aboutsummaryrefslogtreecommitdiff
path: root/drivers/infiniband/ulp/iser/iser_initiator.c
blob: 278fcbccc2d995e21b167d7623575009f2fa948c (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
/*
 * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. 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.
 *
 * $Id: iser_initiator.c 6964 2006-05-07 11:11:43Z ogerlitz $
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <asm/io.h>
#include <asm/scatterlist.h>
#include <linux/scatterlist.h>
#include <linux/kfifo.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>

#include "iscsi_iser.h"

/* Constant PDU lengths calculations */
#define ISER_TOTAL_HEADERS_LEN  (sizeof (struct iser_hdr) + \
				 sizeof (struct iscsi_hdr))

/* iser_dto_add_regd_buff - increments the reference count for *
 * the registered buffer & adds it to the DTO object           */
static void iser_dto_add_regd_buff(struct iser_dto *dto,
				   struct iser_regd_buf *regd_buf,
				   unsigned long use_offset,
				   unsigned long use_size)
{
	int add_idx;

	atomic_inc(&regd_buf->ref_count);

	add_idx = dto->regd_vector_len;
	dto->regd[add_idx] = regd_buf;
	dto->used_sz[add_idx] = use_size;
	dto->offset[add_idx] = use_offset;

	dto->regd_vector_len++;
}

/* Register user buffer memory and initialize passive rdma
 *  dto descriptor. Total data size is stored in
 *  iser_ctask->data[ISER_DIR_IN].data_len
 */
static int iser_prepare_read_cmd(struct iscsi_cmd_task *ctask,
				 unsigned int edtl)

{
	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
	struct iser_regd_buf *regd_buf;
	int err;
	struct iser_hdr *hdr = &iser_ctask->desc.iser_header;
	struct iser_data_buf *buf_in = &iser_ctask->data[ISER_DIR_IN];

	err = iser_dma_map_task_data(iser_ctask,
				     buf_in,
				     ISER_DIR_IN,
				     DMA_FROM_DEVICE);
	if (err)
		return err;

	if (edtl > iser_ctask->data[ISER_DIR_IN].data_len) {
		iser_err("Total data length: %ld, less than EDTL: "
			 "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
			 iser_ctask->data[ISER_DIR_IN].data_len, edtl,
			 ctask->itt, iser_ctask->iser_conn);
		return -EINVAL;
	}

	err = iser_reg_rdma_mem(iser_ctask,ISER_DIR_IN);
	if (err) {
		iser_err("Failed to set up Data-IN RDMA\n");
		return err;
	}
	regd_buf = &iser_ctask->rdma_regd[ISER_DIR_IN];

	hdr->flags    |= ISER_RSV;
	hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
	hdr->read_va   = cpu_to_be64(regd_buf->reg.va);

	iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
		 ctask->itt, regd_buf->reg.rkey,
		 (unsigned long long)regd_buf->reg.va);

	return 0;
}

/* Register user buffer memory and initialize passive rdma
 *  dto descriptor. Total data size is stored in
 *  ctask->data[ISER_DIR_OUT].data_len
 */
static int
iser_prepare_write_cmd(struct iscsi_cmd_task *ctask,
		       unsigned int imm_sz,
		       unsigned int unsol_sz,
		       unsigned int edtl)
{
	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
	struct iser_regd_buf *regd_buf;
	int err;
	struct iser_dto *send_dto = &iser_ctask->desc.dto;
	struct iser_hdr *hdr = &iser_ctask->desc.iser_header;
	struct iser_data_buf *buf_out = &iser_ctask->data[ISER_DIR_OUT];

	err = iser_dma_map_task_data(iser_ctask,
				     buf_out,
				     ISER_DIR_OUT,
				     DMA_TO_DEVICE);
	if (err)
		return err;

	if (edtl > iser_ctask->data[ISER_DIR_OUT].data_len) {
		iser_err("Total data length: %ld, less than EDTL: %d, "
			 "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
			 iser_ctask->data[ISER_DIR_OUT].data_len,
			 edtl, ctask->itt, ctask->conn);
		return -EINVAL;
	}

	err = iser_reg_rdma_mem(iser_ctask,ISER_DIR_OUT);
	if (err != 0) {
		iser_err("Failed to register write cmd RDMA mem\n");
		return err;
	}

	regd_buf = &iser_ctask->rdma_regd[ISER_DIR_OUT];

	if (unsol_sz < edtl) {
		hdr->flags     |= ISER_WSV;
		hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
		hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);

		iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
			 "VA:%#llX + unsol:%d\n",
			 ctask->itt, regd_buf->reg.rkey,
			 (unsigned long long)regd_buf->reg.va, unsol_sz);
	}

	if (imm_sz > 0) {
		iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
			 ctask->itt, imm_sz);
		iser_dto_add_regd_buff(send_dto,
				       regd_buf,
				       0,
				       imm_sz);
	}

	return 0;
}

/**
 * iser_post_receive_control - allocates, initializes and posts receive DTO.
 */
static int iser_post_receive_control(struct iscsi_conn *conn)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iser_desc     *rx_desc;
	struct iser_regd_buf *regd_hdr;
	struct iser_regd_buf *regd_data;
	struct iser_dto      *recv_dto = NULL;
	struct iser_device  *device = iser_conn->ib_conn->device;
	int rx_data_size, err = 0;

	rx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
	if (rx_desc == NULL) {
		iser_err("Failed to alloc desc for post recv\n");
		return -ENOMEM;
	}
	rx_desc->type = ISCSI_RX;

	/* for the login sequence we must support rx of upto 8K; login is done
	 * after conn create/bind (connect) and conn stop/bind (reconnect),
	 * what's common for both schemes is that the connection is not started
	 */
	if (conn->c_stage != ISCSI_CONN_STARTED)
		rx_data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
	else /* FIXME till user space sets conn->max_recv_dlength correctly */
		rx_data_size = 128;

	rx_desc->data = kmalloc(rx_data_size, GFP_NOIO);
	if (rx_desc->data == NULL) {
		iser_err("Failed to alloc data buf for post recv\n");
		err = -ENOMEM;
		goto post_rx_kmalloc_failure;
	}

	recv_dto = &rx_desc->dto;
	recv_dto->ib_conn = iser_conn->ib_conn;
	recv_dto->regd_vector_len = 0;

	regd_hdr = &rx_desc->hdr_regd_buf;
	memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
	regd_hdr->device  = device;
	regd_hdr->virt_addr  = rx_desc; /* == &rx_desc->iser_header */
	regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;

	iser_reg_single(device, regd_hdr, DMA_FROM_DEVICE);

	iser_dto_add_regd_buff(recv_dto, regd_hdr, 0, 0);

	regd_data = &rx_desc->data_regd_buf;
	memset(regd_data, 0, sizeof(struct iser_regd_buf));
	regd_data->device  = device;
	regd_data->virt_addr  = rx_desc->data;
	regd_data->data_size  = rx_data_size;

	iser_reg_single(device, regd_data, DMA_FROM_DEVICE);

	iser_dto_add_regd_buff(recv_dto, regd_data, 0, 0);

	err = iser_post_recv(rx_desc);
	if (!err)
		return 0;

	/* iser_post_recv failed */
	iser_dto_buffs_release(recv_dto);
	kfree(rx_desc->data);
post_rx_kmalloc_failure:
	kmem_cache_free(ig.desc_cache, rx_desc);
	return err;
}

/* creates a new tx descriptor and adds header regd buffer */
static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
				  struct iser_desc       *tx_desc)
{
	struct iser_regd_buf *regd_hdr = &tx_desc->hdr_regd_buf;
	struct iser_dto      *send_dto = &tx_desc->dto;

	memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
	regd_hdr->device  = iser_conn->ib_conn->device;
	regd_hdr->virt_addr  = tx_desc; /* == &tx_desc->iser_header */
	regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;

	send_dto->ib_conn         = iser_conn->ib_conn;
	send_dto->notify_enable   = 1;
	send_dto->regd_vector_len = 0;

	memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
	tx_desc->iser_header.flags = ISER_VER;

	iser_dto_add_regd_buff(send_dto, regd_hdr, 0, 0);
}

/**
 *  iser_conn_set_full_featured_mode - (iSER API)
 */
int iser_conn_set_full_featured_mode(struct iscsi_conn *conn)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;

	int i;
	/* no need to keep it in a var, we are after login so if this should
	 * be negotiated, by now the result should be available here */
	int initial_post_recv_bufs_num = ISER_MAX_RX_MISC_PDUS;

	iser_dbg("Initially post: %d\n", initial_post_recv_bufs_num);

	/* Check that there is no posted recv or send buffers left - */
	/* they must be consumed during the login phase */
	BUG_ON(atomic_read(&iser_conn->ib_conn->post_recv_buf_count) != 0);
	BUG_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);

	/* Initial post receive buffers */
	for (i = 0; i < initial_post_recv_bufs_num; i++) {
		if (iser_post_receive_control(conn) != 0) {
			iser_err("Failed to post recv bufs at:%d conn:0x%p\n",
				 i, conn);
			return -ENOMEM;
		}
	}
	iser_dbg("Posted %d post recv bufs, conn:0x%p\n", i, conn);
	return 0;
}

static int
iser_check_xmit(struct iscsi_conn *conn, void *task)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;

	if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
	    ISER_QP_MAX_REQ_DTOS) {
		iser_dbg("%ld can't xmit task %p\n",jiffies,task);
		return -ENOBUFS;
	}
	return 0;
}


/**
 * iser_send_command - send command PDU
 */
int iser_send_command(struct iscsi_conn     *conn,
		      struct iscsi_cmd_task *ctask)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
	struct iser_dto *send_dto = NULL;
	unsigned long edtl;
	int err = 0;
	struct iser_data_buf *data_buf;

	struct iscsi_cmd *hdr =  ctask->hdr;
	struct scsi_cmnd *sc  =  ctask->sc;

	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
		return -EPERM;
	}
	if (iser_check_xmit(conn, ctask))
		return -ENOBUFS;

	edtl = ntohl(hdr->data_length);

	/* build the tx desc regd header and add it to the tx desc dto */
	iser_ctask->desc.type = ISCSI_TX_SCSI_COMMAND;
	send_dto = &iser_ctask->desc.dto;
	send_dto->ctask = iser_ctask;
	iser_create_send_desc(iser_conn, &iser_ctask->desc);

	if (hdr->flags & ISCSI_FLAG_CMD_READ)
		data_buf = &iser_ctask->data[ISER_DIR_IN];
	else
		data_buf = &iser_ctask->data[ISER_DIR_OUT];

	if (sc->use_sg) { /* using a scatter list */
		data_buf->buf  = sc->request_buffer;
		data_buf->size = sc->use_sg;
	} else if (sc->request_bufflen) {
		/* using a single buffer - convert it into one entry SG */
		sg_init_one(&data_buf->sg_single,
			    sc->request_buffer, sc->request_bufflen);
		data_buf->buf   = &data_buf->sg_single;
		data_buf->size  = 1;
	}

	data_buf->data_len = sc->request_bufflen;

	if (hdr->flags & ISCSI_FLAG_CMD_READ) {
		err = iser_prepare_read_cmd(ctask, edtl);
		if (err)
			goto send_command_error;
	}
	if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
		err = iser_prepare_write_cmd(ctask,
					     ctask->imm_count,
				             ctask->imm_count +
					     ctask->unsol_count,
					     edtl);
		if (err)
			goto send_command_error;
	}

	iser_reg_single(iser_conn->ib_conn->device,
			send_dto->regd[0], DMA_TO_DEVICE);

	if (iser_post_receive_control(conn) != 0) {
		iser_err("post_recv failed!\n");
		err = -ENOMEM;
		goto send_command_error;
	}

	iser_ctask->status = ISER_TASK_STATUS_STARTED;

	err = iser_post_send(&iser_ctask->desc);
	if (!err)
		return 0;

send_command_error:
	iser_dto_buffs_release(send_dto);
	iser_err("conn %p failed ctask->itt %d err %d\n",conn, ctask->itt, err);
	return err;
}

/**
 * iser_send_data_out - send data out PDU
 */
int iser_send_data_out(struct iscsi_conn     *conn,
		       struct iscsi_cmd_task *ctask,
		       struct iscsi_data *hdr)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
	struct iser_desc *tx_desc = NULL;
	struct iser_dto *send_dto = NULL;
	unsigned long buf_offset;
	unsigned long data_seg_len;
	unsigned int itt;
	int err = 0;

	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
		return -EPERM;
	}

	if (iser_check_xmit(conn, ctask))
		return -ENOBUFS;

	itt = ntohl(hdr->itt);
	data_seg_len = ntoh24(hdr->dlength);
	buf_offset   = ntohl(hdr->offset);

	iser_dbg("%s itt %d dseg_len %d offset %d\n",
		 __func__,(int)itt,(int)data_seg_len,(int)buf_offset);

	tx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
	if (tx_desc == NULL) {
		iser_err("Failed to alloc desc for post dataout\n");
		return -ENOMEM;
	}

	tx_desc->type = ISCSI_TX_DATAOUT;
	memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));

	/* build the tx desc regd header and add it to the tx desc dto */
	send_dto = &tx_desc->dto;
	send_dto->ctask = iser_ctask;
	iser_create_send_desc(iser_conn, tx_desc);

	iser_reg_single(iser_conn->ib_conn->device,
			send_dto->regd[0], DMA_TO_DEVICE);

	/* all data was registered for RDMA, we can use the lkey */
	iser_dto_add_regd_buff(send_dto,
			       &iser_ctask->rdma_regd[ISER_DIR_OUT],
			       buf_offset,
			       data_seg_len);

	if (buf_offset + data_seg_len > iser_ctask->data[ISER_DIR_OUT].data_len) {
		iser_err("Offset:%ld & DSL:%ld in Data-Out "
			 "inconsistent with total len:%ld, itt:%d\n",
			 buf_offset, data_seg_len,
			 iser_ctask->data[ISER_DIR_OUT].data_len, itt);
		err = -EINVAL;
		goto send_data_out_error;
	}
	iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
		 itt, buf_offset, data_seg_len);


	err = iser_post_send(tx_desc);
	if (!err)
		return 0;

send_data_out_error:
	iser_dto_buffs_release(send_dto);
	kmem_cache_free(ig.desc_cache, tx_desc);
	iser_err("conn %p failed err %d\n",conn, err);
	return err;
}

int iser_send_control(struct iscsi_conn *conn,
		      struct iscsi_mgmt_task *mtask)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iser_desc *mdesc = mtask->dd_data;
	struct iser_dto *send_dto = NULL;
	unsigned long data_seg_len;
	int err = 0;
	struct iser_regd_buf *regd_buf;
	struct iser_device *device;

	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
		return -EPERM;
	}

	if (iser_check_xmit(conn,mtask))
		return -ENOBUFS;

	/* build the tx desc regd header and add it to the tx desc dto */
	mdesc->type = ISCSI_TX_CONTROL;
	send_dto = &mdesc->dto;
	send_dto->ctask = NULL;
	iser_create_send_desc(iser_conn, mdesc);

	device = iser_conn->ib_conn->device;

	iser_reg_single(device, send_dto->regd[0], DMA_TO_DEVICE);

	data_seg_len = ntoh24(mtask->hdr->dlength);

	if (data_seg_len > 0) {
		regd_buf = &mdesc->data_regd_buf;
		memset(regd_buf, 0, sizeof(struct iser_regd_buf));
		regd_buf->device = device;
		regd_buf->virt_addr = mtask->data;
		regd_buf->data_size = mtask->data_count;
		iser_reg_single(device, regd_buf,
				DMA_TO_DEVICE);
		iser_dto_add_regd_buff(send_dto, regd_buf,
				       0,
				       data_seg_len);
	}

	if (iser_post_receive_control(conn) != 0) {
		iser_err("post_rcv_buff failed!\n");
		err = -ENOMEM;
		goto send_control_error;
	}

	err = iser_post_send(mdesc);
	if (!err)
		return 0;

send_control_error:
	iser_dto_buffs_release(send_dto);
	iser_err("conn %p failed err %d\n",conn, err);
	return err;
}

/**
 * iser_rcv_dto_completion - recv DTO completion
 */
void iser_rcv_completion(struct iser_desc *rx_desc,
			 unsigned long dto_xfer_len)
{
	struct iser_dto        *dto = &rx_desc->dto;
	struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
	struct iscsi_session *session = conn->iscsi_conn->session;
	struct iscsi_cmd_task *ctask;
	struct iscsi_iser_cmd_task *iser_ctask;
	struct iscsi_hdr *hdr;
	char   *rx_data = NULL;
	int     rx_data_len = 0;
	unsigned int itt;
	unsigned char opcode;

	hdr = &rx_desc->iscsi_header;

	iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);

	if (dto_xfer_len > ISER_TOTAL_HEADERS_LEN) { /* we have data */
		rx_data_len = dto_xfer_len - ISER_TOTAL_HEADERS_LEN;
		rx_data     = dto->regd[1]->virt_addr;
		rx_data    += dto->offset[1];
	}

	opcode = hdr->opcode & ISCSI_OPCODE_MASK;

	if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
	        itt = get_itt(hdr->itt); /* mask out cid and age bits */
		if (!(itt < session->cmds_max))
			iser_err("itt can't be matched to task!!!"
				 "conn %p opcode %d cmds_max %d itt %d\n",
				 conn->iscsi_conn,opcode,session->cmds_max,itt);
		/* use the mapping given with the cmds array indexed by itt */
		ctask = (struct iscsi_cmd_task *)session->cmds[itt];
		iser_ctask = ctask->dd_data;
		iser_dbg("itt %d ctask %p\n",itt,ctask);
		iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
		iser_ctask_rdma_finalize(iser_ctask);
	}

	iser_dto_buffs_release(dto);

	iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);

	kfree(rx_desc->data);
	kmem_cache_free(ig.desc_cache, rx_desc);

	/* decrementing conn->post_recv_buf_count only --after-- freeing the   *
	 * task eliminates the need to worry on tasks which are completed in   *
	 * parallel to the execution of iser_conn_term. So the code that waits *
	 * for the posted rx bufs refcount to become zero handles everything   */
	atomic_dec(&conn->ib_conn->post_recv_buf_count);
}

void iser_snd_completion(struct iser_desc *tx_desc)
{
	struct iser_dto        *dto = &tx_desc->dto;
	struct iser_conn       *ib_conn = dto->ib_conn;
	struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
	struct iscsi_conn      *conn = iser_conn->iscsi_conn;
	struct iscsi_mgmt_task *mtask;
	int resume_tx = 0;

	iser_dbg("Initiator, Data sent dto=0x%p\n", dto);

	iser_dto_buffs_release(dto);

	if (tx_desc->type == ISCSI_TX_DATAOUT)
		kmem_cache_free(ig.desc_cache, tx_desc);

	if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
	    ISER_QP_MAX_REQ_DTOS)
		resume_tx = 1;

	atomic_dec(&ib_conn->post_send_buf_count);

	if (resume_tx) {
		iser_dbg("%ld resuming tx\n",jiffies);
		scsi_queue_work(conn->session->host, &conn->xmitwork);
	}

	if (tx_desc->type == ISCSI_TX_CONTROL) {
		/* this arithmetic is legal by libiscsi dd_data allocation */
		mtask = (void *) ((long)(void *)tx_desc -
				  sizeof(struct iscsi_mgmt_task));
		if (mtask->hdr->itt == RESERVED_ITT) {
			struct iscsi_session *session = conn->session;

			spin_lock(&conn->session->lock);
			list_del(&mtask->running);
			__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
				    sizeof(void*));
			spin_unlock(&session->lock);
		}
	}
}

void iser_ctask_rdma_init(struct iscsi_iser_cmd_task *iser_ctask)

{
	iser_ctask->status = ISER_TASK_STATUS_INIT;

	iser_ctask->dir[ISER_DIR_IN] = 0;
	iser_ctask->dir[ISER_DIR_OUT] = 0;

	iser_ctask->data[ISER_DIR_IN].data_len  = 0;
	iser_ctask->data[ISER_DIR_OUT].data_len = 0;

	memset(&iser_ctask->rdma_regd[ISER_DIR_IN], 0,
	       sizeof(struct iser_regd_buf));
	memset(&iser_ctask->rdma_regd[ISER_DIR_OUT], 0,
	       sizeof(struct iser_regd_buf));
}

void iser_ctask_rdma_finalize(struct iscsi_iser_cmd_task *iser_ctask)
{
	int deferred;
	int is_rdma_aligned = 1;
	struct iser_regd_buf *regd;

	/* if we were reading, copy back to unaligned sglist,
	 * anyway dma_unmap and free the copy
	 */
	if (iser_ctask->data_copy[ISER_DIR_IN].copy_buf != NULL) {
		is_rdma_aligned = 0;
		iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_IN);
	}
	if (iser_ctask->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
		is_rdma_aligned = 0;
		iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_OUT);
	}

	if (iser_ctask->dir[ISER_DIR_IN]) {
		regd = &iser_ctask->rdma_regd[ISER_DIR_IN];
		deferred = iser_regd_buff_release(regd);
		if (deferred) {
			iser_err("%d references remain for BUF-IN rdma reg\n",
				 atomic_read(&regd->ref_count));
		}
	}

	if (iser_ctask->dir[ISER_DIR_OUT]) {
		regd = &iser_ctask->rdma_regd[ISER_DIR_OUT];
		deferred = iser_regd_buff_release(regd);
		if (deferred) {
			iser_err("%d references remain for BUF-OUT rdma reg\n",
				 atomic_read(&regd->ref_count));
		}
	}

       /* if the data was unaligned, it was already unmapped and then copied */
       if (is_rdma_aligned)
		iser_dma_unmap_task_data(iser_ctask);
}

void iser_dto_buffs_release(struct iser_dto *dto)
{
	int i;

	for (i = 0; i < dto->regd_vector_len; i++)
		iser_regd_buff_release(dto->regd[i]);
}