summaryrefslogtreecommitdiffstats
path: root/drivers/misc/mic/vop/vop_vringh.c
blob: e94c7fb6712aab35a1a3278241c3bab494f68777 (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
/*
 * Intel MIC Platform Software Stack (MPSS)
 *
 * Copyright(c) 2016 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.
 *
 * The full GNU General Public License is included in this distribution in
 * the file called "COPYING".
 *
 * Intel Virtio Over PCIe (VOP) driver.
 *
 */
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/dma-mapping.h>

#include <linux/mic_common.h>
#include "../common/mic_dev.h"

#include <linux/mic_ioctl.h>
#include "vop_main.h"

/* Helper API to obtain the VOP PCIe device */
static inline struct device *vop_dev(struct vop_vdev *vdev)
{
	return vdev->vpdev->dev.parent;
}

/* Helper API to check if a virtio device is initialized */
static inline int vop_vdev_inited(struct vop_vdev *vdev)
{
	if (!vdev)
		return -EINVAL;
	/* Device has not been created yet */
	if (!vdev->dd || !vdev->dd->type) {
		dev_err(vop_dev(vdev), "%s %d err %d\n",
			__func__, __LINE__, -EINVAL);
		return -EINVAL;
	}
	/* Device has been removed/deleted */
	if (vdev->dd->type == -1) {
		dev_dbg(vop_dev(vdev), "%s %d err %d\n",
			__func__, __LINE__, -ENODEV);
		return -ENODEV;
	}
	return 0;
}

static void _vop_notify(struct vringh *vrh)
{
	struct vop_vringh *vvrh = container_of(vrh, struct vop_vringh, vrh);
	struct vop_vdev *vdev = vvrh->vdev;
	struct vop_device *vpdev = vdev->vpdev;
	s8 db = vdev->dc->h2c_vdev_db;

	if (db != -1)
		vpdev->hw_ops->send_intr(vpdev, db);
}

static void vop_virtio_init_post(struct vop_vdev *vdev)
{
	struct mic_vqconfig *vqconfig = mic_vq_config(vdev->dd);
	struct vop_device *vpdev = vdev->vpdev;
	int i, used_size;

	for (i = 0; i < vdev->dd->num_vq; i++) {
		used_size = PAGE_ALIGN(sizeof(u16) * 3 +
				sizeof(struct vring_used_elem) *
				le16_to_cpu(vqconfig->num));
		if (!le64_to_cpu(vqconfig[i].used_address)) {
			dev_warn(vop_dev(vdev), "used_address zero??\n");
			continue;
		}
		vdev->vvr[i].vrh.vring.used =
			(void __force *)vpdev->hw_ops->ioremap(
			vpdev,
			le64_to_cpu(vqconfig[i].used_address),
			used_size);
	}

	vdev->dc->used_address_updated = 0;

	dev_info(vop_dev(vdev), "%s: device type %d LINKUP\n",
		 __func__, vdev->virtio_id);
}

static inline void vop_virtio_device_reset(struct vop_vdev *vdev)
{
	int i;

	dev_dbg(vop_dev(vdev), "%s: status %d device type %d RESET\n",
		__func__, vdev->dd->status, vdev->virtio_id);

	for (i = 0; i < vdev->dd->num_vq; i++)
		/*
		 * Avoid lockdep false positive. The + 1 is for the vop
		 * mutex which is held in the reset devices code path.
		 */
		mutex_lock_nested(&vdev->vvr[i].vr_mutex, i + 1);

	/* 0 status means "reset" */
	vdev->dd->status = 0;
	vdev->dc->vdev_reset = 0;
	vdev->dc->host_ack = 1;

	for (i = 0; i < vdev->dd->num_vq; i++) {
		struct vringh *vrh = &vdev->vvr[i].vrh;

		vdev->vvr[i].vring.info->avail_idx = 0;
		vrh->completed = 0;
		vrh->last_avail_idx = 0;
		vrh->last_used_idx = 0;
	}

	for (i = 0; i < vdev->dd->num_vq; i++)
		mutex_unlock(&vdev->vvr[i].vr_mutex);
}

static void vop_virtio_reset_devices(struct vop_info *vi)
{
	struct list_head *pos, *tmp;
	struct vop_vdev *vdev;

	list_for_each_safe(pos, tmp, &vi->vdev_list) {
		vdev = list_entry(pos, struct vop_vdev, list);
		vop_virtio_device_reset(vdev);
		vdev->poll_wake = 1;
		wake_up(&vdev->waitq);
	}
}

static void vop_bh_handler(struct work_struct *work)
{
	struct vop_vdev *vdev = container_of(work, struct vop_vdev,
			virtio_bh_work);

	if (vdev->dc->used_address_updated)
		vop_virtio_init_post(vdev);

	if (vdev->dc->vdev_reset)
		vop_virtio_device_reset(vdev);

	vdev->poll_wake = 1;
	wake_up(&vdev->waitq);
}

static irqreturn_t _vop_virtio_intr_handler(int irq, void *data)
{
	struct vop_vdev *vdev = data;
	struct vop_device *vpdev = vdev->vpdev;

	vpdev->hw_ops->ack_interrupt(vpdev, vdev->virtio_db);
	schedule_work(&vdev->virtio_bh_work);
	return IRQ_HANDLED;
}

static int vop_virtio_config_change(struct vop_vdev *vdev, void *argp)
{
	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
	int ret = 0, retry, i;
	struct vop_device *vpdev = vdev->vpdev;
	struct vop_info *vi = dev_get_drvdata(&vpdev->dev);
	struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
	s8 db = bootparam->h2c_config_db;

	mutex_lock(&vi->vop_mutex);
	for (i = 0; i < vdev->dd->num_vq; i++)
		mutex_lock_nested(&vdev->vvr[i].vr_mutex, i + 1);

	if (db == -1 || vdev->dd->type == -1) {
		ret = -EIO;
		goto exit;
	}

	memcpy(mic_vq_configspace(vdev->dd), argp, vdev->dd->config_len);
	vdev->dc->config_change = MIC_VIRTIO_PARAM_CONFIG_CHANGED;
	vpdev->hw_ops->send_intr(vpdev, db);

	for (retry = 100; retry--;) {
		ret = wait_event_timeout(wake, vdev->dc->guest_ack,
					 msecs_to_jiffies(100));
		if (ret)
			break;
	}

	dev_dbg(vop_dev(vdev),
		"%s %d retry: %d\n", __func__, __LINE__, retry);
	vdev->dc->config_change = 0;
	vdev->dc->guest_ack = 0;
exit:
	for (i = 0; i < vdev->dd->num_vq; i++)
		mutex_unlock(&vdev->vvr[i].vr_mutex);
	mutex_unlock(&vi->vop_mutex);
	return ret;
}

static int vop_copy_dp_entry(struct vop_vdev *vdev,
			     struct mic_device_desc *argp, __u8 *type,
			     struct mic_device_desc **devpage)
{
	struct vop_device *vpdev = vdev->vpdev;
	struct mic_device_desc *devp;
	struct mic_vqconfig *vqconfig;
	int ret = 0, i;
	bool slot_found = false;

	vqconfig = mic_vq_config(argp);
	for (i = 0; i < argp->num_vq; i++) {
		if (le16_to_cpu(vqconfig[i].num) > MIC_MAX_VRING_ENTRIES) {
			ret =  -EINVAL;
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, ret);
			goto exit;
		}
	}

	/* Find the first free device page entry */
	for (i = sizeof(struct mic_bootparam);
		i < MIC_DP_SIZE - mic_total_desc_size(argp);
		i += mic_total_desc_size(devp)) {
		devp = vpdev->hw_ops->get_dp(vpdev) + i;
		if (devp->type == 0 || devp->type == -1) {
			slot_found = true;
			break;
		}
	}
	if (!slot_found) {
		ret =  -EINVAL;
		dev_err(vop_dev(vdev), "%s %d err %d\n",
			__func__, __LINE__, ret);
		goto exit;
	}
	/*
	 * Save off the type before doing the memcpy. Type will be set in the
	 * end after completing all initialization for the new device.
	 */
	*type = argp->type;
	argp->type = 0;
	memcpy(devp, argp, mic_desc_size(argp));

	*devpage = devp;
exit:
	return ret;
}

static void vop_init_device_ctrl(struct vop_vdev *vdev,
				 struct mic_device_desc *devpage)
{
	struct mic_device_ctrl *dc;

	dc = (void *)devpage + mic_aligned_desc_size(devpage);

	dc->config_change = 0;
	dc->guest_ack = 0;
	dc->vdev_reset = 0;
	dc->host_ack = 0;
	dc->used_address_updated = 0;
	dc->c2h_vdev_db = -1;
	dc->h2c_vdev_db = -1;
	vdev->dc = dc;
}

static int vop_virtio_add_device(struct vop_vdev *vdev,
				 struct mic_device_desc *argp)
{
	struct vop_info *vi = vdev->vi;
	struct vop_device *vpdev = vi->vpdev;
	struct mic_device_desc *dd = NULL;
	struct mic_vqconfig *vqconfig;
	int vr_size, i, j, ret;
	u8 type = 0;
	s8 db = -1;
	char irqname[16];
	struct mic_bootparam *bootparam;
	u16 num;
	dma_addr_t vr_addr;

	bootparam = vpdev->hw_ops->get_dp(vpdev);
	init_waitqueue_head(&vdev->waitq);
	INIT_LIST_HEAD(&vdev->list);
	vdev->vpdev = vpdev;

	ret = vop_copy_dp_entry(vdev, argp, &type, &dd);
	if (ret) {
		dev_err(vop_dev(vdev), "%s %d err %d\n",
			__func__, __LINE__, ret);
		kfree(vdev);
		return ret;
	}

	vop_init_device_ctrl(vdev, dd);

	vdev->dd = dd;
	vdev->virtio_id = type;
	vqconfig = mic_vq_config(dd);
	INIT_WORK(&vdev->virtio_bh_work, vop_bh_handler);

	for (i = 0; i < dd->num_vq; i++) {
		struct vop_vringh *vvr = &vdev->vvr[i];
		struct mic_vring *vr = &vdev->vvr[i].vring;

		num = le16_to_cpu(vqconfig[i].num);
		mutex_init(&vvr->vr_mutex);
		vr_size = PAGE_ALIGN(vring_size(num, MIC_VIRTIO_RING_ALIGN) +
			sizeof(struct _mic_vring_info));
		vr->va = (void *)
			__get_free_pages(GFP_KERNEL | __GFP_ZERO,
					 get_order(vr_size));
		if (!vr->va) {
			ret = -ENOMEM;
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, ret);
			goto err;
		}
		vr->len = vr_size;
		vr->info = vr->va + vring_size(num, MIC_VIRTIO_RING_ALIGN);
		vr->info->magic = cpu_to_le32(MIC_MAGIC + vdev->virtio_id + i);
		vr_addr = dma_map_single(&vpdev->dev, vr->va, vr_size,
					 DMA_BIDIRECTIONAL);
		if (dma_mapping_error(&vpdev->dev, vr_addr)) {
			free_pages((unsigned long)vr->va, get_order(vr_size));
			ret = -ENOMEM;
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, ret);
			goto err;
		}
		vqconfig[i].address = cpu_to_le64(vr_addr);

		vring_init(&vr->vr, num, vr->va, MIC_VIRTIO_RING_ALIGN);
		ret = vringh_init_kern(&vvr->vrh,
				       *(u32 *)mic_vq_features(vdev->dd),
				       num, false, vr->vr.desc, vr->vr.avail,
				       vr->vr.used);
		if (ret) {
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, ret);
			goto err;
		}
		vringh_kiov_init(&vvr->riov, NULL, 0);
		vringh_kiov_init(&vvr->wiov, NULL, 0);
		vvr->head = USHRT_MAX;
		vvr->vdev = vdev;
		vvr->vrh.notify = _vop_notify;
		dev_dbg(&vpdev->dev,
			"%s %d index %d va %p info %p vr_size 0x%x\n",
			__func__, __LINE__, i, vr->va, vr->info, vr_size);
		vvr->buf = (void *)__get_free_pages(GFP_KERNEL,
					get_order(VOP_INT_DMA_BUF_SIZE));
		vvr->buf_da = dma_map_single(&vpdev->dev,
					  vvr->buf, VOP_INT_DMA_BUF_SIZE,
					  DMA_BIDIRECTIONAL);
	}

	snprintf(irqname, sizeof(irqname), "vop%dvirtio%d", vpdev->index,
		 vdev->virtio_id);
	vdev->virtio_db = vpdev->hw_ops->next_db(vpdev);
	vdev->virtio_cookie = vpdev->hw_ops->request_irq(vpdev,
			_vop_virtio_intr_handler, irqname, vdev,
			vdev->virtio_db);
	if (IS_ERR(vdev->virtio_cookie)) {
		ret = PTR_ERR(vdev->virtio_cookie);
		dev_dbg(&vpdev->dev, "request irq failed\n");
		goto err;
	}

	vdev->dc->c2h_vdev_db = vdev->virtio_db;

	/*
	 * Order the type update with previous stores. This write barrier
	 * is paired with the corresponding read barrier before the uncached
	 * system memory read of the type, on the card while scanning the
	 * device page.
	 */
	smp_wmb();
	dd->type = type;
	argp->type = type;

	if (bootparam) {
		db = bootparam->h2c_config_db;
		if (db != -1)
			vpdev->hw_ops->send_intr(vpdev, db);
	}
	dev_dbg(&vpdev->dev, "Added virtio id %d db %d\n", dd->type, db);
	return 0;
err:
	vqconfig = mic_vq_config(dd);
	for (j = 0; j < i; j++) {
		struct vop_vringh *vvr = &vdev->vvr[j];

		dma_unmap_single(&vpdev->dev, le64_to_cpu(vqconfig[j].address),
				 vvr->vring.len, DMA_BIDIRECTIONAL);
		free_pages((unsigned long)vvr->vring.va,
			   get_order(vvr->vring.len));
	}
	return ret;
}

static void vop_dev_remove(struct vop_info *pvi, struct mic_device_ctrl *devp,
			   struct vop_device *vpdev)
{
	struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
	s8 db;
	int ret, retry;
	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);

	devp->config_change = MIC_VIRTIO_PARAM_DEV_REMOVE;
	db = bootparam->h2c_config_db;
	if (db != -1)
		vpdev->hw_ops->send_intr(vpdev, db);
	else
		goto done;
	for (retry = 15; retry--;) {
		ret = wait_event_timeout(wake, devp->guest_ack,
					 msecs_to_jiffies(1000));
		if (ret)
			break;
	}
done:
	devp->config_change = 0;
	devp->guest_ack = 0;
}

static void vop_virtio_del_device(struct vop_vdev *vdev)
{
	struct vop_info *vi = vdev->vi;
	struct vop_device *vpdev = vdev->vpdev;
	int i;
	struct mic_vqconfig *vqconfig;
	struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);

	if (!bootparam)
		goto skip_hot_remove;
	vop_dev_remove(vi, vdev->dc, vpdev);
skip_hot_remove:
	vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
	flush_work(&vdev->virtio_bh_work);
	vqconfig = mic_vq_config(vdev->dd);
	for (i = 0; i < vdev->dd->num_vq; i++) {
		struct vop_vringh *vvr = &vdev->vvr[i];

		dma_unmap_single(&vpdev->dev,
				 vvr->buf_da, VOP_INT_DMA_BUF_SIZE,
				 DMA_BIDIRECTIONAL);
		free_pages((unsigned long)vvr->buf,
			   get_order(VOP_INT_DMA_BUF_SIZE));
		vringh_kiov_cleanup(&vvr->riov);
		vringh_kiov_cleanup(&vvr->wiov);
		dma_unmap_single(&vpdev->dev, le64_to_cpu(vqconfig[i].address),
				 vvr->vring.len, DMA_BIDIRECTIONAL);
		free_pages((unsigned long)vvr->vring.va,
			   get_order(vvr->vring.len));
	}
	/*
	 * Order the type update with previous stores. This write barrier
	 * is paired with the corresponding read barrier before the uncached
	 * system memory read of the type, on the card while scanning the
	 * device page.
	 */
	smp_wmb();
	vdev->dd->type = -1;
}

/*
 * vop_sync_dma - Wrapper for synchronous DMAs.
 *
 * @dev - The address of the pointer to the device instance used
 * for DMA registration.
 * @dst - destination DMA address.
 * @src - source DMA address.
 * @len - size of the transfer.
 *
 * Return DMA_SUCCESS on success
 */
static int vop_sync_dma(struct vop_vdev *vdev, dma_addr_t dst, dma_addr_t src,
			size_t len)
{
	int err = 0;
	struct dma_device *ddev;
	struct dma_async_tx_descriptor *tx;
	struct vop_info *vi = dev_get_drvdata(&vdev->vpdev->dev);
	struct dma_chan *vop_ch = vi->dma_ch;

	if (!vop_ch) {
		err = -EBUSY;
		goto error;
	}
	ddev = vop_ch->device;
	tx = ddev->device_prep_dma_memcpy(vop_ch, dst, src, len,
		DMA_PREP_FENCE);
	if (!tx) {
		err = -ENOMEM;
		goto error;
	} else {
		dma_cookie_t cookie;

		cookie = tx->tx_submit(tx);
		if (dma_submit_error(cookie)) {
			err = -ENOMEM;
			goto error;
		}
		dma_async_issue_pending(vop_ch);
		err = dma_sync_wait(vop_ch, cookie);
	}
error:
	if (err)
		dev_err(&vi->vpdev->dev, "%s %d err %d\n",
			__func__, __LINE__, err);
	return err;
}

#define VOP_USE_DMA true

/*
 * Initiates the copies across the PCIe bus from card memory to a user
 * space buffer. When transfers are done using DMA, source/destination
 * addresses and transfer length must follow the alignment requirements of
 * the MIC DMA engine.
 */
static int vop_virtio_copy_to_user(struct vop_vdev *vdev, void __user *ubuf,
				   size_t len, u64 daddr, size_t dlen,
				   int vr_idx)
{
	struct vop_device *vpdev = vdev->vpdev;
	void __iomem *dbuf = vpdev->hw_ops->ioremap(vpdev, daddr, len);
	struct vop_vringh *vvr = &vdev->vvr[vr_idx];
	struct vop_info *vi = dev_get_drvdata(&vpdev->dev);
	size_t dma_alignment = 1 << vi->dma_ch->device->copy_align;
	bool x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1);
	size_t dma_offset, partlen;
	int err;

	if (!VOP_USE_DMA) {
		if (copy_to_user(ubuf, (void __force *)dbuf, len)) {
			err = -EFAULT;
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, err);
			goto err;
		}
		vdev->in_bytes += len;
		err = 0;
		goto err;
	}

	dma_offset = daddr - round_down(daddr, dma_alignment);
	daddr -= dma_offset;
	len += dma_offset;
	/*
	 * X100 uses DMA addresses as seen by the card so adding
	 * the aperture base is not required for DMA. However x200
	 * requires DMA addresses to be an offset into the bar so
	 * add the aperture base for x200.
	 */
	if (x200)
		daddr += vpdev->aper->pa;
	while (len) {
		partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);
		err = vop_sync_dma(vdev, vvr->buf_da, daddr,
				   ALIGN(partlen, dma_alignment));
		if (err) {
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, err);
			goto err;
		}
		if (copy_to_user(ubuf, vvr->buf + dma_offset,
				 partlen - dma_offset)) {
			err = -EFAULT;
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, err);
			goto err;
		}
		daddr += partlen;
		ubuf += partlen;
		dbuf += partlen;
		vdev->in_bytes_dma += partlen;
		vdev->in_bytes += partlen;
		len -= partlen;
		dma_offset = 0;
	}
	err = 0;
err:
	vpdev->hw_ops->iounmap(vpdev, dbuf);
	dev_dbg(vop_dev(vdev),
		"%s: ubuf %p dbuf %p len 0x%lx vr_idx 0x%x\n",
		__func__, ubuf, dbuf, len, vr_idx);
	return err;
}

/*
 * Initiates copies across the PCIe bus from a user space buffer to card
 * memory. When transfers are done using DMA, source/destination addresses
 * and transfer length must follow the alignment requirements of the MIC
 * DMA engine.
 */
static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf,
				     size_t len, u64 daddr, size_t dlen,
				     int vr_idx)
{
	struct vop_device *vpdev = vdev->vpdev;
	void __iomem *dbuf = vpdev->hw_ops->ioremap(vpdev, daddr, len);
	struct vop_vringh *vvr = &vdev->vvr[vr_idx];
	struct vop_info *vi = dev_get_drvdata(&vdev->vpdev->dev);
	size_t dma_alignment = 1 << vi->dma_ch->device->copy_align;
	bool x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1);
	size_t partlen;
	bool dma = VOP_USE_DMA;
	int err = 0;

	if (daddr & (dma_alignment - 1)) {
		vdev->tx_dst_unaligned += len;
		dma = false;
	} else if (ALIGN(len, dma_alignment) > dlen) {
		vdev->tx_len_unaligned += len;
		dma = false;
	}

	if (!dma)
		goto memcpy;

	/*
	 * X100 uses DMA addresses as seen by the card so adding
	 * the aperture base is not required for DMA. However x200
	 * requires DMA addresses to be an offset into the bar so
	 * add the aperture base for x200.
	 */
	if (x200)
		daddr += vpdev->aper->pa;
	while (len) {
		partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);

		if (copy_from_user(vvr->buf, ubuf, partlen)) {
			err = -EFAULT;
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, err);
			goto err;
		}
		err = vop_sync_dma(vdev, daddr, vvr->buf_da,
				   ALIGN(partlen, dma_alignment));
		if (err) {
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, err);
			goto err;
		}
		daddr += partlen;
		ubuf += partlen;
		dbuf += partlen;
		vdev->out_bytes_dma += partlen;
		vdev->out_bytes += partlen;
		len -= partlen;
	}
memcpy:
	/*
	 * We are copying to IO below and should ideally use something
	 * like copy_from_user_toio(..) if it existed.
	 */
	if (copy_from_user((void __force *)dbuf, ubuf, len)) {
		err = -EFAULT;
		dev_err(vop_dev(vdev), "%s %d err %d\n",
			__func__, __LINE__, err);
		goto err;
	}
	vdev->out_bytes += len;
	err = 0;
err:
	vpdev->hw_ops->iounmap(vpdev, dbuf);
	dev_dbg(vop_dev(vdev),
		"%s: ubuf %p dbuf %p len 0x%lx vr_idx 0x%x\n",
		__func__, ubuf, dbuf, len, vr_idx);
	return err;
}

#define MIC_VRINGH_READ true

/* Determine the total number of bytes consumed in a VRINGH KIOV */
static inline u32 vop_vringh_iov_consumed(struct vringh_kiov *iov)
{
	int i;
	u32 total = iov->consumed;

	for (i = 0; i < iov->i; i++)
		total += iov->iov[i].iov_len;
	return total;
}

/*
 * Traverse the VRINGH KIOV and issue the APIs to trigger the copies.
 * This API is heavily based on the vringh_iov_xfer(..) implementation
 * in vringh.c. The reason we cannot reuse vringh_iov_pull_kern(..)
 * and vringh_iov_push_kern(..) directly is because there is no
 * way to override the VRINGH xfer(..) routines as of v3.10.
 */
static int vop_vringh_copy(struct vop_vdev *vdev, struct vringh_kiov *iov,
			   void __user *ubuf, size_t len, bool read, int vr_idx,
			   size_t *out_len)
{
	int ret = 0;
	size_t partlen, tot_len = 0;

	while (len && iov->i < iov->used) {
		struct kvec *kiov = &iov->iov[iov->i];

		partlen = min(kiov->iov_len, len);
		if (read)
			ret = vop_virtio_copy_to_user(vdev, ubuf, partlen,
						      (u64)kiov->iov_base,
						      kiov->iov_len,
						      vr_idx);
		else
			ret = vop_virtio_copy_from_user(vdev, ubuf, partlen,
							(u64)kiov->iov_base,
							kiov->iov_len,
							vr_idx);
		if (ret) {
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, ret);
			break;
		}
		len -= partlen;
		ubuf += partlen;
		tot_len += partlen;
		iov->consumed += partlen;
		kiov->iov_len -= partlen;
		kiov->iov_base += partlen;
		if (!kiov->iov_len) {
			/* Fix up old iov element then increment. */
			kiov->iov_len = iov->consumed;
			kiov->iov_base -= iov->consumed;

			iov->consumed = 0;
			iov->i++;
		}
	}
	*out_len = tot_len;
	return ret;
}

/*
 * Use the standard VRINGH infrastructure in the kernel to fetch new
 * descriptors, initiate the copies and update the used ring.
 */
static int _vop_virtio_copy(struct vop_vdev *vdev, struct mic_copy_desc *copy)
{
	int ret = 0;
	u32 iovcnt = copy->iovcnt;
	struct iovec iov;
	struct iovec __user *u_iov = copy->iov;
	void __user *ubuf = NULL;
	struct vop_vringh *vvr = &vdev->vvr[copy->vr_idx];
	struct vringh_kiov *riov = &vvr->riov;
	struct vringh_kiov *wiov = &vvr->wiov;
	struct vringh *vrh = &vvr->vrh;
	u16 *head = &vvr->head;
	struct mic_vring *vr = &vvr->vring;
	size_t len = 0, out_len;

	copy->out_len = 0;
	/* Fetch a new IOVEC if all previous elements have been processed */
	if (riov->i == riov->used && wiov->i == wiov->used) {
		ret = vringh_getdesc_kern(vrh, riov, wiov,
					  head, GFP_KERNEL);
		/* Check if there are available descriptors */
		if (ret <= 0)
			return ret;
	}
	while (iovcnt) {
		if (!len) {
			/* Copy over a new iovec from user space. */
			ret = copy_from_user(&iov, u_iov, sizeof(*u_iov));
			if (ret) {
				ret = -EINVAL;
				dev_err(vop_dev(vdev), "%s %d err %d\n",
					__func__, __LINE__, ret);
				break;
			}
			len = iov.iov_len;
			ubuf = iov.iov_base;
		}
		/* Issue all the read descriptors first */
		ret = vop_vringh_copy(vdev, riov, ubuf, len,
				      MIC_VRINGH_READ, copy->vr_idx, &out_len);
		if (ret) {
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, ret);
			break;
		}
		len -= out_len;
		ubuf += out_len;
		copy->out_len += out_len;
		/* Issue the write descriptors next */
		ret = vop_vringh_copy(vdev, wiov, ubuf, len,
				      !MIC_VRINGH_READ, copy->vr_idx, &out_len);
		if (ret) {
			dev_err(vop_dev(vdev), "%s %d err %d\n",
				__func__, __LINE__, ret);
			break;
		}
		len -= out_len;
		ubuf += out_len;
		copy->out_len += out_len;
		if (!len) {
			/* One user space iovec is now completed */
			iovcnt--;
			u_iov++;
		}
		/* Exit loop if all elements in KIOVs have been processed. */
		if (riov->i == riov->used && wiov->i == wiov->used)
			break;
	}
	/*
	 * Update the used ring if a descriptor was available and some data was
	 * copied in/out and the user asked for a used ring update.
	 */
	if (*head != USHRT_MAX && copy->out_len && copy->update_used) {
		u32 total = 0;

		/* Determine the total data consumed */
		total += vop_vringh_iov_consumed(riov);
		total += vop_vringh_iov_consumed(wiov);
		vringh_complete_kern(vrh, *head, total);
		*head = USHRT_MAX;
		if (vringh_need_notify_kern(vrh) > 0)
			vringh_notify(vrh);
		vringh_kiov_cleanup(riov);
		vringh_kiov_cleanup(wiov);
		/* Update avail idx for user space */
		vr->info->avail_idx = vrh->last_avail_idx;
	}
	return ret;
}

static inline int vop_verify_copy_args(struct vop_vdev *vdev,
				       struct mic_copy_desc *copy)
{
	if (!vdev || copy->vr_idx >= vdev->dd->num_vq)
		return -EINVAL;
	return 0;
}

/* Copy a specified number of virtio descriptors in a chain */
static int vop_virtio_copy_desc(struct vop_vdev *vdev,
				struct mic_copy_desc *copy)
{
	int err;
	struct vop_vringh *vvr;

	err = vop_verify_copy_args(vdev, copy);
	if (err)
		return err;

	vvr = &vdev->vvr[copy->vr_idx];
	mutex_lock(&vvr->vr_mutex);
	if (!vop_vdevup(vdev)) {
		err = -ENODEV;
		dev_err(vop_dev(vdev), "%s %d err %d\n",
			__func__, __LINE__, err);
		goto err;
	}
	err = _vop_virtio_copy(vdev, copy);
	if (err) {
		dev_err(vop_dev(vdev), "%s %d err %d\n",
			__func__, __LINE__, err);
	}
err:
	mutex_unlock(&vvr->vr_mutex);
	return err;
}

static int vop_open(struct inode *inode, struct file *f)
{
	struct vop_vdev *vdev;
	struct vop_info *vi = container_of(f->private_data,
		struct vop_info, miscdev);

	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
	if (!vdev)
		return -ENOMEM;
	vdev->vi = vi;
	mutex_init(&vdev->vdev_mutex);
	f->private_data = vdev;
	init_completion(&vdev->destroy);
	complete(&vdev->destroy);
	return 0;
}

static int vop_release(struct inode *inode, struct file *f)
{
	struct vop_vdev *vdev = f->private_data, *vdev_tmp;
	struct vop_info *vi = vdev->vi;
	struct list_head *pos, *tmp;
	bool found = false;

	mutex_lock(&vdev->vdev_mutex);
	if (vdev->deleted)
		goto unlock;
	mutex_lock(&vi->vop_mutex);
	list_for_each_safe(pos, tmp, &vi->vdev_list) {
		vdev_tmp = list_entry(pos, struct vop_vdev, list);
		if (vdev == vdev_tmp) {
			vop_virtio_del_device(vdev);
			list_del(pos);
			found = true;
			break;
		}
	}
	mutex_unlock(&vi->vop_mutex);
unlock:
	mutex_unlock(&vdev->vdev_mutex);
	if (!found)
		wait_for_completion(&vdev->destroy);
	f->private_data = NULL;
	kfree(vdev);
	return 0;
}

static long vop_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
{
	struct vop_vdev *vdev = f->private_data;
	struct vop_info *vi = vdev->vi;
	void __user *argp = (void __user *)arg;
	int ret;

	switch (cmd) {
	case MIC_VIRTIO_ADD_DEVICE:
	{
		struct mic_device_desc dd, *dd_config;

		if (copy_from_user(&dd, argp, sizeof(dd)))
			return -EFAULT;

		if (mic_aligned_desc_size(&dd) > MIC_MAX_DESC_BLK_SIZE ||
		    dd.num_vq > MIC_MAX_VRINGS)
			return -EINVAL;

		dd_config = kzalloc(mic_desc_size(&dd), GFP_KERNEL);
		if (!dd_config)
			return -ENOMEM;
		if (copy_from_user(dd_config, argp, mic_desc_size(&dd))) {
			ret = -EFAULT;
			goto free_ret;
		}
		mutex_lock(&vdev->vdev_mutex);
		mutex_lock(&vi->vop_mutex);
		ret = vop_virtio_add_device(vdev, dd_config);
		if (ret)
			goto unlock_ret;
		list_add_tail(&vdev->list, &vi->vdev_list);
unlock_ret:
		mutex_unlock(&vi->vop_mutex);
		mutex_unlock(&vdev->vdev_mutex);
free_ret:
		kfree(dd_config);
		return ret;
	}
	case MIC_VIRTIO_COPY_DESC:
	{
		struct mic_copy_desc copy;

		mutex_lock(&vdev->vdev_mutex);
		ret = vop_vdev_inited(vdev);
		if (ret)
			goto _unlock_ret;

		if (copy_from_user(&copy, argp, sizeof(copy))) {
			ret = -EFAULT;
			goto _unlock_ret;
		}

		ret = vop_virtio_copy_desc(vdev, &copy);
		if (ret < 0)
			goto _unlock_ret;
		if (copy_to_user(
			&((struct mic_copy_desc __user *)argp)->out_len,
			&copy.out_len, sizeof(copy.out_len)))
			ret = -EFAULT;
_unlock_ret:
		mutex_unlock(&vdev->vdev_mutex);
		return ret;
	}
	case MIC_VIRTIO_CONFIG_CHANGE:
	{
		void *buf;

		mutex_lock(&vdev->vdev_mutex);
		ret = vop_vdev_inited(vdev);
		if (ret)
			goto __unlock_ret;
		buf = kzalloc(vdev->dd->config_len, GFP_KERNEL);
		if (!buf) {
			ret = -ENOMEM;
			goto __unlock_ret;
		}
		if (copy_from_user(buf, argp, vdev->dd->config_len)) {
			ret = -EFAULT;
			goto done;
		}
		ret = vop_virtio_config_change(vdev, buf);
done:
		kfree(buf);
__unlock_ret:
		mutex_unlock(&vdev->vdev_mutex);
		return ret;
	}
	default:
		return -ENOIOCTLCMD;
	};
	return 0;
}

/*
 * We return POLLIN | POLLOUT from poll when new buffers are enqueued, and
 * not when previously enqueued buffers may be available. This means that
 * in the card->host (TX) path, when userspace is unblocked by poll it
 * must drain all available descriptors or it can stall.
 */
static unsigned int vop_poll(struct file *f, poll_table *wait)
{
	struct vop_vdev *vdev = f->private_data;
	int mask = 0;

	mutex_lock(&vdev->vdev_mutex);
	if (vop_vdev_inited(vdev)) {
		mask = POLLERR;
		goto done;
	}
	poll_wait(f, &vdev->waitq, wait);
	if (vop_vdev_inited(vdev)) {
		mask = POLLERR;
	} else if (vdev->poll_wake) {
		vdev->poll_wake = 0;
		mask = POLLIN | POLLOUT;
	}
done:
	mutex_unlock(&vdev->vdev_mutex);
	return mask;
}

static inline int
vop_query_offset(struct vop_vdev *vdev, unsigned long offset,
		 unsigned long *size, unsigned long *pa)
{
	struct vop_device *vpdev = vdev->vpdev;
	unsigned long start = MIC_DP_SIZE;
	int i;

	/*
	 * MMAP interface is as follows:
	 * offset				region
	 * 0x0					virtio device_page
	 * 0x1000				first vring
	 * 0x1000 + size of 1st vring		second vring
	 * ....
	 */
	if (!offset) {
		*pa = virt_to_phys(vpdev->hw_ops->get_dp(vpdev));
		*size = MIC_DP_SIZE;
		return 0;
	}

	for (i = 0; i < vdev->dd->num_vq; i++) {
		struct vop_vringh *vvr = &vdev->vvr[i];

		if (offset == start) {
			*pa = virt_to_phys(vvr->vring.va);
			*size = vvr->vring.len;
			return 0;
		}
		start += vvr->vring.len;
	}
	return -1;
}

/*
 * Maps the device page and virtio rings to user space for readonly access.
 */
static int vop_mmap(struct file *f, struct vm_area_struct *vma)
{
	struct vop_vdev *vdev = f->private_data;
	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
	unsigned long pa, size = vma->vm_end - vma->vm_start, size_rem = size;
	int i, err;

	err = vop_vdev_inited(vdev);
	if (err)
		goto ret;
	if (vma->vm_flags & VM_WRITE) {
		err = -EACCES;
		goto ret;
	}
	while (size_rem) {
		i = vop_query_offset(vdev, offset, &size, &pa);
		if (i < 0) {
			err = -EINVAL;
			goto ret;
		}
		err = remap_pfn_range(vma, vma->vm_start + offset,
				      pa >> PAGE_SHIFT, size,
				      vma->vm_page_prot);
		if (err)
			goto ret;
		size_rem -= size;
		offset += size;
	}
ret:
	return err;
}

static const struct file_operations vop_fops = {
	.open = vop_open,
	.release = vop_release,
	.unlocked_ioctl = vop_ioctl,
	.poll = vop_poll,
	.mmap = vop_mmap,
	.owner = THIS_MODULE,
};

int vop_host_init(struct vop_info *vi)
{
	int rc;
	struct miscdevice *mdev;
	struct vop_device *vpdev = vi->vpdev;

	INIT_LIST_HEAD(&vi->vdev_list);
	vi->dma_ch = vpdev->dma_ch;
	mdev = &vi->miscdev;
	mdev->minor = MISC_DYNAMIC_MINOR;
	snprintf(vi->name, sizeof(vi->name), "vop_virtio%d", vpdev->index);
	mdev->name = vi->name;
	mdev->fops = &vop_fops;
	mdev->parent = &vpdev->dev;

	rc = misc_register(mdev);
	if (rc)
		dev_err(&vpdev->dev, "%s failed rc %d\n", __func__, rc);
	return rc;
}

void vop_host_uninit(struct vop_info *vi)
{
	struct list_head *pos, *tmp;
	struct vop_vdev *vdev;

	mutex_lock(&vi->vop_mutex);
	vop_virtio_reset_devices(vi);
	list_for_each_safe(pos, tmp, &vi->vdev_list) {
		vdev = list_entry(pos, struct vop_vdev, list);
		list_del(pos);
		reinit_completion(&vdev->destroy);
		mutex_unlock(&vi->vop_mutex);
		mutex_lock(&vdev->vdev_mutex);
		vop_virtio_del_device(vdev);
		vdev->deleted = true;
		mutex_unlock(&vdev->vdev_mutex);
		complete(&vdev->destroy);
		mutex_lock(&vi->vop_mutex);
	}
	mutex_unlock(&vi->vop_mutex);
	misc_deregister(&vi->miscdev);
}