summaryrefslogtreecommitdiffstats
path: root/drivers/net/mlx4/en_rx.c
blob: 6232227f56c33a8cfd66e59d3ffafe7589b74791 (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
/*
 * Copyright (c) 2007 Mellanox Technologies. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     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
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

#include <linux/mlx4/cq.h>
#include <linux/mlx4/qp.h>
#include <linux/skbuff.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/vmalloc.h>

#include "mlx4_en.h"

static void *get_wqe(struct mlx4_en_rx_ring *ring, int n)
{
	int offset = n << ring->srq.wqe_shift;
	return ring->buf + offset;
}

static void mlx4_en_srq_event(struct mlx4_srq *srq, enum mlx4_event type)
{
	return;
}

static int mlx4_en_get_frag_header(struct skb_frag_struct *frags, void **mac_hdr,
				   void **ip_hdr, void **tcpudp_hdr,
				   u64 *hdr_flags, void *priv)
{
	*mac_hdr = page_address(frags->page) + frags->page_offset;
	*ip_hdr = *mac_hdr + ETH_HLEN;
	*tcpudp_hdr = (struct tcphdr *)(*ip_hdr + sizeof(struct iphdr));
	*hdr_flags = LRO_IPV4 | LRO_TCP;

	return 0;
}

static int mlx4_en_alloc_frag(struct mlx4_en_priv *priv,
			      struct mlx4_en_rx_desc *rx_desc,
			      struct skb_frag_struct *skb_frags,
			      struct mlx4_en_rx_alloc *ring_alloc,
			      int i)
{
	struct mlx4_en_dev *mdev = priv->mdev;
	struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
	struct mlx4_en_rx_alloc *page_alloc = &ring_alloc[i];
	struct page *page;
	dma_addr_t dma;

	if (page_alloc->offset == frag_info->last_offset) {
		/* Allocate new page */
		page = alloc_pages(GFP_ATOMIC | __GFP_COMP, MLX4_EN_ALLOC_ORDER);
		if (!page)
			return -ENOMEM;

		skb_frags[i].page = page_alloc->page;
		skb_frags[i].page_offset = page_alloc->offset;
		page_alloc->page = page;
		page_alloc->offset = frag_info->frag_align;
	} else {
		page = page_alloc->page;
		get_page(page);

		skb_frags[i].page = page;
		skb_frags[i].page_offset = page_alloc->offset;
		page_alloc->offset += frag_info->frag_stride;
	}
	dma = pci_map_single(mdev->pdev, page_address(skb_frags[i].page) +
			     skb_frags[i].page_offset, frag_info->frag_size,
			     PCI_DMA_FROMDEVICE);
	rx_desc->data[i].addr = cpu_to_be64(dma);
	return 0;
}

static int mlx4_en_init_allocator(struct mlx4_en_priv *priv,
				  struct mlx4_en_rx_ring *ring)
{
	struct mlx4_en_rx_alloc *page_alloc;
	int i;

	for (i = 0; i < priv->num_frags; i++) {
		page_alloc = &ring->page_alloc[i];
		page_alloc->page = alloc_pages(GFP_ATOMIC | __GFP_COMP,
					       MLX4_EN_ALLOC_ORDER);
		if (!page_alloc->page)
			goto out;

		page_alloc->offset = priv->frag_info[i].frag_align;
		mlx4_dbg(DRV, priv, "Initialized allocator:%d with page:%p\n",
			 i, page_alloc->page);
	}
	return 0;

out:
	while (i--) {
		page_alloc = &ring->page_alloc[i];
		put_page(page_alloc->page);
		page_alloc->page = NULL;
	}
	return -ENOMEM;
}

static void mlx4_en_destroy_allocator(struct mlx4_en_priv *priv,
				      struct mlx4_en_rx_ring *ring)
{
	struct mlx4_en_rx_alloc *page_alloc;
	int i;

	for (i = 0; i < priv->num_frags; i++) {
		page_alloc = &ring->page_alloc[i];
		mlx4_dbg(DRV, priv, "Freeing allocator:%d count:%d\n",
			 i, page_count(page_alloc->page));

		put_page(page_alloc->page);
		page_alloc->page = NULL;
	}
}


static void mlx4_en_init_rx_desc(struct mlx4_en_priv *priv,
				 struct mlx4_en_rx_ring *ring, int index)
{
	struct mlx4_en_rx_desc *rx_desc = ring->buf + ring->stride * index;
	struct skb_frag_struct *skb_frags = ring->rx_info +
					    (index << priv->log_rx_info);
	int possible_frags;
	int i;

	/* Pre-link descriptor */
	rx_desc->next.next_wqe_index = cpu_to_be16((index + 1) & ring->size_mask);

	/* Set size and memtype fields */
	for (i = 0; i < priv->num_frags; i++) {
		skb_frags[i].size = priv->frag_info[i].frag_size;
		rx_desc->data[i].byte_count =
			cpu_to_be32(priv->frag_info[i].frag_size);
		rx_desc->data[i].lkey = cpu_to_be32(priv->mdev->mr.key);
	}

	/* If the number of used fragments does not fill up the ring stride,
	 * remaining (unused) fragments must be padded with null address/size
	 * and a special memory key */
	possible_frags = (ring->stride - sizeof(struct mlx4_en_rx_desc)) / DS_SIZE;
	for (i = priv->num_frags; i < possible_frags; i++) {
		rx_desc->data[i].byte_count = 0;
		rx_desc->data[i].lkey = cpu_to_be32(MLX4_EN_MEMTYPE_PAD);
		rx_desc->data[i].addr = 0;
	}
}


static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv,
				   struct mlx4_en_rx_ring *ring, int index)
{
	struct mlx4_en_rx_desc *rx_desc = ring->buf + (index * ring->stride);
	struct skb_frag_struct *skb_frags = ring->rx_info +
					    (index << priv->log_rx_info);
	int i;

	for (i = 0; i < priv->num_frags; i++)
		if (mlx4_en_alloc_frag(priv, rx_desc, skb_frags, ring->page_alloc, i))
			goto err;

	return 0;

err:
	while (i--)
		put_page(skb_frags[i].page);
	return -ENOMEM;
}

static inline void mlx4_en_update_rx_prod_db(struct mlx4_en_rx_ring *ring)
{
	*ring->wqres.db.db = cpu_to_be32(ring->prod & 0xffff);
}

static int mlx4_en_fill_rx_buffers(struct mlx4_en_priv *priv)
{
	struct mlx4_en_dev *mdev = priv->mdev;
	struct mlx4_en_rx_ring *ring;
	int ring_ind;
	int buf_ind;

	for (buf_ind = 0; buf_ind < priv->prof->rx_ring_size; buf_ind++) {
		for (ring_ind = 0; ring_ind < priv->rx_ring_num; ring_ind++) {
			ring = &priv->rx_ring[ring_ind];

			if (mlx4_en_prepare_rx_desc(priv, ring,
						    ring->actual_size)) {
				if (ring->actual_size < MLX4_EN_MIN_RX_SIZE) {
					mlx4_err(mdev, "Failed to allocate "
						       "enough rx buffers\n");
					return -ENOMEM;
				} else {
					if (netif_msg_rx_err(priv))
						mlx4_warn(mdev,
							  "Only %d buffers allocated\n",
							  ring->actual_size);
					goto out;
				}
			}
			ring->actual_size++;
			ring->prod++;
		}
	}
out:
	return 0;
}

static int mlx4_en_fill_rx_buf(struct net_device *dev,
			       struct mlx4_en_rx_ring *ring)
{
	struct mlx4_en_priv *priv = netdev_priv(dev);
	int num = 0;
	int err;

	while ((u32) (ring->prod - ring->cons) < ring->actual_size) {
		err = mlx4_en_prepare_rx_desc(priv, ring, ring->prod &
					      ring->size_mask);
		if (err) {
			if (netif_msg_rx_err(priv))
				mlx4_warn(priv->mdev,
					  "Failed preparing rx descriptor\n");
			priv->port_stats.rx_alloc_failed++;
			break;
		}
		++num;
		++ring->prod;
	}
	if ((u32) (ring->prod - ring->cons) == ring->size)
		ring->full = 1;

	return num;
}

static void mlx4_en_free_rx_buf(struct mlx4_en_priv *priv,
				struct mlx4_en_rx_ring *ring)
{
	struct mlx4_en_dev *mdev = priv->mdev;
	struct skb_frag_struct *skb_frags;
	struct mlx4_en_rx_desc *rx_desc;
	dma_addr_t dma;
	int index;
	int nr;

	mlx4_dbg(DRV, priv, "Freeing Rx buf - cons:%d prod:%d\n",
			ring->cons, ring->prod);

	/* Unmap and free Rx buffers */
	BUG_ON((u32) (ring->prod - ring->cons) > ring->size);
	while (ring->cons != ring->prod) {
		index = ring->cons & ring->size_mask;
		rx_desc = ring->buf + (index << ring->log_stride);
		skb_frags = ring->rx_info + (index << priv->log_rx_info);
		mlx4_dbg(DRV, priv, "Processing descriptor:%d\n", index);

		for (nr = 0; nr < priv->num_frags; nr++) {
			mlx4_dbg(DRV, priv, "Freeing fragment:%d\n", nr);
			dma = be64_to_cpu(rx_desc->data[nr].addr);

			mlx4_dbg(DRV, priv, "Unmaping buffer at dma:0x%llx\n", (u64) dma);
			pci_unmap_single(mdev->pdev, dma, skb_frags[nr].size,
					 PCI_DMA_FROMDEVICE);
			put_page(skb_frags[nr].page);
		}
		++ring->cons;
	}
}


void mlx4_en_rx_refill(struct work_struct *work)
{
	struct delayed_work *delay = container_of(work, struct delayed_work, work);
	struct mlx4_en_priv *priv = container_of(delay, struct mlx4_en_priv,
						 refill_task);
	struct mlx4_en_dev *mdev = priv->mdev;
	struct net_device *dev = priv->dev;
	struct mlx4_en_rx_ring *ring;
	int need_refill = 0;
	int i;

	mutex_lock(&mdev->state_lock);
	if (!mdev->device_up || !priv->port_up)
		goto out;

	/* We only get here if there are no receive buffers, so we can't race
	 * with Rx interrupts while filling buffers */
	for (i = 0; i < priv->rx_ring_num; i++) {
		ring = &priv->rx_ring[i];
		if (ring->need_refill) {
			if (mlx4_en_fill_rx_buf(dev, ring)) {
				ring->need_refill = 0;
				mlx4_en_update_rx_prod_db(ring);
			} else
				need_refill = 1;
		}
	}
	if (need_refill)
		queue_delayed_work(mdev->workqueue, &priv->refill_task, HZ);

out:
	mutex_unlock(&mdev->state_lock);
}


int mlx4_en_create_rx_ring(struct mlx4_en_priv *priv,
			   struct mlx4_en_rx_ring *ring, u32 size, u16 stride)
{
	struct mlx4_en_dev *mdev = priv->mdev;
	int err;
	int tmp;

	/* Sanity check SRQ size before proceeding */
	if (size >= mdev->dev->caps.max_srq_wqes)
		return -EINVAL;

	ring->prod = 0;
	ring->cons = 0;
	ring->size = size;
	ring->size_mask = size - 1;
	ring->stride = stride;
	ring->log_stride = ffs(ring->stride) - 1;
	ring->buf_size = ring->size * ring->stride;

	tmp = size * roundup_pow_of_two(MLX4_EN_MAX_RX_FRAGS *
					sizeof(struct skb_frag_struct));
	ring->rx_info = vmalloc(tmp);
	if (!ring->rx_info) {
		mlx4_err(mdev, "Failed allocating rx_info ring\n");
		return -ENOMEM;
	}
	mlx4_dbg(DRV, priv, "Allocated rx_info ring at addr:%p size:%d\n",
		 ring->rx_info, tmp);

	err = mlx4_alloc_hwq_res(mdev->dev, &ring->wqres,
				 ring->buf_size, 2 * PAGE_SIZE);
	if (err)
		goto err_ring;

	err = mlx4_en_map_buffer(&ring->wqres.buf);
	if (err) {
		mlx4_err(mdev, "Failed to map RX buffer\n");
		goto err_hwq;
	}
	ring->buf = ring->wqres.buf.direct.buf;

	/* Configure lro mngr */
	memset(&ring->lro, 0, sizeof(struct net_lro_mgr));
	ring->lro.dev = priv->dev;
	ring->lro.features = LRO_F_NAPI;
	ring->lro.frag_align_pad = NET_IP_ALIGN;
	ring->lro.ip_summed = CHECKSUM_UNNECESSARY;
	ring->lro.ip_summed_aggr = CHECKSUM_UNNECESSARY;
	ring->lro.max_desc = mdev->profile.num_lro;
	ring->lro.max_aggr = MAX_SKB_FRAGS;
	ring->lro.lro_arr = kzalloc(mdev->profile.num_lro *
				    sizeof(struct net_lro_desc),
				    GFP_KERNEL);
	if (!ring->lro.lro_arr) {
		mlx4_err(mdev, "Failed to allocate lro array\n");
		goto err_map;
	}
	ring->lro.get_frag_header = mlx4_en_get_frag_header;

	return 0;

err_map:
	mlx4_en_unmap_buffer(&ring->wqres.buf);
err_hwq:
	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
err_ring:
	vfree(ring->rx_info);
	ring->rx_info = NULL;
	return err;
}

int mlx4_en_activate_rx_rings(struct mlx4_en_priv *priv)
{
	struct mlx4_en_dev *mdev = priv->mdev;
	struct mlx4_wqe_srq_next_seg *next;
	struct mlx4_en_rx_ring *ring;
	int i;
	int ring_ind;
	int err;
	int stride = roundup_pow_of_two(sizeof(struct mlx4_en_rx_desc) +
					DS_SIZE * priv->num_frags);
	int max_gs = (stride - sizeof(struct mlx4_wqe_srq_next_seg)) / DS_SIZE;

	for (ring_ind = 0; ring_ind < priv->rx_ring_num; ring_ind++) {
		ring = &priv->rx_ring[ring_ind];

		ring->prod = 0;
		ring->cons = 0;
		ring->actual_size = 0;
		ring->cqn = priv->rx_cq[ring_ind].mcq.cqn;

		ring->stride = stride;
		ring->log_stride = ffs(ring->stride) - 1;
		ring->buf_size = ring->size * ring->stride;

		memset(ring->buf, 0, ring->buf_size);
		mlx4_en_update_rx_prod_db(ring);

		/* Initailize all descriptors */
		for (i = 0; i < ring->size; i++)
			mlx4_en_init_rx_desc(priv, ring, i);

		/* Initialize page allocators */
		err = mlx4_en_init_allocator(priv, ring);
		if (err) {
			 mlx4_err(mdev, "Failed initializing ring allocator\n");
			 goto err_allocator;
		}

		/* Fill Rx buffers */
		ring->full = 0;
	}
	if (mlx4_en_fill_rx_buffers(priv))
		goto err_buffers;

	for (ring_ind = 0; ring_ind < priv->rx_ring_num; ring_ind++) {
		ring = &priv->rx_ring[ring_ind];

		mlx4_en_update_rx_prod_db(ring);

		/* Configure SRQ representing the ring */
		ring->srq.max    = ring->size;
		ring->srq.max_gs = max_gs;
		ring->srq.wqe_shift = ilog2(ring->stride);

		for (i = 0; i < ring->srq.max; ++i) {
			next = get_wqe(ring, i);
			next->next_wqe_index =
			cpu_to_be16((i + 1) & (ring->srq.max - 1));
		}

		err = mlx4_srq_alloc(mdev->dev, mdev->priv_pdn, &ring->wqres.mtt,
				     ring->wqres.db.dma, &ring->srq);
		if (err){
			mlx4_err(mdev, "Failed to allocate srq\n");
			goto err_srq;
		}
		ring->srq.event = mlx4_en_srq_event;
	}

	return 0;

err_srq:
	while (ring_ind >= 0) {
		ring = &priv->rx_ring[ring_ind];
		mlx4_srq_free(mdev->dev, &ring->srq);
		ring_ind--;
	}

err_buffers:
	for (ring_ind = 0; ring_ind < priv->rx_ring_num; ring_ind++)
		mlx4_en_free_rx_buf(priv, &priv->rx_ring[ring_ind]);

	ring_ind = priv->rx_ring_num - 1;
err_allocator:
	while (ring_ind >= 0) {
		mlx4_en_destroy_allocator(priv, &priv->rx_ring[ring_ind]);
		ring_ind--;
	}
	return err;
}

void mlx4_en_destroy_rx_ring(struct mlx4_en_priv *priv,
			     struct mlx4_en_rx_ring *ring)
{
	struct mlx4_en_dev *mdev = priv->mdev;

	kfree(ring->lro.lro_arr);
	mlx4_en_unmap_buffer(&ring->wqres.buf);
	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
	vfree(ring->rx_info);
	ring->rx_info = NULL;
}

void mlx4_en_deactivate_rx_ring(struct mlx4_en_priv *priv,
				struct mlx4_en_rx_ring *ring)
{
	struct mlx4_en_dev *mdev = priv->mdev;

	mlx4_srq_free(mdev->dev, &ring->srq);
	mlx4_en_free_rx_buf(priv, ring);
	mlx4_en_destroy_allocator(priv, ring);
}


/* Unmap a completed descriptor and free unused pages */
static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
				    struct mlx4_en_rx_desc *rx_desc,
				    struct skb_frag_struct *skb_frags,
				    struct skb_frag_struct *skb_frags_rx,
				    struct mlx4_en_rx_alloc *page_alloc,
				    int length)
{
	struct mlx4_en_dev *mdev = priv->mdev;
	struct mlx4_en_frag_info *frag_info;
	int nr;
	dma_addr_t dma;

	/* Collect used fragments while replacing them in the HW descirptors */
	for (nr = 0; nr < priv->num_frags; nr++) {
		frag_info = &priv->frag_info[nr];
		if (length <= frag_info->frag_prefix_size)
			break;

		/* Save page reference in skb */
		skb_frags_rx[nr].page = skb_frags[nr].page;
		skb_frags_rx[nr].size = skb_frags[nr].size;
		skb_frags_rx[nr].page_offset = skb_frags[nr].page_offset;
		dma = be64_to_cpu(rx_desc->data[nr].addr);

		/* Allocate a replacement page */
		if (mlx4_en_alloc_frag(priv, rx_desc, skb_frags, page_alloc, nr))
			goto fail;

		/* Unmap buffer */
		pci_unmap_single(mdev->pdev, dma, skb_frags[nr].size,
				 PCI_DMA_FROMDEVICE);
	}
	/* Adjust size of last fragment to match actual length */
	skb_frags_rx[nr - 1].size = length -
		priv->frag_info[nr - 1].frag_prefix_size;
	return nr;

fail:
	/* Drop all accumulated fragments (which have already been replaced in
	 * the descriptor) of this packet; remaining fragments are reused... */
	while (nr > 0) {
		nr--;
		put_page(skb_frags_rx[nr].page);
	}
	return 0;
}


static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
				      struct mlx4_en_rx_desc *rx_desc,
				      struct skb_frag_struct *skb_frags,
				      struct mlx4_en_rx_alloc *page_alloc,
				      unsigned int length)
{
	struct mlx4_en_dev *mdev = priv->mdev;
	struct sk_buff *skb;
	void *va;
	int used_frags;
	dma_addr_t dma;

	skb = dev_alloc_skb(SMALL_PACKET_SIZE + NET_IP_ALIGN);
	if (!skb) {
		mlx4_dbg(RX_ERR, priv, "Failed allocating skb\n");
		return NULL;
	}
	skb->dev = priv->dev;
	skb_reserve(skb, NET_IP_ALIGN);
	skb->len = length;
	skb->truesize = length + sizeof(struct sk_buff);

	/* Get pointer to first fragment so we could copy the headers into the
	 * (linear part of the) skb */
	va = page_address(skb_frags[0].page) + skb_frags[0].page_offset;

	if (length <= SMALL_PACKET_SIZE) {
		/* We are copying all relevant data to the skb - temporarily
		 * synch buffers for the copy */
		dma = be64_to_cpu(rx_desc->data[0].addr);
		dma_sync_single_range_for_cpu(&mdev->pdev->dev, dma, 0,
					      length, DMA_FROM_DEVICE);
		skb_copy_to_linear_data(skb, va, length);
		dma_sync_single_range_for_device(&mdev->pdev->dev, dma, 0,
						 length, DMA_FROM_DEVICE);
		skb->tail += length;
	} else {

		/* Move relevant fragments to skb */
		used_frags = mlx4_en_complete_rx_desc(priv, rx_desc, skb_frags,
						      skb_shinfo(skb)->frags,
						      page_alloc, length);
		skb_shinfo(skb)->nr_frags = used_frags;

		/* Copy headers into the skb linear buffer */
		memcpy(skb->data, va, HEADER_COPY_SIZE);
		skb->tail += HEADER_COPY_SIZE;

		/* Skip headers in first fragment */
		skb_shinfo(skb)->frags[0].page_offset += HEADER_COPY_SIZE;

		/* Adjust size of first fragment */
		skb_shinfo(skb)->frags[0].size -= HEADER_COPY_SIZE;
		skb->data_len = length - HEADER_COPY_SIZE;
	}
	return skb;
}

static void mlx4_en_copy_desc(struct mlx4_en_priv *priv,
			      struct mlx4_en_rx_ring *ring,
			      int from, int to, int num)
{
	struct skb_frag_struct *skb_frags_from;
	struct skb_frag_struct *skb_frags_to;
	struct mlx4_en_rx_desc *rx_desc_from;
	struct mlx4_en_rx_desc *rx_desc_to;
	int from_index, to_index;
	int nr, i;

	for (i = 0; i < num; i++) {
		from_index = (from + i) & ring->size_mask;
		to_index = (to + i) & ring->size_mask;
		skb_frags_from = ring->rx_info + (from_index << priv->log_rx_info);
		skb_frags_to = ring->rx_info + (to_index << priv->log_rx_info);
		rx_desc_from = ring->buf + (from_index << ring->log_stride);
		rx_desc_to = ring->buf + (to_index << ring->log_stride);

		for (nr = 0; nr < priv->num_frags; nr++) {
			skb_frags_to[nr].page = skb_frags_from[nr].page;
			skb_frags_to[nr].page_offset = skb_frags_from[nr].page_offset;
			rx_desc_to->data[nr].addr = rx_desc_from->data[nr].addr;
		}
	}
}


int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int budget)
{
	struct mlx4_en_priv *priv = netdev_priv(dev);
	struct mlx4_en_dev *mdev = priv->mdev;
	struct mlx4_cqe *cqe;
	struct mlx4_en_rx_ring *ring = &priv->rx_ring[cq->ring];
	struct skb_frag_struct *skb_frags;
	struct skb_frag_struct lro_frags[MLX4_EN_MAX_RX_FRAGS];
	struct mlx4_en_rx_desc *rx_desc;
	struct sk_buff *skb;
	int index;
	int nr;
	unsigned int length;
	int polled = 0;
	int ip_summed;

	if (!priv->port_up)
		return 0;

	/* We assume a 1:1 mapping between CQEs and Rx descriptors, so Rx
	 * descriptor offset can be deduced from the CQE index instead of
	 * reading 'cqe->index' */
	index = cq->mcq.cons_index & ring->size_mask;
	cqe = &cq->buf[index];

	/* Process all completed CQEs */
	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
		    cq->mcq.cons_index & cq->size)) {

		skb_frags = ring->rx_info + (index << priv->log_rx_info);
		rx_desc = ring->buf + (index << ring->log_stride);

		/*
		 * make sure we read the CQE after we read the ownership bit
		 */
		rmb();

		/* Drop packet on bad receive or bad checksum */
		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
						MLX4_CQE_OPCODE_ERROR)) {
			mlx4_err(mdev, "CQE completed in error - vendor "
				  "syndrom:%d syndrom:%d\n",
				  ((struct mlx4_err_cqe *) cqe)->vendor_err_syndrome,
				  ((struct mlx4_err_cqe *) cqe)->syndrome);
			goto next;
		}
		if (unlikely(cqe->badfcs_enc & MLX4_CQE_BAD_FCS)) {
			mlx4_dbg(RX_ERR, priv, "Accepted frame with bad FCS\n");
			goto next;
		}

		/*
		 * Packet is OK - process it.
		 */
		length = be32_to_cpu(cqe->byte_cnt);
		ring->bytes += length;
		ring->packets++;

		if (likely(priv->rx_csum)) {
			if ((cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPOK)) &&
			    (cqe->checksum == cpu_to_be16(0xffff))) {
				priv->port_stats.rx_chksum_good++;
				/* This packet is eligible for LRO if it is:
				 * - DIX Ethernet (type interpretation)
				 * - TCP/IP (v4)
				 * - without IP options
				 * - not an IP fragment */
				if (mlx4_en_can_lro(cqe->status) &&
				    dev->features & NETIF_F_LRO) {

					nr = mlx4_en_complete_rx_desc(
						priv, rx_desc,
						skb_frags, lro_frags,
						ring->page_alloc, length);
					if (!nr)
						goto next;

					if (priv->vlgrp && (cqe->vlan_my_qpn &
							    cpu_to_be32(MLX4_CQE_VLAN_PRESENT_MASK))) {
						lro_vlan_hwaccel_receive_frags(
						       &ring->lro, lro_frags,
						       length, length,
						       priv->vlgrp,
						       be16_to_cpu(cqe->sl_vid),
						       NULL, 0);
					} else
						lro_receive_frags(&ring->lro,
								  lro_frags,
								  length,
								  length,
								  NULL, 0);

					goto next;
				}

				/* LRO not possible, complete processing here */
				ip_summed = CHECKSUM_UNNECESSARY;
				INC_PERF_COUNTER(priv->pstats.lro_misses);
			} else {
				ip_summed = CHECKSUM_NONE;
				priv->port_stats.rx_chksum_none++;
			}
		} else {
			ip_summed = CHECKSUM_NONE;
			priv->port_stats.rx_chksum_none++;
		}

		skb = mlx4_en_rx_skb(priv, rx_desc, skb_frags,
				     ring->page_alloc, length);
		if (!skb) {
			priv->stats.rx_dropped++;
			goto next;
		}

		skb->ip_summed = ip_summed;
		skb->protocol = eth_type_trans(skb, dev);

		/* Push it up the stack */
		if (priv->vlgrp && (be32_to_cpu(cqe->vlan_my_qpn) &
				    MLX4_CQE_VLAN_PRESENT_MASK)) {
			vlan_hwaccel_receive_skb(skb, priv->vlgrp,
						be16_to_cpu(cqe->sl_vid));
		} else
			netif_receive_skb(skb);

		dev->last_rx = jiffies;

next:
		++cq->mcq.cons_index;
		index = (cq->mcq.cons_index) & ring->size_mask;
		cqe = &cq->buf[index];
		if (++polled == budget) {
			/* We are here because we reached the NAPI budget -
			 * flush only pending LRO sessions */
			lro_flush_all(&ring->lro);
			goto out;
		}
	}

	/* If CQ is empty flush all LRO sessions unconditionally */
	lro_flush_all(&ring->lro);

out:
	AVG_PERF_COUNTER(priv->pstats.rx_coal_avg, polled);
	mlx4_cq_set_ci(&cq->mcq);
	wmb(); /* ensure HW sees CQ consumer before we post new buffers */
	ring->cons = cq->mcq.cons_index;
	ring->prod += polled; /* Polled descriptors were realocated in place */
	if (unlikely(!ring->full)) {
		mlx4_en_copy_desc(priv, ring, ring->cons - polled,
				  ring->prod - polled, polled);
		mlx4_en_fill_rx_buf(dev, ring);
	}
	mlx4_en_update_rx_prod_db(ring);
	return polled;
}


void mlx4_en_rx_irq(struct mlx4_cq *mcq)
{
	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
	struct mlx4_en_priv *priv = netdev_priv(cq->dev);

	if (priv->port_up)
		netif_rx_schedule(cq->dev, &cq->napi);
	else
		mlx4_en_arm_cq(priv, cq);
}

/* Rx CQ polling - called by NAPI */
int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
{
	struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
	struct net_device *dev = cq->dev;
	struct mlx4_en_priv *priv = netdev_priv(dev);
	int done;

	done = mlx4_en_process_rx_cq(dev, cq, budget);

	/* If we used up all the quota - we're probably not done yet... */
	if (done == budget)
		INC_PERF_COUNTER(priv->pstats.napi_quota);
	else {
		/* Done for now */
		netif_rx_complete(dev, napi);
		mlx4_en_arm_cq(priv, cq);
	}
	return done;
}


/* Calculate the last offset position that accomodates a full fragment
 * (assuming fagment size = stride-align) */
static int mlx4_en_last_alloc_offset(struct mlx4_en_priv *priv, u16 stride, u16 align)
{
	u16 res = MLX4_EN_ALLOC_SIZE % stride;
	u16 offset = MLX4_EN_ALLOC_SIZE - stride - res + align;

	mlx4_dbg(DRV, priv, "Calculated last offset for stride:%d align:%d "
			    "res:%d offset:%d\n", stride, align, res, offset);
	return offset;
}


static int frag_sizes[] = {
	FRAG_SZ0,
	FRAG_SZ1,
	FRAG_SZ2,
	FRAG_SZ3
};

void mlx4_en_calc_rx_buf(struct net_device *dev)
{
	struct mlx4_en_priv *priv = netdev_priv(dev);
	int eff_mtu = dev->mtu + ETH_HLEN + VLAN_HLEN + ETH_LLC_SNAP_SIZE;
	int buf_size = 0;
	int i = 0;

	while (buf_size < eff_mtu) {
		priv->frag_info[i].frag_size =
			(eff_mtu > buf_size + frag_sizes[i]) ?
				frag_sizes[i] : eff_mtu - buf_size;
		priv->frag_info[i].frag_prefix_size = buf_size;
		if (!i)	{
			priv->frag_info[i].frag_align = NET_IP_ALIGN;
			priv->frag_info[i].frag_stride =
				ALIGN(frag_sizes[i] + NET_IP_ALIGN, SMP_CACHE_BYTES);
		} else {
			priv->frag_info[i].frag_align = 0;
			priv->frag_info[i].frag_stride =
				ALIGN(frag_sizes[i], SMP_CACHE_BYTES);
		}
		priv->frag_info[i].last_offset = mlx4_en_last_alloc_offset(
						priv, priv->frag_info[i].frag_stride,
						priv->frag_info[i].frag_align);
		buf_size += priv->frag_info[i].frag_size;
		i++;
	}

	priv->num_frags = i;
	priv->rx_skb_size = eff_mtu;
	priv->log_rx_info = ROUNDUP_LOG2(i * sizeof(struct skb_frag_struct));

	mlx4_dbg(DRV, priv, "Rx buffer scatter-list (effective-mtu:%d "
		  "num_frags:%d):\n", eff_mtu, priv->num_frags);
	for (i = 0; i < priv->num_frags; i++) {
		mlx4_dbg(DRV, priv, "  frag:%d - size:%d prefix:%d align:%d "
				"stride:%d last_offset:%d\n", i,
				priv->frag_info[i].frag_size,
				priv->frag_info[i].frag_prefix_size,
				priv->frag_info[i].frag_align,
				priv->frag_info[i].frag_stride,
				priv->frag_info[i].last_offset);
	}
}

/* RSS related functions */

/* Calculate rss size and map each entry in rss table to rx ring */
void mlx4_en_set_default_rss_map(struct mlx4_en_priv *priv,
				 struct mlx4_en_rss_map *rss_map,
				 int num_entries, int num_rings)
{
	int i;

	rss_map->size = roundup_pow_of_two(num_entries);
	mlx4_dbg(DRV, priv, "Setting default RSS map of %d entires\n",
		 rss_map->size);

	for (i = 0; i < rss_map->size; i++) {
		rss_map->map[i] = i % num_rings;
		mlx4_dbg(DRV, priv, "Entry %d ---> ring %d\n", i, rss_map->map[i]);
	}
}

static void mlx4_en_sqp_event(struct mlx4_qp *qp, enum mlx4_event event)
{
    return;
}


static int mlx4_en_config_rss_qp(struct mlx4_en_priv *priv,
				 int qpn, int srqn, int cqn,
				 enum mlx4_qp_state *state,
				 struct mlx4_qp *qp)
{
	struct mlx4_en_dev *mdev = priv->mdev;
	struct mlx4_qp_context *context;
	int err = 0;

	context = kmalloc(sizeof *context , GFP_KERNEL);
	if (!context) {
		mlx4_err(mdev, "Failed to allocate qp context\n");
		return -ENOMEM;
	}

	err = mlx4_qp_alloc(mdev->dev, qpn, qp);
	if (err) {
		mlx4_err(mdev, "Failed to allocate qp #%d\n", qpn);
		goto out;
		return err;
	}
	qp->event = mlx4_en_sqp_event;

	memset(context, 0, sizeof *context);
	mlx4_en_fill_qp_context(priv, 0, 0, 0, 0, qpn, cqn, srqn, context);

	err = mlx4_qp_to_ready(mdev->dev, &priv->res.mtt, context, qp, state);
	if (err) {
		mlx4_qp_remove(mdev->dev, qp);
		mlx4_qp_free(mdev->dev, qp);
	}
out:
	kfree(context);
	return err;
}

/* Allocate rx qp's and configure them according to rss map */
int mlx4_en_config_rss_steer(struct mlx4_en_priv *priv)
{
	struct mlx4_en_dev *mdev = priv->mdev;
	struct mlx4_en_rss_map *rss_map = &priv->rss_map;
	struct mlx4_qp_context context;
	struct mlx4_en_rss_context *rss_context;
	void *ptr;
	int rss_xor = mdev->profile.rss_xor;
	u8 rss_mask = mdev->profile.rss_mask;
	int i, srqn, qpn, cqn;
	int err = 0;
	int good_qps = 0;

	mlx4_dbg(DRV, priv, "Configuring rss steering for port %u\n", priv->port);
	err = mlx4_qp_reserve_range(mdev->dev, rss_map->size,
				    rss_map->size, &rss_map->base_qpn);
	if (err) {
		mlx4_err(mdev, "Failed reserving %d qps for port %u\n",
			 rss_map->size, priv->port);
		return err;
	}

	for (i = 0; i < rss_map->size; i++) {
		cqn = priv->rx_ring[rss_map->map[i]].cqn;
		srqn = priv->rx_ring[rss_map->map[i]].srq.srqn;
		qpn = rss_map->base_qpn + i;
		err = mlx4_en_config_rss_qp(priv, qpn, srqn, cqn,
					    &rss_map->state[i],
					    &rss_map->qps[i]);
		if (err)
			goto rss_err;

		++good_qps;
	}

	/* Configure RSS indirection qp */
	err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &priv->base_qpn);
	if (err) {
		mlx4_err(mdev, "Failed to reserve range for RSS "
			       "indirection qp\n");
		goto rss_err;
	}
	err = mlx4_qp_alloc(mdev->dev, priv->base_qpn, &rss_map->indir_qp);
	if (err) {
		mlx4_err(mdev, "Failed to allocate RSS indirection QP\n");
		goto reserve_err;
	}
	rss_map->indir_qp.event = mlx4_en_sqp_event;
	mlx4_en_fill_qp_context(priv, 0, 0, 0, 1, priv->base_qpn,
				priv->rx_ring[0].cqn, 0, &context);

	ptr = ((void *) &context) + 0x3c;
	rss_context = (struct mlx4_en_rss_context *) ptr;
	rss_context->base_qpn = cpu_to_be32(ilog2(rss_map->size) << 24 |
					    (rss_map->base_qpn));
	rss_context->default_qpn = cpu_to_be32(rss_map->base_qpn);
	rss_context->hash_fn = rss_xor & 0x3;
	rss_context->flags = rss_mask << 2;

	err = mlx4_qp_to_ready(mdev->dev, &priv->res.mtt, &context,
			       &rss_map->indir_qp, &rss_map->indir_state);
	if (err)
		goto indir_err;

	return 0;

indir_err:
	mlx4_qp_modify(mdev->dev, NULL, rss_map->indir_state,
		       MLX4_QP_STATE_RST, NULL, 0, 0, &rss_map->indir_qp);
	mlx4_qp_remove(mdev->dev, &rss_map->indir_qp);
	mlx4_qp_free(mdev->dev, &rss_map->indir_qp);
reserve_err:
	mlx4_qp_release_range(mdev->dev, priv->base_qpn, 1);
rss_err:
	for (i = 0; i < good_qps; i++) {
		mlx4_qp_modify(mdev->dev, NULL, rss_map->state[i],
			       MLX4_QP_STATE_RST, NULL, 0, 0, &rss_map->qps[i]);
		mlx4_qp_remove(mdev->dev, &rss_map->qps[i]);
		mlx4_qp_free(mdev->dev, &rss_map->qps[i]);
	}
	mlx4_qp_release_range(mdev->dev, rss_map->base_qpn, rss_map->size);
	return err;
}

void mlx4_en_release_rss_steer(struct mlx4_en_priv *priv)
{
	struct mlx4_en_dev *mdev = priv->mdev;
	struct mlx4_en_rss_map *rss_map = &priv->rss_map;
	int i;

	mlx4_qp_modify(mdev->dev, NULL, rss_map->indir_state,
		       MLX4_QP_STATE_RST, NULL, 0, 0, &rss_map->indir_qp);
	mlx4_qp_remove(mdev->dev, &rss_map->indir_qp);
	mlx4_qp_free(mdev->dev, &rss_map->indir_qp);
	mlx4_qp_release_range(mdev->dev, priv->base_qpn, 1);

	for (i = 0; i < rss_map->size; i++) {
		mlx4_qp_modify(mdev->dev, NULL, rss_map->state[i],
			       MLX4_QP_STATE_RST, NULL, 0, 0, &rss_map->qps[i]);
		mlx4_qp_remove(mdev->dev, &rss_map->qps[i]);
		mlx4_qp_free(mdev->dev, &rss_map->qps[i]);
	}
	mlx4_qp_release_range(mdev->dev, rss_map->base_qpn, rss_map->size);
}