window *window)
{
	int err;
	int nr_pages = window->nr_pages;
	struct scif_allocmsg *alloc = &window->alloc_handle;
	struct scifmsg msg;

retry:
	/* Wait for a SCIF_ALLOC_GNT/REJ message */
	err = wait_event_timeout(alloc->allocwq,
				 alloc->state != OP_IN_PROGRESS,
				 SCIF_NODE_ALIVE_TIMEOUT);
	if (!err && scifdev_alive(ep))
		goto retry;

	mutex_lock(&ep->rma_info.rma_lock);
	if (alloc->state == OP_COMPLETED) {
		msg.uop = SCIF_FREE_VIRT;
		msg.src = ep->port;
		msg.payload[0] = ep->remote_ep;
		msg.payload[1] = window->alloc_handle.vaddr;
		msg.payload[2] = (u64)window;
		msg.payload[3] = SCIF_REGISTER;
		_scif_nodeqp_send(ep->remote_dev, &msg);
	}
	mutex_unlock(&ep->rma_info.rma_lock);

	scif_free_window_offset(ep, window, window->offset);
	scif_free(window->dma_addr, nr_pages * sizeof(*window->dma_addr));
	scif_free(window->num_pages, nr_pages * sizeof(*window->num_pages));
	scif_free(window, sizeof(*window));
}

/**
 * scif_unmap_window:
 * @remote_dev: SCIF remote device
 * @window: registration window
 *
 * Delete any DMA mappings created for a registered self window
 */
void scif_unmap_window(struct scif_dev *remote_dev, struct scif_window *window)
{
	int j;

	if (scif_is_iommu_enabled() && !scifdev_self(remote_dev)) {
		if (window->st) {
			dma_unmap_sg(&remote_dev->sdev->dev,
				     window->st->sgl, window->st->nents,
				     DMA_BIDIRECTIONAL);
			sg_free_table(window->st);
			kfree(window->st);
			window->st = NULL;
		}
	} else {
		for (j = 0; j < window->nr_contig_chunks; j++) {
			if (window->dma_addr[j]) {
				scif_unmap_single(window->dma_addr[j],
						  remote_dev,
						  window->num_pages[j] <<
						  PAGE_SHIFT);
				window->dma_addr[j] = 0x0;
			}
		}
	}
}

static inline struct mm_struct *__scif_acquire_mm(void)
{
	if (scif_ulimit_check)
		return get_task_mm(current);
	return NULL;
}

static inline void __scif_release_mm(struct mm_struct *mm)
{
	if (mm)
		mmput(mm);
}

static inline int
__scif_dec_pinned_vm_lock(struct mm_struct *mm,
			  int nr_pages, bool try_lock)
{
	if (!mm || !nr_pages || !scif_ulimit_check)
		return 0;
	if (try_lock) {
		if (!down_write_trylock(&mm->mmap_sem)) {
			dev_err(scif_info.mdev.this_device,
				"%s %d err\n", __func__, __LINE__);
			return -1;
		}
	} else {
		down_write(&mm->mmap_sem);
	}
	mm->pinned_vm -= nr_pages;
	up_write(&mm->mmap_sem);
	return 0;
}

static inline int __scif_check_inc_pinned_vm(struct mm_struct *mm,
					     int nr_pages)
{
	unsigned long locked, lock_limit;

	if (!mm || !nr_pages || !scif_ulimit_check)
		return 0;

	locked = nr_pages;
	locked += mm->pinned_vm;
	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
	if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
		dev_err(scif_info.mdev.this_device,
			"locked(%lu) > lock_limit(%lu)\n",
			locked, lock_limit);
		return -ENOMEM;
	}
	mm->pinned_vm = locked;
	return 0;
}

/**
 * scif_destroy_window:
 * @ep: end point
 * @window: registration window
 *
 * Deallocate resources for self window.
 */
int scif_destroy_window(struct scif_endpt *ep, struct scif_window *window)
{
	int j;
	struct scif_pinned_pages *pinned_pages = window->pinned_pages;
	int nr_pages = window->nr_pages;

	might_sleep();
	if (!window->temp && window->mm) {
		__scif_dec_pinned_vm_lock(window->mm, window->nr_pages, 0);
		__scif_release_mm(window->mm);
		window->mm = NULL;
	}

	scif_free_window_offset(ep, window, window->offset);
	scif_unmap_window(ep->remote_dev, window);
	/*
	 * Decrement references for this set of pinned pages from
	 * this window.
	 */
	j = atomic_sub_return(1, &pinned_pages->ref_count);
	if (j < 0)
		dev_err(scif_info.mdev.this_device,
			"%s %d incorrect ref count %d\n",
			__func__, __LINE__, j);
	/*
	 * If the ref count for pinned_pages is zero then someone
	 * has already called scif_unpin_pages() for it and we should
	 * destroy the page cache.
	 */
	if (!j)
		scif_destroy_pinned_pages(window->pinned_pages);
	scif_free(window->dma_addr, nr_pages * sizeof(*window->dma_addr));
	scif_free(window->num_pages, nr_pages * sizeof(*window->num_pages));
	window->magic = 0;
	scif_free(window, sizeof(*window));
	return 0;
}

/**
 * scif_create_remote_lookup:
 * @remote_dev: SCIF remote device
 * @window: remote window
 *
 * Allocate and prepare lookup entries for the remote
 * end to copy over the physical addresses.
 * Returns 0 on success and appropriate errno on failure.
 */
static int scif_create_remote_lookup(struct scif_dev *remote_dev,
				     struct scif_window *window)
{
	int i, j, err = 0;
	int nr_pages = window->nr_pages;
	bool vmalloc_dma_phys, vmalloc_num_pages;

	might_sleep();
	/* Map window */
	err = scif_map_single(&window->mapped_offset,
			      window, remote_dev, sizeof(*window));
	if (err)
		goto error_window;

	/* Compute the number of lookup entries. 21 == 2MB Shift */
	window->nr_lookup = ALIGN(nr_pages * PAGE_SIZE,
					((2) * 1024 * 1024)) >> 21;

	window->dma_addr_lookup.lookup =
		scif_alloc_coherent(&window->dma_addr_lookup.offset,
				    remote_dev, window->nr_lookup *
				    sizeof(*window->dma_addr_lookup.lookup),
				    GFP_KERNEL | __GFP_ZERO);
	if (!window->dma_addr_lookup.lookup) {
		err = -ENOMEM;
		goto error_window;
	}

	window->num_pages_lookup.lookup =
		scif_alloc_coherent(&window->num_pages_lookup.offset,
				    remote_dev, window->nr_lookup *
				    sizeof(*window->num_pages_lookup.lookup),
				    GFP_KERNEL | __GFP_ZERO);
	if (!window->num_pages_lookup.lookup) {
		err = -ENOMEM;
		goto error_window;
	}

	vmalloc_dma_phys = is_vmalloc_addr(&window->dma_addr[0]);
	vmalloc_num_pages = is_vmalloc_addr(&window->num_pages[0]);

	/* Now map each of the pages containing physical addresses */
	for (i = 0, j = 0; i < nr_pages; i += SCIF_NR_ADDR_IN_PAGE, j++) {
		err = scif_map_page(&window->dma_addr_lookup.lookup[j],
				    vmalloc_dma_phys ?
				    vmalloc_to_page(&window->dma_addr[i]) :
				    virt_to_page(&window->dma_addr[i]),
				    remote_dev);
		if (err)
			goto error_window;
		err = scif_map_page(&window->num_pages_lookup.lookup[j],
				    vmalloc_dma_phys ?
				    vmalloc_to_page(&window->num_pages[i]) :
				    virt_to_page(&window->num_pages[i]),
				    remote_dev);
		if (err)
			goto error_window;
	}
	return 0;
error_window:
	return err;
}

/**
 * scif_destroy_remote_lookup:
 * @remote_dev: SCIF remote device
 * @window: remote window
 *
 * Destroy lookup entries used for the remote
 * end to copy over the physical addresses.
 */
static void scif_destroy_remote_lookup(struct scif_dev *remote_dev,
				       struct scif_window *window)
{
	int i, j;

	if (window->nr_lookup) {
		struct scif_rma_lookup *lup = &window->dma_addr_lookup;
		struct scif_rma_lookup *npup = &window->num_pages_lookup;

		for (i = 0, j = 0; i < window->nr_pages;
			i += SCIF_NR_ADDR_IN_PAGE, j++) {
			if (lup->lookup && lup->lookup[j])
				scif_unmap_single(lup->lookup[j],
						  remote_dev,
						  PAGE_SIZE);
			if (npup->lookup && npup->lookup[j])
				scif_unmap_single(npup->lookup[j],
						  remote_dev,
						  PAGE_SIZE);
		}
		if (lup->lookup)
			scif_free_coherent(lup->lookup, lup->offset,
					   remote_dev, window->nr_lookup *
					   sizeof(*lup->lookup));
		if (npup->lookup)
			scif_free_coherent(npup->lookup, npup->offset,
					   remote_dev, window->nr_lookup *
					   sizeof(*npup->lookup));
		if (window->mapped_offset)
			scif_unmap_single(window->mapped_offset,
					  remote_dev, sizeof(*window));
		window->nr_lookup = 0;
	}
}

/**
 * scif_create_remote_window:
 * @ep: end point
 * @nr_pages: number of pages in window
 *
 * Allocate and prepare a remote registration window.
 */
static struct scif_window *
scif_create_remote_window(struct scif_dev *scifdev, int nr_pages)
{
	struct scif_window *window;

	might_sleep();
	window = scif_zalloc(sizeof(*window));
	if (!window)
		goto error_ret;

	window->magic = SCIFEP_MAGIC;
	window->nr_pages = nr_pages;

	window->dma_addr = scif_zalloc(nr_pages * sizeof(*window->dma_addr));
	if (!window->dma_addr)
		goto error_window;

	window->num_pages = scif_zalloc(nr_pages *
					sizeof(*window->num_pages));
	if (!window->num_pages)
		goto error_window;

	if (scif_create_remote_lookup(scifdev, window))
		goto error_window;

	window->type = SCIF_WINDOW_PEER;
	window->unreg_state = OP_IDLE;
	INIT_LIST_HEAD(&window->list);
	return window;
error_window:
	scif_destroy_remote_window(window);
error_ret:
	return NULL;
}

/**
 * scif_destroy_remote_window:
 * @ep: end point
 * @window: remote registration window
 *
 * Deallocate resources for remote window.
 */
void
scif_destroy_remote_window(struct scif_window *window)
{
	scif_free(window->dma_addr, window->nr_pages *
		  sizeof(*window->dma_addr));
	scif_free(window->num_pages, window->nr_pages *
		  sizeof(*window->num_pages));
	window->magic = 0;
	scif_free(window, sizeof(*window));
}

/**
 * scif_iommu_map: create DMA mappings if the IOMMU is enabled
 * @remote_dev: SCIF remote device
 * @window: remote registration window
 *
 * Map the physical pages using dma_map_sg(..) and then detect the number
 * of contiguous DMA mappings allocated
 */
static int scif_iommu_map(struct scif_dev *remote_dev,
			  struct scif_window *window)
{
	struct scatterlist *sg;
	int i, err;
	scif_pinned_pages_t pin = window->pinned_pages;

	window->st = kzalloc(sizeof(*window->st), GFP_KERNEL);
	if (!window->st)
		return -ENOMEM;

	err = sg_alloc_table(window->st, window->nr_pages, GFP_KERNEL);
	if (err)
		return err;

	for_each_sg(window->st->sgl, sg, window->st->nents, i)
		sg_set_page(sg, pin->pages[i], PAGE_SIZE, 0x0);

	err = dma_map_sg(&remote_dev->sdev->dev, window->st->sgl,
			 window->st->nents, DMA_BIDIRECTIONAL);
	if (!err)
		return -ENOMEM;
	/* Detect contiguous ranges of DMA mappings */
	sg = window->st->sgl;
	for (i = 0; sg; i++) {
		dma_addr_t last_da;

		window->dma_addr[i] = sg_dma_address(sg);
		window->num_pages[i] = sg_dma_len(sg) >> PAGE_SHIFT;
		last_da = sg_dma_address(sg) + sg_dma_len(sg);
		while ((sg = sg_next(sg)) && sg_dma_address(sg) == last_da) {
			window->num_pages[i] +=
				(sg_dma_len(sg) >> PAGE_SHIFT);
			last_da = window->dma_addr[i] +
				sg_dma_len(sg);
		}
		window->nr_contig_chunks++;
	}
	return 0;
}

/**
 * scif_map_window:
 * @remote_dev: SCIF remote device
 * @window: self registration window
 *
 * Map pages of a window into the aperture/PCI.
 * Also determine addresses required for DMA.
 */
int
scif_map_window(struct scif_dev *remote_dev, struct scif_window *window)
{
	int i, j, k, err = 0, nr_contig_pages;
	scif_pinned_pages_t pin;
	phys_addr_t phys_prev, phys_curr;

	might_sleep();

	pin = window->pinned_pages;

	if (intel_iommu_enabled && !scifdev_self(remote_dev))
		return scif_iommu_map(remote_dev, window);

	for (i = 0, j = 0; i < window->nr_pages; i += nr_contig_pages, j++) {
		phys_prev = page_to_phys(pin->pages[i]);
		nr_contig_pages = 1;

		/* Detect physically contiguous chunks */
		for (k = i + 1; k < window->nr_pages; k++) {
			phys_curr = page_to_phys(pin->pages[k]);
			if (phys_curr != (phys_prev + PAGE_SIZE))
				break;
			phys_prev = phys_curr;
			nr_contig_pages++;
		}
		window->num_pages[j] = nr_contig_pages;
		window->nr_contig_chunks++;
		if (scif_is_mgmt_node()) {
			/*
			 * Management node has to deal with SMPT on X100 and
			 * hence the DMA mapping is required
			 */
			err = scif_map_single(&window->dma_addr[j],
					      phys_to_virt(page_to_phys(
							   pin->pages[i])),
					      remote_dev,
					      nr_contig_pages << PAGE_SHIFT);
			if (err)
				return err;
		} else {
			window->dma_addr[j] = page_to_phys(pin->pages[i]);
		}
	}
	return err;
}

/**
 * scif_send_scif_unregister:
 * @ep: end point
 * @window: self registration window
 *
 * Send a SCIF_UNREGISTER message.
 */
static int scif_send_scif_unregister(struct scif_endpt *ep,
				     struct scif_window *window)
{
	struct scifmsg msg;

	msg.uop = SCIF_UNREGISTER;
	msg.src = ep->port;
	msg.payload[0] = window->alloc_handle.vaddr;
	msg.payload[1] = (u64)window;
	return scif_nodeqp_send(ep->remote_dev, &msg);
}

/**
 * scif_unregister_window:
 * @window: self registration window
 *
 * Send an unregistration request and wait for a response.
 */
int scif_unregister_window(struct scif_window *window)
{
	int err = 0;
	struct scif_endpt *ep = (struct scif_endpt *)window->ep;
	bool send_msg = false;

	might_sleep();
	switch (window->unreg_state) {
	case OP_IDLE:
	{
		window->unreg_state = OP_IN_PROGRESS;
		send_msg = true;
		/* fall through */
	}
	case OP_IN_PROGRESS:
	{
		scif_get_window(window, 1);
		mutex_unlock(&ep->rma_info.rma_lock);
		if (send_msg) {
			err = scif_send_scif_unregister(ep, window);
			if (err) {
				window->unreg_state = OP_COMPLETED;
				goto done;
			}
		} else {
			/* Return ENXIO since unregistration is in progress */
			mutex_lock(&ep->rma_info.rma_lock);
			return -ENXIO;
		}
retry:
		/* Wait for a SCIF_UNREGISTER_(N)ACK message */
		err = wait_event_timeout(window->unregwq,
					 window->unreg_state != OP_IN_PROGRESS,
					 SCIF_NODE_ALIVE_TIMEOUT);
		if (!err && scifdev_alive(ep))
			goto retry;
		if (!err) {
			err = -ENODEV;
			window->unreg_state = OP_COMPLETED;
			dev_err(scif_info.mdev.this_device,
				"%s %d err %d\n", __func__, __LINE__, err);
		}
		if (err > 0)
			err = 0;
done:
		mutex_lock(&ep->rma_info.rma_lock);
		scif_put_window(window, 1);
		break;
	}
	case OP_FAILED:
	{
		if (!scifdev_alive(ep)) {
			err = -ENODEV;
			window->unreg_state = OP_COMPLETED;
		}
		break;
	}
	case OP_COMPLETED:
		break;
	default:
		err = -ENODEV;
	}

	if (window->unreg_state == OP_COMPLETED && window->ref_count)
		scif_put_window(window, window->nr_pages);

	if (!window->ref_count) {
		atomic_inc(&ep->rma_info.tw_refcount);
		list_del_init(&window->list);
		scif_free_window_offset(ep, window, window->offset);
		mutex_unlock(&ep->rma_info.rma_lock);
		if ((!!(window->pinned_pages->map_flags & SCIF_MAP_KERNEL)) &&
		    scifdev_alive(ep)) {
			scif_drain_dma_intr(ep->remote_dev->sdev,
					    ep->rma_info.dma_chan);
		} else {
			if (!__scif_dec_pinned_vm_lock(window->mm,
						       window->nr_pages, 1)) {
				__scif_release_mm(window->mm);
				window->mm = NULL;
			}
		}
		scif_queue_for_cleanup(window, &scif_info.rma);
		mutex_lock(&ep->rma_info.rma_lock);
	}
	return err;
}

/**
 * scif_send_alloc_request:
 * @ep: end point
 * @window: self registration window
 *
 * Send a remote window allocation request
 */
static int scif_send_alloc_request(struct scif_endpt *ep,
				   struct scif_window *window)
{
	struct scifmsg msg;
	struct scif_allocmsg *alloc = &window->alloc_handle;

	/* Set up the Alloc Handle */
	alloc->state = OP_IN_PROGRESS;
	init_waitqueue_head(&alloc->allocwq);

	/* Send out an allocation request */
	msg.uop = SCIF_ALLOC_REQ;
	msg.payload[1] = window->nr_pages;
	msg.payload[2] = (u64)&window->alloc_handle;
	return _scif_nodeqp_send(ep->remote_dev, &msg);
}

/**
 * scif_prep_remote_window:
 * @ep: end point
 * @window: self registration window
 *
 * Send a remote window allocation request, wait for an allocation response,
 * and prepares the remote window by copying over the page lists
 */
static int scif_prep_remote_window(struct scif_endpt *ep,
				   struct scif_window *window)
{
	struct scifmsg msg;
	struct scif_window *remote_window;
	struct scif_allocmsg *alloc = &window->alloc_handle;
	dma_addr_t *dma_phys_lookup, *tmp, *num_pages_lookup, *tmp1;
	int i = 0, j = 0;
	int nr_contig_chunks, loop_nr_contig_chunks;
	int remaining_nr_contig_chunks, nr_lookup;
	int err, map_err;

	map_err = scif_map_window(ep->remote_dev, window);
	if (map_err)
		dev_err(&ep->remote_dev->sdev->dev,
			"%s %d map_err %d\n", __func__, __LINE__, map_err);
	remaining_nr_contig_chunks = window->nr_contig_chunks;
	nr_contig_chunks = window->nr_contig_chunks;
retry:
	/* Wait for a SCIF_ALLOC_GNT/REJ message */
	err = wait_event_timeout(alloc->allocwq,
				 alloc->state != OP_IN_PROGRESS,
				 SCIF_NODE_ALIVE_TIMEOUT);
	mutex_lock(&ep->rma_info.rma_lock);
	/* Synchronize with the thread waking up allocwq */
	mutex_unlock(&ep->rma_info.rma_lock);
	if (!err && scifdev_alive(ep))
		goto retry;

	if (!err)
		err = -ENODEV;

	if (err > 0)
		err = 0;
	else
		return err;

	/* Bail out. The remote end rejected this request */
	if (alloc->state == OP_FAILED)
		return -ENOMEM;

	if (map_err) {
		dev_err(&ep->remote_dev->sdev->dev,
			"%s %d err %d\n", __func__, __LINE__, map_err);
		msg.uop = SCIF_FREE_VIRT;
		msg.src = ep->port;
		msg.payload[0] = ep->remote_ep;
		msg.payload[1] = window->alloc_handle.vaddr;
		msg.payload[2] = (u64)window;
		msg.payload[3] = SCIF_REGISTER;
		spin_lock(&ep->lock);
		if (ep->state == SCIFEP_CONNECTED)
			err = _scif_nodeqp_send(ep->remote_dev, &msg);
		else
			err = -ENOTCONN;
		spin_unlock(&ep->lock);
		return err;
	}

	remote_window = scif_ioremap(alloc->phys_addr, sizeof(*window),
				     ep->remote_dev);

	/* Compute the number of lookup entries. 21 == 2MB Shift */
	nr_lookup = ALIGN(nr_contig_chunks, SCIF_NR_ADDR_IN_PAGE)
			  >> ilog2(SCIF_NR_ADDR_IN_PAGE);

	dma_phys_lookup =
		scif_ioremap(remote_window->dma_addr_lookup.offset,
			     nr_lookup *
			     sizeof(*remote_window->dma_addr_lookup.lookup),
			     ep->remote_dev);
	num_pages_lookup =
		scif_ioremap(remote_window->num_pages_lookup.offset,
			     nr_lookup *
			     sizeof(*remote_window->num_pages_lookup.lookup),
			     ep->remote_dev);

	while (remaining_nr_contig_chunks) {
		loop_nr_contig_chunks = min_t(int, remaining_nr_contig_chunks,
					      (int)SCIF_NR_ADDR_IN_PAGE);
		/* #1/2 - Copy  physical addresses over to the remote side */

		/* #2/2 - Copy DMA addresses (addresses that are fed into the
		 * DMA engine) We transfer bus addresses which are then
		 * converted into a MIC physical address on the remote
		 * side if it is a MIC, if the remote node is a mgmt node we
		 * transfer the MIC physical address
		 */
		tmp = scif_ioremap(dma_phys_lookup[j],
				   loop_nr_contig_chunks *
				   sizeof(*window->dma_addr),
				   ep->remote_dev);
		tmp1 = scif_ioremap(num_pages_lookup[j],
				    loop_nr_contig_chunks *
				    sizeof(*window->num_pages),
				    ep->remote_dev);
		if (scif_is_mgmt_node()) {
			memcpy_toio((void __force __iomem *)tmp,
				    &window->dma_addr[i], loop_nr_contig_chunks
				    * sizeof(*window->dma_addr));
			memcpy_toio((void __force __iomem *)tmp1,
				    &window->num_pages[i], loop_nr_contig_chunks
				    * sizeof(*window->num_pages));
		} else {
			if (scifdev_is_p2p(ep->remote_dev)) {
				/*
				 * add remote node's base address for this node
				 * to convert it into a MIC address
				 */
				int m;
				dma_addr_t dma_addr;

				for (m = 0; m < loop_nr_contig_chunks; m++) {
					dma_addr = window->dma_addr[i + m] +
						ep->remote_dev->base_addr;
					writeq(dma_addr,
					       (void __force __iomem *)&tmp[m]);
				}
				memcpy_toio((void __force __iomem *)tmp1,
					    &window->num_pages[i],
					    loop_nr_contig_chunks
					    * sizeof(*window->num_pages));
			} else {
				/* Mgmt node or loopback - transfer DMA
				 * addresses as is, this is the same as a
				 * MIC physical address (we use the dma_addr
				 * and not the phys_addr array since the
				 * phys_addr is only setup if there is a mmap()
				 * request from the mgmt node)
				 */
				memcpy_toio((void __force __iomem *)tmp,
					    &window->dma_addr[i],
					    loop_nr_contig_chunks *
					    sizeof(*window->dma_addr));
				memcpy_toio((void __force __iomem *)tmp1,
					    &window->num_pages[i],
					    loop_nr_contig_chunks *
					    sizeof(*window->num_pages));
			}
		}
		remaining_nr_contig_chunks -= loop_nr_contig_chunks;
		i += loop_nr_contig_chunks;
		j++;
		scif_iounmap(tmp, loop_nr_contig_chunks *
			     sizeof(*window->dma_addr), ep->remote_dev);
		scif_iounmap(tmp1, loop_nr_contig_chunks *
			     sizeof(*window->num_pages), ep->remote_dev);
	}

	/* Prepare the remote window for the peer */
	remote_window->peer_window = (u64)window;
	remote_window->offset = window->offset;
	remote_window->prot = window->prot;
	remote_window->nr_contig_chunks = nr_contig_chunks;
	remote_window->ep = ep->remote_ep;
	scif_iounmap(num_pages_lookup,
		     nr_lookup *
		     sizeof(*remote_window->num_pages_lookup.lookup),
		     ep->remote_dev);
	scif_iounmap(dma_phys_lookup,
		     nr_lookup *
		     sizeof(*remote_window->dma_addr_lookup.lookup),
		     ep->remote_dev);
	scif_iounmap(remote_window, sizeof(*remote_window), ep->remote_dev);
	window->peer_window = alloc->vaddr;
	return err;
}

/**
 * scif_send_scif_register:
 * @ep: end point
 * @window: self registration window
 *
 * Send a SCIF_REGISTER message if EP is connected and wait for a
 * SCIF_REGISTER_(N)ACK message else send a SCIF_FREE_VIRT
 * message so that the peer can free its remote window allocated earlier.
 */
static int scif_send_scif_register(struct scif_endpt *ep,
				   struct scif_window *window)
{
	int err = 0;
	struct scifmsg msg;

	msg.src = ep->port;
	msg.payload[0] = ep->remote_ep;
	msg.payload[1] = window->alloc_handle.vaddr;
	msg.payload[2] = (u64)window;
	spin_lock(&ep->lock);
	if (ep->state == SCIFEP_CONNECTED) {
		msg.uop = SCIF_REGISTER;
		window->reg_state = OP_IN_PROGRESS;
		err = _scif_nodeqp_send(ep->remote_dev, &msg);
		spin_unlock(&ep->lock);
		if (!err) {
retry:
			/* Wait for a SCIF_REGISTER_(N)ACK message */
			err = wait_event_timeout(window->regwq,
						 window->reg_state !=
						 OP_IN_PROGRESS,
						 SCIF_NODE_ALIVE_TIMEOUT);
			if (!err && scifdev_alive(ep))
				goto retry;
			err = !err ? -ENODEV : 0;
			if (window->reg_state == OP_FAILED)
				err = -ENOTCONN;
		}
	} else {
		msg.uop = SCIF_FREE_VIRT;
		msg.payload[3] = SCIF_REGISTER;
		err = _scif_nodeqp_send(ep->remote_dev, &msg);
		spin_unlock(&ep->lock);
		if (!err)
			err = -ENOTCONN;
	}
	return err;
}

/**
 * scif_get_window_offset:
 * @ep: end point descriptor
 * @flags: flags
 * @offset: offset hint
 * @num_pages: number of pages
 * @out_offset: computed offset returned by reference.
 *
 * Compute/Claim a new offset for this EP.
 */
int scif_get_window_offset(struct scif_endpt *ep, int flags, s64 offset,
			   int num_pages, s64 *out_offset)
{
	s64 page_index;
	struct iova *iova_ptr;
	int err = 0;

	if (flags & SCIF_MAP_FIXED) {
		page_index = SCIF_IOVA_PFN(offset);
		iova_ptr = reserve_iova(&ep->rma_info.iovad, page_index,
					page_index + num_pages - 1);
		if (!iova_ptr)
			err = -EADDRINUSE;
	} else {
		iova_ptr = alloc_iova(&ep->rma_info.iovad, num_pages,
				      SCIF_DMA_63BIT_PFN - 1, 0);
		if (!iova_ptr)
			err = -ENOMEM;
	}
	if (!err)
		*out_offset = (iova_ptr->pfn_lo) << PAGE_SHIFT;
	return err;
}

/**
 * scif_free_window_offset:
 * @ep: end point descriptor
 * @window: registration window
 * @offset: Offset to be freed
 *
 * Free offset for this EP. The callee is supposed to grab
 * the RMA mutex before calling this API.
 */
void scif_free_window_offset(struct scif_endpt *ep,
			     struct scif_window *window, s64 offset)
{
	if ((window && !window->offset_freed) || !window) {
		free_iova(&ep->rma_info.iovad, offset >> PAGE_SHIFT);
		if (window)
			window->offset_freed = true;
	}
}

/**
 * scif_alloc_req: Respond to SCIF_ALLOC_REQ interrupt message
 * @msg:        Interrupt message
 *
 * Remote side is requesting a memory allocation.
 */
void scif_alloc_req(struct scif_dev *scifdev, struct scifmsg *msg)
{
	int err;
	struct scif_window *window = NULL;
	int nr_pages = msg->payload[1];

	window = scif_create_remote_window(scifdev, nr_pages);
	if (!window) {
		err = -ENOMEM;
		goto error;
	}

	/* The peer's allocation request is granted */
	msg->uop = SCIF_ALLOC_GNT;
	msg->payload[0] = (u64)window;
	msg->payload[1] = window->mapped_offset;
	err = scif_nodeqp_send(scifdev, msg);
	if (err)
		scif_destroy_remote_window(window);
	return;
error:
	/* The peer's allocation request is rejected */
	dev_err(&scifdev->sdev->dev,
		"%s %d error %d alloc_ptr %p nr_pages 0x%x\n",
		__func__, __LINE__, err, window, nr_pages);
	msg->uop = SCIF_ALLOC_REJ;
	scif_nodeqp_send(scifdev, msg);
}

/**
 * scif_alloc_gnt_rej: Respond to SCIF_ALLOC_GNT/REJ interrupt message
 * @msg:        Interrupt message
 *
 * Remote side responded to a memory allocation.
 */
void scif_alloc_gnt_rej(struct scif_dev *scifdev, struct scifmsg *msg)
{
	struct scif_allocmsg *handle = (struct scif_allocmsg *)msg->payload[2];
	struct scif_window *window = container_of(handle, struct scif_window,
						  alloc_handle);
	struct scif_endpt *ep = (struct scif_endpt *)window->ep;

	mutex_lock(&ep->rma_info.rma_lock);
	handle->vaddr = msg->payload[0];
	handle->phys_addr = msg->payload[1];
	if (msg->uop == SCIF_ALLOC_GNT)
		handle->state = OP_COMPLETED;
	else
		handle->state = OP_FAILED;
	wake_up(&handle->allocwq);
	mutex_unlock(&ep->rma_info.rma_lock);
}

/**
 * scif_free_virt: Respond to SCIF_FREE_VIRT interrupt message
 * @msg:        Interrupt message
 *
 * Free up memory kmalloc'd earlier.
 */
void scif_free_virt(struct scif_dev *scifdev, struct scifmsg *msg)
{
	struct scif_window *window = (struct scif_window *)msg->payload[1];

	scif_destroy_remote_window(window);
}

static void
scif_fixup_aper_base(struct scif_dev *dev, struct scif_window *window)
{
	int j;
	struct scif_hw_dev *sdev = dev->sdev;
	phys_addr_t apt_base = 0;

	/*
	 * Add the aperture base if the DMA address is not card relative
	 * since the DMA addresses need to be an offset into the bar
	 */
	if (!scifdev_self(dev) && window->type == SCIF_WINDOW_PEER &&
	    sdev->aper && !sdev->card_rel_da)
		apt_base = sdev->aper->pa;
	else
		return;

	for (j = 0; j < window->nr_contig_chunks; j++) {
		if (window->num_pages[j])
			window->dma_addr[j] += apt_base;
		else
			break;
	}
}

/**
 * scif_recv_reg: Respond to SCIF_REGISTER interrupt message
 * @msg:        Interrupt message
 *
 * Update remote window list with a new registered window.
 */
void scif_recv_reg(struct scif_dev *scifdev, struct scifmsg *msg)
{
	struct scif_endpt *ep = (struct scif_endpt *)msg->payload[0];
	struct scif_window *window =
		(struct scif_window *)msg->payload[1];

	mutex_lock(&ep->rma_info.rma_lock);
	spin_lock(&ep->lock);
	if (ep->state == SCIFEP_CONNECTED) {
		msg->uop = SCIF_REGISTER_ACK;
		scif_nodeqp_send(ep->remote_dev, msg);
		scif_fixup_aper_base(ep->remote_dev, window);
		/* No further failures expected. Insert new window */
		scif_insert_window(window, &ep->rma_info.remote_reg_list);
	} else {
		msg->uop = SCIF_REGISTER_NACK;
		scif_nodeqp_send(ep->remote_dev, msg);
	}
	spin_unlock(&ep->lock);
	mutex_unlock(&ep->rma_info.rma_lock);
	/* free up any lookup resources now that page lists are transferred */
	scif_destroy_remote_lookup(ep->remote_dev, window);
	/*
	 * We could not insert the window but we need to
	 * destroy the window.
	 */
	if (msg->uop == SCIF_REGISTER_NACK)
		scif_destroy_remote_window(window);
}

/**
 * scif_recv_unreg: Respond to SCIF_UNREGISTER interrupt message
 * @msg:        Interrupt message
 *
 * Remove window from remote registration list;
 */
void scif_recv_unreg(struct scif_dev *scifdev, struct scifmsg *msg)
{
	struct scif_rma_req req;
	struct scif_window *window = NULL;
	struct scif_window *recv_window =
		(struct scif_window *)msg->payload[0];
	struct scif_endpt *ep;
	int del_window = 0;

	ep = (struct scif_endpt *)recv_window->ep;
	req.out_window = &window;
	req.offset = recv_window->offset;
	req.prot = 0;
	req.nr_bytes = recv_window->nr_pages << PAGE_SHIFT;
	req.type = SCIF_WINDOW_FULL;
	req.head = &ep->rma_info.remote_reg_list;
	msg->payload[0] = ep->remote_ep;

	mutex_lock(&ep->rma_info.rma_lock);
	/* Does a valid window exist? */
	if (scif_query_window(&req)) {
		dev_err(&scifdev->sdev->dev,
			"%s %d -ENXIO\n", __func__, __LINE__);
		msg->uop = SCIF_UNREGISTER_ACK;
		goto error;
	}
	if (window) {
		if (window->ref_count)
			scif_put_window(window, window->nr_pages);
		else
			dev_err(&scifdev->sdev->dev,
				"%s %d ref count should be +ve\n",
				__func__, __LINE__);
		window->unreg_state = OP_COMPLETED;
		if (!window->ref_count) {
			msg->uop = SCIF_UNREGISTER_ACK;
			atomic_inc(&ep->rma_info.tw_refcount);
			ep->rma_info.async_list_del = 1;
			list_del_init(&window->list);
			del_window = 1;
		} else {
			/* NACK! There are valid references to this window */
			msg->uop = SCIF_UNREGISTER_NACK;
		}
	} else {
		/* The window did not make its way to the list at all. ACK */
		msg->uop = SCIF_UNREGISTER_ACK;
		scif_destroy_remote_window(recv_window);
	}
error:
	mutex_unlock(&ep->rma_info.rma_lock);
	if (del_window)
		scif_drain_dma_intr(ep->remote_dev->sdev,
				    ep->rma_info.dma_chan);
	scif_nodeqp_send(ep->remote_dev, msg);
	if (del_window)
		scif_queue_for_cleanup(window, &scif_info.rma);
}

/**
 * scif_recv_reg_ack: Respond to SCIF_REGISTER_ACK interrupt message
 * @msg:        Interrupt message
 *
 * Wake up the window waiting to complete registration.
 */
void scif_recv_reg_ack(struct scif_dev *scifdev, struct scifmsg *msg)
{
	struct scif_window *window =
		(struct scif_window *)msg->payload[2];
	struct scif_endpt *ep = (struct scif_endpt *)window->ep;

	mutex_lock(&ep->rma_info.rma_lock);
	window->reg_state = OP_COMPLETED;
	wake_up(&window->regwq);
	mutex_unlock(&ep->rma_info.rma_lock);
}

/**
 * scif_recv_reg_nack: Respond to SCIF_REGISTER_NACK interrupt message
 * @msg:        Interrupt message
 *
 * Wake up the window waiting to inform it that registration
 * cannot be completed.
 */
void scif_recv_reg_nack(struct scif_dev *scifdev, struct scifmsg *msg)
{
	struct scif_window *window =
		(struct scif_window *)msg->payload[2];
	struct scif_endpt *ep = (struct scif_endpt *)window->ep;

	mutex_lock(&ep->rma_info.rma_lock);
	window->reg_state = OP_FAILED;
	wake_up(&window->regwq);
	mutex_unlock(&ep->rma_info.rma_lock);
}

/**
 * scif_recv_unreg_ack: Respond to SCIF_UNREGISTER_ACK interrupt message
 * @msg:        Interrupt message
 *
 * Wake up the window waiting to complete unregistration.
 */
void scif_recv_unreg_ack(struct scif_dev *scifdev, struct scifmsg *msg)
{
	struct scif_window *window =
		(struct scif_window *)msg->payload[1];
	struct scif_endpt *ep = (struct scif_endpt *)window->ep;

	mutex_lock(&ep->rma_info.rma_lock);
	window->unreg_state = OP_COMPLETED;
	wake_up(&window->unregwq);
	mutex_unlock(&ep->rma_info.rma_lock);
}

/**
 * scif_recv_unreg_nack: Respond to SCIF_UNREGISTER_NACK interrupt message
 * @msg:        Interrupt message
 *
 * Wake up the window waiting to inform it that unregistration
 * cannot be completed immediately.
 */
void scif_recv_unreg_nack(struct scif_dev *scifdev, struct scifmsg *msg)
{
	struct scif_window *window =
		(struct scif_window *)msg->payload[1];
	struct scif_endpt *ep = (struct scif_endpt *)window->ep;

	mutex_lock(&ep->rma_info.rma_lock);
	window->unreg_state = OP_FAILED;
	wake_up(&window->unregwq);
	mutex_unlock(&ep->rma_info.rma_lock);
}

int __scif_pin_pages(void *addr, size_t len, int *out_prot,
		     int map_flags, scif_pinned_pages_t *pages)
{
	struct scif_pinned_pages *pinned_pages;
	int nr_pages, err = 0, i;
	bool vmalloc_addr = false;
	bool try_upgrade = false;
	int prot = *out_prot;
	int ulimit = 0;
	struct mm_struct *mm = NULL;

	/* Unsupported flags */
	if (map_flags & ~(SCIF_MAP_KERNEL | SCIF_MAP_ULIMIT))
		return -EINVAL;
	ulimit = !!(map_flags & SCIF_MAP_ULIMIT);

	/* Unsupported protection requested */
	if (prot & ~(SCIF_PROT_READ | SCIF_PROT_WRITE))
		return -EINVAL;

	/* addr/len must be page aligned. len should be non zero */
	if (!len ||
	    (ALIGN((u64)addr, PAGE_SIZE) != (u64)addr) ||
	    (ALIGN((u64)len, PAGE_SIZE) != (u64)len))
		return -EINVAL;

	might_sleep();

	nr_pages = len >> PAGE_SHIFT;

	/* Allocate a set of pinned pages */
	pinned_pages = scif_create_pinned_pages(nr_pages, prot);
	if (!pinned_pages)
		return -ENOMEM;

	if (map_flags & SCIF_MAP_KERNEL) {
		if (is_vmalloc_addr(addr))
			vmalloc_addr = true;

		for (i = 0; i < nr_pages; i++) {
			if (vmalloc_addr)
				pinned_pages->pages[i] =
					vmalloc_to_page(addr + (i * PAGE_SIZE));
			else
				pinned_pages->pages[i] =
					virt_to_page(addr + (i * PAGE_SIZE));
		}
		pinned_pages->nr_pages = nr_pages;
		pinned_pages->map_flags = SCIF_MAP_KERNEL;
	} else {
		/*
		 * SCIF supports registration caching. If a registration has
		 * been requested with read only permissions, then we try
		 * to pin the pages with RW permissions so that a subsequent
		 * transfer with RW permission can hit the cache instead of
		 * invalidating it. If the upgrade fails with RW then we
		 * revert back to R permission and retry
		 */
		if (prot == SCIF_PROT_READ)
			try_upgrade = true;
		prot |= SCIF_PROT_WRITE;
retry:
		mm = current->mm;
		down_write(&mm->mmap_sem);
		if (ulimit) {
			err = __scif_check_inc_pinned_vm(mm, nr_pages);
			if (err) {
				up_write(&mm->mmap_sem);
				pinned_pages->nr_pages = 0;
				goto error_unmap;
			}
		}

		pinned_pages->nr_pages = get_user_pages(
				(u64)addr,
				nr_pages,
				(prot & SCIF_PROT_WRITE) ? FOLL_WRITE : 0,
				pinned_pages->pages,
				NULL);
		up_write(&mm->mmap_sem);
		if (nr_pages != pinned_pages->nr_pages) {
			if (try_upgrade) {
				if (ulimit)
					__scif_dec_pinned_vm_lock(mm,
								  nr_pages, 0);
				/* Roll back any pinned pages */
				for (i = 0; i < pinned_pages->nr_pages; i++) {
					if (pinned_pages->pages[i])
						put_page(
						pinned_pages->pages[i]);
				}
				prot &= ~SCIF_PROT_WRITE;
				try_upgrade = false;
				goto retry;
			}
		}
		pinned_pages->map_flags = 0;
	}

	if (pinned_pages->nr_pages < nr_pages) {
		err = -EFAULT;
		pinned_pages->nr_pages = nr_pages;
		goto dec_pinned;
	}

	*out_prot = prot;
	atomic_set(&pinned_pages->ref_count, 1);
	*pages = pinned_pages;
	return err;
dec_pinned:
	if (ulimit)
		__scif_dec_pinned_vm_lock(mm, nr_pages, 0);
	/* Something went wrong! Rollback */
error_unmap:
	pinned_pages->nr_pages = nr_pages;
	scif_destroy_pinned_pages(pinned_pages);
	*pages = NULL;
	dev_dbg(scif_info.mdev.this_device,
		"%s %d err %d len 0x%lx\n", __func__, __LINE__, err, len);
	return err;
}

int scif_pin_pages(void *addr, size_t len, int prot,
		   int map_flags, scif_pinned_pages_t *pages)
{
	return __scif_pin_pages(addr, len, &prot, map_flags, pages);
}
EXPORT_SYMBOL_GPL(scif_pin_pages);

int scif_unpin_pages(scif_pinned_pages_t pinned_pages)
{
	int err = 0, ret;

	if (!pinned_pages || SCIFEP_MAGIC != pinned_pages->magic)
		return -EINVAL;

	ret = atomic_sub_return(1, &pinned_pages->ref_count);
	if (ret < 0) {
		dev_err(scif_info.mdev.this_device,
			"%s %d scif_unpin_pages called without pinning? rc %d\n",
			__func__, __LINE__, ret);
		return -EINVAL;
	}
	/*
	 * Destroy the window if the ref count for this set of pinned
	 * pages has dropped to zero. If it is positive then there is
	 * a valid registered window which is backed by these pages and
	 * it will be destroyed once all such windows are unregistered.
	 */
	if (!ret)
		err = scif_destroy_pinned_pages(pinned_pages);

	return err;
}
EXPORT_SYMBOL_GPL(scif_unpin_pages);

static inline void
scif_insert_local_window(struct scif_window *window, struct scif_endpt *ep)
{
	mutex_lock(&ep->rma_info.rma_lock);
	scif_insert_window(window, &ep->rma_info.reg_list);
	mutex_unlock(&ep->rma_info.rma_lock);
}

off_t scif_register_pinned_pages(scif_epd_t epd,
				 scif_pinned_pages_t pinned_pages,
				 off_t offset, int map_flags)
{
	struct scif_endpt *ep = (struct scif_endpt *)epd;
	s64 computed_offset;
	struct scif_window *window;
	int err;
	size_t len;
	struct device *spdev;

	/* Unsupported flags */
	if (map_flags & ~SCIF_MAP_FIXED)
		return -EINVAL;

	len = pinned_pages->nr_pages << PAGE_SHIFT;

	/*
	 * Offset is not page aligned/negative or offset+len
	 * wraps around with SCIF_MAP_FIXED.
	 */
	if ((map_flags & SCIF_MAP_FIXED) &&
	    ((ALIGN(offset, PAGE_SIZE) != offset) ||
	    (offset < 0) ||
	    (len > LONG_MAX - offset)))
		return -EINVAL;

	might_sleep();

	err = scif_verify_epd(ep);
	if (err)
		return err;
	/*
	 * It is an error to pass pinned_pages to scif_register_pinned_pages()
	 * after calling scif_unpin_pages().
	 */
	if (!atomic_add_unless(&pinned_pages->ref_count, 1, 0))
		return -EINVAL;

	/* Compute the offset for this registration */
	err = scif_get_window_offset(ep, map_flags, offset,
				     len, &computed_offset);
	if (err) {
		atomic_sub(1, &pinned_pages->ref_count);
		return err;
	}

	/* Allocate and prepare self registration window */
	window = scif_create_window(ep, pinned_pages->nr_pages,
				    computed_offset, false);
	if (!window) {
		atomic_sub(1, &pinned_pages->ref_count);
		scif_free_window_offset(ep, NULL, computed_offset);
		return -ENOMEM;
	}

	window->pinned_pages = pinned_pages;
	window->nr_pages = pinned_pages->nr_pages;
	window->prot = pinned_pages->prot;

	spdev = scif_get_peer_dev(ep->remote_dev);
	if (IS_ERR(spdev)) {
		err = PTR_ERR(spdev);
		scif_destroy_window(ep, window);
		return err;
	}
	err = scif_send_alloc_request(ep, window);
	if (err) {
		dev_err(&ep->remote_dev->sdev->dev,
			"%s %d err %d\n", __func__, __LINE__, err);
		goto error_unmap;
	}

	/* Prepare the remote registration window */
	err = scif_prep_remote_window(ep, window);
	if (err) {
		dev_err(&ep->remote_dev->sdev->dev,
			"%s %d err %d\n", __func__, __LINE__, err);
		goto error_unmap;
	}

	/* Tell the peer about the new window */
	err = scif_send_scif_register(ep, window);
	if (err) {
		dev_err(&ep->remote_dev->sdev->dev,
			"%s %d err %d\n", __func__, __LINE__, err);
		goto error_unmap;
	}

	scif_put_peer_dev(spdev);
	/* No further failures expected. Insert new window */
	scif_insert_local_window(window, ep);
	return computed_offset;
error_unmap:
	scif_destroy_window(ep, window);
	scif_put_peer_dev(spdev);
	dev_err(&ep->remote_dev->sdev->dev,
		"%s %d err %d\n", __func__, __LINE__, err);
	return err;
}
EXPORT_SYMBOL_GPL(scif_register_pinned_pages);

off_t scif_register(scif_epd_t epd, void *addr, size_t len, off_t offset,
		    int prot, int map_flags)
{
	scif_pinned_pages_t pinned_pages;
	off_t err;
	struct scif_endpt *ep = (struct scif_endpt *)epd;
	s64 computed_offset;
	struct scif_window *window;
	struct mm_struct *mm = NULL;
	struct device *spdev;

	dev_dbg(scif_info.mdev.this_device,
		"SCIFAPI register: ep %p addr %p len 0x%lx offset 0x%lx prot 0x%x map_flags 0x%x\n",
		epd, addr, len, offset, prot, map_flags);
	/* Unsupported flags */
	if (map_flags & ~(SCIF_MAP_FIXED | SCIF_MAP_KERNEL))
		return -EINVAL;

	/*
	 * Offset is not page aligned/negative or offset+len
	 * wraps around with SCIF_MAP_FIXED.
	 */
	if ((map_flags & SCIF_MAP_FIXED) &&
	    ((ALIGN(offset, PAGE_SIZE) != offset) ||
	    (offset < 0) ||
	    (len > LONG_MAX - offset)))
		return -EINVAL;

	/* Unsupported protection requested */
	if (prot & ~(SCIF_PROT_READ | SCIF_PROT_WRITE))
		return -EINVAL;

	/* addr/len must be page aligned. len should be non zero */
	if (!len || (ALIGN((u64)addr, PAGE_SIZE) != (u64)addr) ||
	    (ALIGN(len, PAGE_SIZE) != len))
		return -EINVAL;

	might_sleep();

	err = scif_verify_epd(ep);
	if (err)
		return err;

	/* Compute the offset for this registration */
	err = scif_get_window_offset(ep, map_flags, offset,
				     len >> PAGE_SHIFT, &computed_offset);
	if (err)
		return err;

	spdev = scif_get_peer_dev(ep->remote_dev);
	if (IS_ERR(spdev)) {
		err = PTR_ERR(spdev);
		scif_free_window_offset(ep, NULL, computed_offset);
		return err;
	}
	/* Allocate and prepare self registration window */
	window = scif_create_window(ep, len >> PAGE_SHIFT,
				    computed_offset, false);
	if (!window) {
		scif_free_window_offset(ep, NULL, computed_offset);
		scif_put_peer_dev(spdev);
		return -ENOMEM;
	}

	window->nr_pages = len >> PAGE_SHIFT;

	err = scif_send_alloc_request(ep, window);
	if (err) {
		scif_destroy_incomplete_window(ep, window);
		scif_put_peer_dev(spdev);
		return err;
	}

	if (!(map_flags & SCIF_MAP_KERNEL)) {
		mm = __scif_acquire_mm();
		map_flags |= SCIF_MAP_ULIMIT;
	}
	/* Pin down the pages */
	err = __scif_pin_pages(addr, len, &prot,
			       map_flags & (SCIF_MAP_KERNEL | SCIF_MAP_ULIMIT),
			       &pinned_pages);
	if (err) {
		scif_destroy_incomplete_window(ep, window);
		__scif_release_mm(mm);
		goto error;
	}

	window->pinned_pages = pinned_pages;
	window->prot = pinned_pages->prot;
	window->mm = mm;

	/* Prepare the remote registration window */
	err = scif_prep_remote_window(ep, window);
	if (err) {
		dev_err(&ep->remote_dev->sdev->dev,
			"%s %d err %ld\n", __func__, __LINE__, err);
		goto error_unmap;
	}

	/* Tell the peer about the new window */
	err = scif_send_scif_register(ep, window);
	if (err) {
		dev_err(&ep->remote_dev->sdev->dev,
			"%s %d err %ld\n", __func__, __LINE__, err);
		goto error_unmap;
	}

	scif_put_peer_dev(spdev);
	/* No further failures expected. Insert new window */
	scif_insert_local_window(window, ep);
	dev_dbg(&ep->remote_dev->sdev->dev,
		"SCIFAPI register: ep %p addr %p len 0x%lx computed_offset 0x%llx\n",
		epd, addr, len, computed_offset);
	return computed_offset;
error_unmap:
	scif_destroy_window(ep, window);
error:
	scif_put_peer_dev(spdev);
	dev_err(&ep->remote_dev->sdev->dev,
		"%s %d err %ld\n", __func__, __LINE__, err);
	return err;
}
EXPORT_SYMBOL_GPL(scif_register);

int
scif_unregister(scif_epd_t epd, off_t offset, size_t len)
{
	struct scif_endpt *ep = (struct scif_endpt *)epd;
	struct scif_window *window = NULL;
	struct scif_rma_req req;
	int nr_pages, err;
	struct device *spdev;

	dev_dbg(scif_info.mdev.this_device,
		"SCIFAPI unregister: ep %p offset 0x%lx len 0x%lx\n",
		ep, offset, len);
	/* len must be page aligned. len should be non zero */
	if (!len ||
	    (ALIGN((u64)len, PAGE_SIZE) != (u64)len))
		return -EINVAL;

	/* Offset is not page aligned or offset+len wraps around */
	if ((ALIGN(offset, PAGE_SIZE) != offset) ||
	    (offset < 0) ||
	    (len > LONG_MAX - offset))
		return -EINVAL;

	err = scif_verify_epd(ep);
	if (err)
		return err;

	might_sleep();
	nr_pages = len >> PAGE_SHIFT;

	req.out_window = &window;
	req.offset = offset;
	req.prot = 0;
	req.nr_bytes = len;
	req.type = SCIF_WINDOW_FULL;
	req.head = &ep->rma_info.reg_list;

	spdev = scif_get_peer_dev(ep->remote_dev);
	if (IS_ERR(spdev)) {
		err = PTR_ERR(spdev);
		return err;
	}
	mutex_lock(&ep->rma_info.rma_lock);
	/* Does a valid window exist? */
	err = scif_query_window(&req);
	if (err) {
		dev_err(&ep->remote_dev->sdev->dev,
			"%s %d err %d\n", __func__, __LINE__, err);
		goto error;
	}
	/* Unregister all the windows in this range */
	err = scif_rma_list_unregister(window, offset, nr_pages);
	if (err)
		dev_err(&ep->remote_dev->sdev->dev,
			"%s %d err %d\n", __func__, __LINE__, err);
error:
	mutex_unlock(&ep->rma_info.rma_lock);
	scif_put_peer_dev(spdev);
	return err;
}
EXPORT_SYMBOL_GPL(scif_unregister);