1 /*
2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *	- Redistributions of source code must retain the above
15  *	  copyright notice, this list of conditions and the following
16  *	  disclaimer.
17  *
18  *	- Redistributions in binary form must reproduce the above
19  *	  copyright notice, this list of conditions and the following
20  *	  disclaimer in the documentation and/or other materials
21  *	  provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 #include <linux/kernel.h>
33 #include <linux/slab.h>
34 #include <linux/mm.h>
35 #include <linux/scatterlist.h>
36 #include <linux/kfifo.h>
37 #include <scsi/scsi_cmnd.h>
38 #include <scsi/scsi_host.h>
39 
40 #include "iscsi_iser.h"
41 
42 /* Constant PDU lengths calculations */
43 #define ISER_TOTAL_HEADERS_LEN  (sizeof (struct iser_hdr) + \
44 				 sizeof (struct iscsi_hdr))
45 
46 /* iser_dto_add_regd_buff - increments the reference count for *
47  * the registered buffer & adds it to the DTO object           */
48 static void iser_dto_add_regd_buff(struct iser_dto *dto,
49 				   struct iser_regd_buf *regd_buf,
50 				   unsigned long use_offset,
51 				   unsigned long use_size)
52 {
53 	int add_idx;
54 
55 	atomic_inc(&regd_buf->ref_count);
56 
57 	add_idx = dto->regd_vector_len;
58 	dto->regd[add_idx] = regd_buf;
59 	dto->used_sz[add_idx] = use_size;
60 	dto->offset[add_idx] = use_offset;
61 
62 	dto->regd_vector_len++;
63 }
64 
65 /* Register user buffer memory and initialize passive rdma
66  *  dto descriptor. Total data size is stored in
67  *  iser_task->data[ISER_DIR_IN].data_len
68  */
69 static int iser_prepare_read_cmd(struct iscsi_task *task,
70 				 unsigned int edtl)
71 
72 {
73 	struct iscsi_iser_task *iser_task = task->dd_data;
74 	struct iser_regd_buf *regd_buf;
75 	int err;
76 	struct iser_hdr *hdr = &iser_task->desc.iser_header;
77 	struct iser_data_buf *buf_in = &iser_task->data[ISER_DIR_IN];
78 
79 	err = iser_dma_map_task_data(iser_task,
80 				     buf_in,
81 				     ISER_DIR_IN,
82 				     DMA_FROM_DEVICE);
83 	if (err)
84 		return err;
85 
86 	if (edtl > iser_task->data[ISER_DIR_IN].data_len) {
87 		iser_err("Total data length: %ld, less than EDTL: "
88 			 "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
89 			 iser_task->data[ISER_DIR_IN].data_len, edtl,
90 			 task->itt, iser_task->iser_conn);
91 		return -EINVAL;
92 	}
93 
94 	err = iser_reg_rdma_mem(iser_task,ISER_DIR_IN);
95 	if (err) {
96 		iser_err("Failed to set up Data-IN RDMA\n");
97 		return err;
98 	}
99 	regd_buf = &iser_task->rdma_regd[ISER_DIR_IN];
100 
101 	hdr->flags    |= ISER_RSV;
102 	hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
103 	hdr->read_va   = cpu_to_be64(regd_buf->reg.va);
104 
105 	iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
106 		 task->itt, regd_buf->reg.rkey,
107 		 (unsigned long long)regd_buf->reg.va);
108 
109 	return 0;
110 }
111 
112 /* Register user buffer memory and initialize passive rdma
113  *  dto descriptor. Total data size is stored in
114  *  task->data[ISER_DIR_OUT].data_len
115  */
116 static int
117 iser_prepare_write_cmd(struct iscsi_task *task,
118 		       unsigned int imm_sz,
119 		       unsigned int unsol_sz,
120 		       unsigned int edtl)
121 {
122 	struct iscsi_iser_task *iser_task = task->dd_data;
123 	struct iser_regd_buf *regd_buf;
124 	int err;
125 	struct iser_dto *send_dto = &iser_task->desc.dto;
126 	struct iser_hdr *hdr = &iser_task->desc.iser_header;
127 	struct iser_data_buf *buf_out = &iser_task->data[ISER_DIR_OUT];
128 
129 	err = iser_dma_map_task_data(iser_task,
130 				     buf_out,
131 				     ISER_DIR_OUT,
132 				     DMA_TO_DEVICE);
133 	if (err)
134 		return err;
135 
136 	if (edtl > iser_task->data[ISER_DIR_OUT].data_len) {
137 		iser_err("Total data length: %ld, less than EDTL: %d, "
138 			 "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
139 			 iser_task->data[ISER_DIR_OUT].data_len,
140 			 edtl, task->itt, task->conn);
141 		return -EINVAL;
142 	}
143 
144 	err = iser_reg_rdma_mem(iser_task,ISER_DIR_OUT);
145 	if (err != 0) {
146 		iser_err("Failed to register write cmd RDMA mem\n");
147 		return err;
148 	}
149 
150 	regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
151 
152 	if (unsol_sz < edtl) {
153 		hdr->flags     |= ISER_WSV;
154 		hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
155 		hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);
156 
157 		iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
158 			 "VA:%#llX + unsol:%d\n",
159 			 task->itt, regd_buf->reg.rkey,
160 			 (unsigned long long)regd_buf->reg.va, unsol_sz);
161 	}
162 
163 	if (imm_sz > 0) {
164 		iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
165 			 task->itt, imm_sz);
166 		iser_dto_add_regd_buff(send_dto,
167 				       regd_buf,
168 				       0,
169 				       imm_sz);
170 	}
171 
172 	return 0;
173 }
174 
175 /**
176  * iser_post_receive_control - allocates, initializes and posts receive DTO.
177  */
178 static int iser_post_receive_control(struct iscsi_conn *conn)
179 {
180 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
181 	struct iser_desc     *rx_desc;
182 	struct iser_regd_buf *regd_hdr;
183 	struct iser_regd_buf *regd_data;
184 	struct iser_dto      *recv_dto = NULL;
185 	struct iser_device  *device = iser_conn->ib_conn->device;
186 	int rx_data_size, err;
187 	int posts, outstanding_unexp_pdus;
188 
189 	/* for the login sequence we must support rx of upto 8K; login is done
190 	 * after conn create/bind (connect) and conn stop/bind (reconnect),
191 	 * what's common for both schemes is that the connection is not started
192 	 */
193 	if (conn->c_stage != ISCSI_CONN_STARTED)
194 		rx_data_size = ISCSI_DEF_MAX_RECV_SEG_LEN;
195 	else /* FIXME till user space sets conn->max_recv_dlength correctly */
196 		rx_data_size = 128;
197 
198 	outstanding_unexp_pdus =
199 		atomic_xchg(&iser_conn->ib_conn->unexpected_pdu_count, 0);
200 
201 	/*
202 	 * in addition to the response buffer, replace those consumed by
203 	 * unexpected pdus.
204 	 */
205 	for (posts = 0; posts < 1 + outstanding_unexp_pdus; posts++) {
206 		rx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
207 		if (rx_desc == NULL) {
208 			iser_err("Failed to alloc desc for post recv %d\n",
209 				 posts);
210 			err = -ENOMEM;
211 			goto post_rx_cache_alloc_failure;
212 		}
213 		rx_desc->type = ISCSI_RX;
214 		rx_desc->data = kmalloc(rx_data_size, GFP_NOIO);
215 		if (rx_desc->data == NULL) {
216 			iser_err("Failed to alloc data buf for post recv %d\n",
217 				 posts);
218 			err = -ENOMEM;
219 			goto post_rx_kmalloc_failure;
220 		}
221 
222 		recv_dto = &rx_desc->dto;
223 		recv_dto->ib_conn = iser_conn->ib_conn;
224 		recv_dto->regd_vector_len = 0;
225 
226 		regd_hdr = &rx_desc->hdr_regd_buf;
227 		memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
228 		regd_hdr->device  = device;
229 		regd_hdr->virt_addr  = rx_desc; /* == &rx_desc->iser_header */
230 		regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
231 
232 		iser_reg_single(device, regd_hdr, DMA_FROM_DEVICE);
233 
234 		iser_dto_add_regd_buff(recv_dto, regd_hdr, 0, 0);
235 
236 		regd_data = &rx_desc->data_regd_buf;
237 		memset(regd_data, 0, sizeof(struct iser_regd_buf));
238 		regd_data->device  = device;
239 		regd_data->virt_addr  = rx_desc->data;
240 		regd_data->data_size  = rx_data_size;
241 
242 		iser_reg_single(device, regd_data, DMA_FROM_DEVICE);
243 
244 		iser_dto_add_regd_buff(recv_dto, regd_data, 0, 0);
245 
246 		err = iser_post_recv(rx_desc);
247 		if (err) {
248 			iser_err("Failed iser_post_recv for post %d\n", posts);
249 			goto post_rx_post_recv_failure;
250 		}
251 	}
252 	/* all posts successful */
253 	return 0;
254 
255 post_rx_post_recv_failure:
256 	iser_dto_buffs_release(recv_dto);
257 	kfree(rx_desc->data);
258 post_rx_kmalloc_failure:
259 	kmem_cache_free(ig.desc_cache, rx_desc);
260 post_rx_cache_alloc_failure:
261 	if (posts > 0) {
262 		/*
263 		 * response buffer posted, but did not replace all unexpected
264 		 * pdu recv bufs. Ignore error, retry occurs next send
265 		 */
266 		outstanding_unexp_pdus -= (posts - 1);
267 		err = 0;
268 	}
269 	atomic_add(outstanding_unexp_pdus,
270 		   &iser_conn->ib_conn->unexpected_pdu_count);
271 
272 	return err;
273 }
274 
275 /* creates a new tx descriptor and adds header regd buffer */
276 static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
277 				  struct iser_desc       *tx_desc)
278 {
279 	struct iser_regd_buf *regd_hdr = &tx_desc->hdr_regd_buf;
280 	struct iser_dto      *send_dto = &tx_desc->dto;
281 
282 	memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
283 	regd_hdr->device  = iser_conn->ib_conn->device;
284 	regd_hdr->virt_addr  = tx_desc; /* == &tx_desc->iser_header */
285 	regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
286 
287 	send_dto->ib_conn         = iser_conn->ib_conn;
288 	send_dto->notify_enable   = 1;
289 	send_dto->regd_vector_len = 0;
290 
291 	memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
292 	tx_desc->iser_header.flags = ISER_VER;
293 
294 	iser_dto_add_regd_buff(send_dto, regd_hdr, 0, 0);
295 }
296 
297 /**
298  *  iser_conn_set_full_featured_mode - (iSER API)
299  */
300 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn)
301 {
302 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
303 
304 	int i;
305 	/*
306 	 * FIXME this value should be declared to the target during login with
307 	 * the MaxOutstandingUnexpectedPDUs key when supported
308 	 */
309 	int initial_post_recv_bufs_num = ISER_MAX_RX_MISC_PDUS;
310 
311 	iser_dbg("Initially post: %d\n", initial_post_recv_bufs_num);
312 
313 	/* Check that there is no posted recv or send buffers left - */
314 	/* they must be consumed during the login phase */
315 	BUG_ON(atomic_read(&iser_conn->ib_conn->post_recv_buf_count) != 0);
316 	BUG_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);
317 
318 	/* Initial post receive buffers */
319 	for (i = 0; i < initial_post_recv_bufs_num; i++) {
320 		if (iser_post_receive_control(conn) != 0) {
321 			iser_err("Failed to post recv bufs at:%d conn:0x%p\n",
322 				 i, conn);
323 			return -ENOMEM;
324 		}
325 	}
326 	iser_dbg("Posted %d post recv bufs, conn:0x%p\n", i, conn);
327 	return 0;
328 }
329 
330 static int
331 iser_check_xmit(struct iscsi_conn *conn, void *task)
332 {
333 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
334 
335 	if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
336 	    ISER_QP_MAX_REQ_DTOS) {
337 		iser_dbg("%ld can't xmit task %p\n",jiffies,task);
338 		return -ENOBUFS;
339 	}
340 	return 0;
341 }
342 
343 
344 /**
345  * iser_send_command - send command PDU
346  */
347 int iser_send_command(struct iscsi_conn *conn,
348 		      struct iscsi_task *task)
349 {
350 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
351 	struct iscsi_iser_task *iser_task = task->dd_data;
352 	struct iser_dto *send_dto = NULL;
353 	unsigned long edtl;
354 	int err = 0;
355 	struct iser_data_buf *data_buf;
356 	struct iscsi_cmd *hdr =  (struct iscsi_cmd *)task->hdr;
357 	struct scsi_cmnd *sc  =  task->sc;
358 
359 	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
360 		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
361 		return -EPERM;
362 	}
363 	if (iser_check_xmit(conn, task))
364 		return -ENOBUFS;
365 
366 	edtl = ntohl(hdr->data_length);
367 
368 	/* build the tx desc regd header and add it to the tx desc dto */
369 	iser_task->desc.type = ISCSI_TX_SCSI_COMMAND;
370 	send_dto = &iser_task->desc.dto;
371 	send_dto->task = iser_task;
372 	iser_create_send_desc(iser_conn, &iser_task->desc);
373 
374 	if (hdr->flags & ISCSI_FLAG_CMD_READ)
375 		data_buf = &iser_task->data[ISER_DIR_IN];
376 	else
377 		data_buf = &iser_task->data[ISER_DIR_OUT];
378 
379 	if (scsi_sg_count(sc)) { /* using a scatter list */
380 		data_buf->buf  = scsi_sglist(sc);
381 		data_buf->size = scsi_sg_count(sc);
382 	}
383 
384 	data_buf->data_len = scsi_bufflen(sc);
385 
386 	if (hdr->flags & ISCSI_FLAG_CMD_READ) {
387 		err = iser_prepare_read_cmd(task, edtl);
388 		if (err)
389 			goto send_command_error;
390 	}
391 	if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
392 		err = iser_prepare_write_cmd(task,
393 					     task->imm_count,
394 				             task->imm_count +
395 					     task->unsol_r2t.data_length,
396 					     edtl);
397 		if (err)
398 			goto send_command_error;
399 	}
400 
401 	iser_reg_single(iser_conn->ib_conn->device,
402 			send_dto->regd[0], DMA_TO_DEVICE);
403 
404 	if (iser_post_receive_control(conn) != 0) {
405 		iser_err("post_recv failed!\n");
406 		err = -ENOMEM;
407 		goto send_command_error;
408 	}
409 
410 	iser_task->status = ISER_TASK_STATUS_STARTED;
411 
412 	err = iser_post_send(&iser_task->desc);
413 	if (!err)
414 		return 0;
415 
416 send_command_error:
417 	iser_dto_buffs_release(send_dto);
418 	iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
419 	return err;
420 }
421 
422 /**
423  * iser_send_data_out - send data out PDU
424  */
425 int iser_send_data_out(struct iscsi_conn *conn,
426 		       struct iscsi_task *task,
427 		       struct iscsi_data *hdr)
428 {
429 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
430 	struct iscsi_iser_task *iser_task = task->dd_data;
431 	struct iser_desc *tx_desc = NULL;
432 	struct iser_dto *send_dto = NULL;
433 	unsigned long buf_offset;
434 	unsigned long data_seg_len;
435 	uint32_t itt;
436 	int err = 0;
437 
438 	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
439 		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
440 		return -EPERM;
441 	}
442 
443 	if (iser_check_xmit(conn, task))
444 		return -ENOBUFS;
445 
446 	itt = (__force uint32_t)hdr->itt;
447 	data_seg_len = ntoh24(hdr->dlength);
448 	buf_offset   = ntohl(hdr->offset);
449 
450 	iser_dbg("%s itt %d dseg_len %d offset %d\n",
451 		 __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
452 
453 	tx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
454 	if (tx_desc == NULL) {
455 		iser_err("Failed to alloc desc for post dataout\n");
456 		return -ENOMEM;
457 	}
458 
459 	tx_desc->type = ISCSI_TX_DATAOUT;
460 	memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
461 
462 	/* build the tx desc regd header and add it to the tx desc dto */
463 	send_dto = &tx_desc->dto;
464 	send_dto->task = iser_task;
465 	iser_create_send_desc(iser_conn, tx_desc);
466 
467 	iser_reg_single(iser_conn->ib_conn->device,
468 			send_dto->regd[0], DMA_TO_DEVICE);
469 
470 	/* all data was registered for RDMA, we can use the lkey */
471 	iser_dto_add_regd_buff(send_dto,
472 			       &iser_task->rdma_regd[ISER_DIR_OUT],
473 			       buf_offset,
474 			       data_seg_len);
475 
476 	if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
477 		iser_err("Offset:%ld & DSL:%ld in Data-Out "
478 			 "inconsistent with total len:%ld, itt:%d\n",
479 			 buf_offset, data_seg_len,
480 			 iser_task->data[ISER_DIR_OUT].data_len, itt);
481 		err = -EINVAL;
482 		goto send_data_out_error;
483 	}
484 	iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
485 		 itt, buf_offset, data_seg_len);
486 
487 
488 	err = iser_post_send(tx_desc);
489 	if (!err)
490 		return 0;
491 
492 send_data_out_error:
493 	iser_dto_buffs_release(send_dto);
494 	kmem_cache_free(ig.desc_cache, tx_desc);
495 	iser_err("conn %p failed err %d\n",conn, err);
496 	return err;
497 }
498 
499 int iser_send_control(struct iscsi_conn *conn,
500 		      struct iscsi_task *task)
501 {
502 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
503 	struct iscsi_iser_task *iser_task = task->dd_data;
504 	struct iser_desc *mdesc = &iser_task->desc;
505 	struct iser_dto *send_dto = NULL;
506 	unsigned long data_seg_len;
507 	int err = 0;
508 	struct iser_regd_buf *regd_buf;
509 	struct iser_device *device;
510 	unsigned char opcode;
511 
512 	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
513 		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
514 		return -EPERM;
515 	}
516 
517 	if (iser_check_xmit(conn, task))
518 		return -ENOBUFS;
519 
520 	/* build the tx desc regd header and add it to the tx desc dto */
521 	mdesc->type = ISCSI_TX_CONTROL;
522 	send_dto = &mdesc->dto;
523 	send_dto->task = NULL;
524 	iser_create_send_desc(iser_conn, mdesc);
525 
526 	device = iser_conn->ib_conn->device;
527 
528 	iser_reg_single(device, send_dto->regd[0], DMA_TO_DEVICE);
529 
530 	data_seg_len = ntoh24(task->hdr->dlength);
531 
532 	if (data_seg_len > 0) {
533 		regd_buf = &mdesc->data_regd_buf;
534 		memset(regd_buf, 0, sizeof(struct iser_regd_buf));
535 		regd_buf->device = device;
536 		regd_buf->virt_addr = task->data;
537 		regd_buf->data_size = task->data_count;
538 		iser_reg_single(device, regd_buf,
539 				DMA_TO_DEVICE);
540 		iser_dto_add_regd_buff(send_dto, regd_buf,
541 				       0,
542 				       data_seg_len);
543 	}
544 
545 	opcode = task->hdr->opcode & ISCSI_OPCODE_MASK;
546 
547 	/* post recv buffer for response if one is expected */
548 	if (!(opcode == ISCSI_OP_NOOP_OUT && task->hdr->itt == RESERVED_ITT)) {
549 		if (iser_post_receive_control(conn) != 0) {
550 			iser_err("post_rcv_buff failed!\n");
551 			err = -ENOMEM;
552 			goto send_control_error;
553 		}
554 	}
555 
556 	err = iser_post_send(mdesc);
557 	if (!err)
558 		return 0;
559 
560 send_control_error:
561 	iser_dto_buffs_release(send_dto);
562 	iser_err("conn %p failed err %d\n",conn, err);
563 	return err;
564 }
565 
566 /**
567  * iser_rcv_dto_completion - recv DTO completion
568  */
569 void iser_rcv_completion(struct iser_desc *rx_desc,
570 			 unsigned long dto_xfer_len)
571 {
572 	struct iser_dto *dto = &rx_desc->dto;
573 	struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
574 	struct iscsi_task *task;
575 	struct iscsi_iser_task *iser_task;
576 	struct iscsi_hdr *hdr;
577 	char   *rx_data = NULL;
578 	int     rx_data_len = 0;
579 	unsigned char opcode;
580 
581 	hdr = &rx_desc->iscsi_header;
582 
583 	iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);
584 
585 	if (dto_xfer_len > ISER_TOTAL_HEADERS_LEN) { /* we have data */
586 		rx_data_len = dto_xfer_len - ISER_TOTAL_HEADERS_LEN;
587 		rx_data     = dto->regd[1]->virt_addr;
588 		rx_data    += dto->offset[1];
589 	}
590 
591 	opcode = hdr->opcode & ISCSI_OPCODE_MASK;
592 
593 	if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
594 		spin_lock(&conn->iscsi_conn->session->lock);
595 		task = iscsi_itt_to_ctask(conn->iscsi_conn, hdr->itt);
596 		if (task)
597 			__iscsi_get_task(task);
598 		spin_unlock(&conn->iscsi_conn->session->lock);
599 
600 		if (!task)
601 			iser_err("itt can't be matched to task!!! "
602 				 "conn %p opcode %d itt %d\n",
603 				 conn->iscsi_conn, opcode, hdr->itt);
604 		else {
605 			iser_task = task->dd_data;
606 			iser_dbg("itt %d task %p\n",hdr->itt, task);
607 			iser_task->status = ISER_TASK_STATUS_COMPLETED;
608 			iser_task_rdma_finalize(iser_task);
609 			iscsi_put_task(task);
610 		}
611 	}
612 	iser_dto_buffs_release(dto);
613 
614 	iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);
615 
616 	kfree(rx_desc->data);
617 	kmem_cache_free(ig.desc_cache, rx_desc);
618 
619 	/* decrementing conn->post_recv_buf_count only --after-- freeing the   *
620 	 * task eliminates the need to worry on tasks which are completed in   *
621 	 * parallel to the execution of iser_conn_term. So the code that waits *
622 	 * for the posted rx bufs refcount to become zero handles everything   */
623 	atomic_dec(&conn->ib_conn->post_recv_buf_count);
624 
625 	/*
626 	 * if an unexpected PDU was received then the recv wr consumed must
627 	 * be replaced, this is done in the next send of a control-type PDU
628 	 */
629 	if (opcode == ISCSI_OP_NOOP_IN && hdr->itt == RESERVED_ITT) {
630 		/* nop-in with itt = 0xffffffff */
631 		atomic_inc(&conn->ib_conn->unexpected_pdu_count);
632 	}
633 	else if (opcode == ISCSI_OP_ASYNC_EVENT) {
634 		/* asyncronous message */
635 		atomic_inc(&conn->ib_conn->unexpected_pdu_count);
636 	}
637 	/* a reject PDU consumes the recv buf posted for the response */
638 }
639 
640 void iser_snd_completion(struct iser_desc *tx_desc)
641 {
642 	struct iser_dto        *dto = &tx_desc->dto;
643 	struct iser_conn       *ib_conn = dto->ib_conn;
644 	struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
645 	struct iscsi_conn      *conn = iser_conn->iscsi_conn;
646 	struct iscsi_task *task;
647 	int resume_tx = 0;
648 
649 	iser_dbg("Initiator, Data sent dto=0x%p\n", dto);
650 
651 	iser_dto_buffs_release(dto);
652 
653 	if (tx_desc->type == ISCSI_TX_DATAOUT)
654 		kmem_cache_free(ig.desc_cache, tx_desc);
655 
656 	if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
657 	    ISER_QP_MAX_REQ_DTOS)
658 		resume_tx = 1;
659 
660 	atomic_dec(&ib_conn->post_send_buf_count);
661 
662 	if (resume_tx) {
663 		iser_dbg("%ld resuming tx\n",jiffies);
664 		iscsi_conn_queue_work(conn);
665 	}
666 
667 	if (tx_desc->type == ISCSI_TX_CONTROL) {
668 		/* this arithmetic is legal by libiscsi dd_data allocation */
669 		task = (void *) ((long)(void *)tx_desc -
670 				  sizeof(struct iscsi_task));
671 		if (task->hdr->itt == RESERVED_ITT)
672 			iscsi_put_task(task);
673 	}
674 }
675 
676 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
677 
678 {
679 	iser_task->status = ISER_TASK_STATUS_INIT;
680 
681 	iser_task->dir[ISER_DIR_IN] = 0;
682 	iser_task->dir[ISER_DIR_OUT] = 0;
683 
684 	iser_task->data[ISER_DIR_IN].data_len  = 0;
685 	iser_task->data[ISER_DIR_OUT].data_len = 0;
686 
687 	memset(&iser_task->rdma_regd[ISER_DIR_IN], 0,
688 	       sizeof(struct iser_regd_buf));
689 	memset(&iser_task->rdma_regd[ISER_DIR_OUT], 0,
690 	       sizeof(struct iser_regd_buf));
691 }
692 
693 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
694 {
695 	int deferred;
696 	int is_rdma_aligned = 1;
697 	struct iser_regd_buf *regd;
698 
699 	/* if we were reading, copy back to unaligned sglist,
700 	 * anyway dma_unmap and free the copy
701 	 */
702 	if (iser_task->data_copy[ISER_DIR_IN].copy_buf != NULL) {
703 		is_rdma_aligned = 0;
704 		iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_IN);
705 	}
706 	if (iser_task->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
707 		is_rdma_aligned = 0;
708 		iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_OUT);
709 	}
710 
711 	if (iser_task->dir[ISER_DIR_IN]) {
712 		regd = &iser_task->rdma_regd[ISER_DIR_IN];
713 		deferred = iser_regd_buff_release(regd);
714 		if (deferred) {
715 			iser_err("%d references remain for BUF-IN rdma reg\n",
716 				 atomic_read(&regd->ref_count));
717 		}
718 	}
719 
720 	if (iser_task->dir[ISER_DIR_OUT]) {
721 		regd = &iser_task->rdma_regd[ISER_DIR_OUT];
722 		deferred = iser_regd_buff_release(regd);
723 		if (deferred) {
724 			iser_err("%d references remain for BUF-OUT rdma reg\n",
725 				 atomic_read(&regd->ref_count));
726 		}
727 	}
728 
729        /* if the data was unaligned, it was already unmapped and then copied */
730        if (is_rdma_aligned)
731 		iser_dma_unmap_task_data(iser_task);
732 }
733 
734 void iser_dto_buffs_release(struct iser_dto *dto)
735 {
736 	int i;
737 
738 	for (i = 0; i < dto->regd_vector_len; i++)
739 		iser_regd_buff_release(dto->regd[i]);
740 }
741 
742