1 /*******************************************************************************
2  * This file contains iSCSI extentions for RDMA (iSER) Verbs
3  *
4  * (c) Copyright 2013 Datera, Inc.
5  *
6  * Nicholas A. Bellinger <nab@linux-iscsi.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  ****************************************************************************/
18 
19 #include <linux/string.h>
20 #include <linux/module.h>
21 #include <linux/scatterlist.h>
22 #include <linux/socket.h>
23 #include <linux/in.h>
24 #include <linux/in6.h>
25 #include <rdma/ib_verbs.h>
26 #include <rdma/rdma_cm.h>
27 #include <target/target_core_base.h>
28 #include <target/target_core_fabric.h>
29 #include <target/iscsi/iscsi_transport.h>
30 #include <linux/semaphore.h>
31 
32 #include "ib_isert.h"
33 
34 #define	ISERT_MAX_CONN		8
35 #define ISER_MAX_RX_CQ_LEN	(ISERT_QP_MAX_RECV_DTOS * ISERT_MAX_CONN)
36 #define ISER_MAX_TX_CQ_LEN \
37 	((ISERT_QP_MAX_REQ_DTOS + ISCSI_DEF_XMIT_CMDS_MAX) * ISERT_MAX_CONN)
38 #define ISER_MAX_CQ_LEN		(ISER_MAX_RX_CQ_LEN + ISER_MAX_TX_CQ_LEN + \
39 				 ISERT_MAX_CONN)
40 
41 static int isert_debug_level;
42 module_param_named(debug_level, isert_debug_level, int, 0644);
43 MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:0)");
44 
45 static DEFINE_MUTEX(device_list_mutex);
46 static LIST_HEAD(device_list);
47 static struct workqueue_struct *isert_comp_wq;
48 static struct workqueue_struct *isert_release_wq;
49 
50 static int
51 isert_put_response(struct iscsi_conn *conn, struct iscsi_cmd *cmd);
52 static int
53 isert_login_post_recv(struct isert_conn *isert_conn);
54 static int
55 isert_rdma_accept(struct isert_conn *isert_conn);
56 struct rdma_cm_id *isert_setup_id(struct isert_np *isert_np);
57 
58 static void isert_release_work(struct work_struct *work);
59 static void isert_recv_done(struct ib_cq *cq, struct ib_wc *wc);
60 static void isert_send_done(struct ib_cq *cq, struct ib_wc *wc);
61 static void isert_login_recv_done(struct ib_cq *cq, struct ib_wc *wc);
62 static void isert_login_send_done(struct ib_cq *cq, struct ib_wc *wc);
63 
64 static inline bool
65 isert_prot_cmd(struct isert_conn *conn, struct se_cmd *cmd)
66 {
67 	return (conn->pi_support &&
68 		cmd->prot_op != TARGET_PROT_NORMAL);
69 }
70 
71 
72 static void
73 isert_qp_event_callback(struct ib_event *e, void *context)
74 {
75 	struct isert_conn *isert_conn = context;
76 
77 	isert_err("%s (%d): conn %p\n",
78 		  ib_event_msg(e->event), e->event, isert_conn);
79 
80 	switch (e->event) {
81 	case IB_EVENT_COMM_EST:
82 		rdma_notify(isert_conn->cm_id, IB_EVENT_COMM_EST);
83 		break;
84 	case IB_EVENT_QP_LAST_WQE_REACHED:
85 		isert_warn("Reached TX IB_EVENT_QP_LAST_WQE_REACHED\n");
86 		break;
87 	default:
88 		break;
89 	}
90 }
91 
92 static struct isert_comp *
93 isert_comp_get(struct isert_conn *isert_conn)
94 {
95 	struct isert_device *device = isert_conn->device;
96 	struct isert_comp *comp;
97 	int i, min = 0;
98 
99 	mutex_lock(&device_list_mutex);
100 	for (i = 0; i < device->comps_used; i++)
101 		if (device->comps[i].active_qps <
102 		    device->comps[min].active_qps)
103 			min = i;
104 	comp = &device->comps[min];
105 	comp->active_qps++;
106 	mutex_unlock(&device_list_mutex);
107 
108 	isert_info("conn %p, using comp %p min_index: %d\n",
109 		   isert_conn, comp, min);
110 
111 	return comp;
112 }
113 
114 static void
115 isert_comp_put(struct isert_comp *comp)
116 {
117 	mutex_lock(&device_list_mutex);
118 	comp->active_qps--;
119 	mutex_unlock(&device_list_mutex);
120 }
121 
122 static struct ib_qp *
123 isert_create_qp(struct isert_conn *isert_conn,
124 		struct isert_comp *comp,
125 		struct rdma_cm_id *cma_id)
126 {
127 	struct isert_device *device = isert_conn->device;
128 	struct ib_qp_init_attr attr;
129 	int ret;
130 
131 	memset(&attr, 0, sizeof(struct ib_qp_init_attr));
132 	attr.event_handler = isert_qp_event_callback;
133 	attr.qp_context = isert_conn;
134 	attr.send_cq = comp->cq;
135 	attr.recv_cq = comp->cq;
136 	attr.cap.max_send_wr = ISERT_QP_MAX_REQ_DTOS + 1;
137 	attr.cap.max_recv_wr = ISERT_QP_MAX_RECV_DTOS + 1;
138 	attr.cap.max_rdma_ctxs = ISCSI_DEF_XMIT_CMDS_MAX;
139 	attr.cap.max_send_sge = device->ib_device->attrs.max_sge;
140 	attr.cap.max_recv_sge = 1;
141 	attr.sq_sig_type = IB_SIGNAL_REQ_WR;
142 	attr.qp_type = IB_QPT_RC;
143 	if (device->pi_capable)
144 		attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
145 
146 	ret = rdma_create_qp(cma_id, device->pd, &attr);
147 	if (ret) {
148 		isert_err("rdma_create_qp failed for cma_id %d\n", ret);
149 		return ERR_PTR(ret);
150 	}
151 
152 	return cma_id->qp;
153 }
154 
155 static int
156 isert_conn_setup_qp(struct isert_conn *isert_conn, struct rdma_cm_id *cma_id)
157 {
158 	struct isert_comp *comp;
159 	int ret;
160 
161 	comp = isert_comp_get(isert_conn);
162 	isert_conn->qp = isert_create_qp(isert_conn, comp, cma_id);
163 	if (IS_ERR(isert_conn->qp)) {
164 		ret = PTR_ERR(isert_conn->qp);
165 		goto err;
166 	}
167 
168 	return 0;
169 err:
170 	isert_comp_put(comp);
171 	return ret;
172 }
173 
174 static int
175 isert_alloc_rx_descriptors(struct isert_conn *isert_conn)
176 {
177 	struct isert_device *device = isert_conn->device;
178 	struct ib_device *ib_dev = device->ib_device;
179 	struct iser_rx_desc *rx_desc;
180 	struct ib_sge *rx_sg;
181 	u64 dma_addr;
182 	int i, j;
183 
184 	isert_conn->rx_descs = kzalloc(ISERT_QP_MAX_RECV_DTOS *
185 				sizeof(struct iser_rx_desc), GFP_KERNEL);
186 	if (!isert_conn->rx_descs)
187 		return -ENOMEM;
188 
189 	rx_desc = isert_conn->rx_descs;
190 
191 	for (i = 0; i < ISERT_QP_MAX_RECV_DTOS; i++, rx_desc++)  {
192 		dma_addr = ib_dma_map_single(ib_dev, (void *)rx_desc,
193 					ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
194 		if (ib_dma_mapping_error(ib_dev, dma_addr))
195 			goto dma_map_fail;
196 
197 		rx_desc->dma_addr = dma_addr;
198 
199 		rx_sg = &rx_desc->rx_sg;
200 		rx_sg->addr = rx_desc->dma_addr;
201 		rx_sg->length = ISER_RX_PAYLOAD_SIZE;
202 		rx_sg->lkey = device->pd->local_dma_lkey;
203 		rx_desc->rx_cqe.done = isert_recv_done;
204 	}
205 
206 	return 0;
207 
208 dma_map_fail:
209 	rx_desc = isert_conn->rx_descs;
210 	for (j = 0; j < i; j++, rx_desc++) {
211 		ib_dma_unmap_single(ib_dev, rx_desc->dma_addr,
212 				    ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
213 	}
214 	kfree(isert_conn->rx_descs);
215 	isert_conn->rx_descs = NULL;
216 	isert_err("conn %p failed to allocate rx descriptors\n", isert_conn);
217 	return -ENOMEM;
218 }
219 
220 static void
221 isert_free_rx_descriptors(struct isert_conn *isert_conn)
222 {
223 	struct ib_device *ib_dev = isert_conn->device->ib_device;
224 	struct iser_rx_desc *rx_desc;
225 	int i;
226 
227 	if (!isert_conn->rx_descs)
228 		return;
229 
230 	rx_desc = isert_conn->rx_descs;
231 	for (i = 0; i < ISERT_QP_MAX_RECV_DTOS; i++, rx_desc++)  {
232 		ib_dma_unmap_single(ib_dev, rx_desc->dma_addr,
233 				    ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
234 	}
235 
236 	kfree(isert_conn->rx_descs);
237 	isert_conn->rx_descs = NULL;
238 }
239 
240 static void
241 isert_free_comps(struct isert_device *device)
242 {
243 	int i;
244 
245 	for (i = 0; i < device->comps_used; i++) {
246 		struct isert_comp *comp = &device->comps[i];
247 
248 		if (comp->cq)
249 			ib_free_cq(comp->cq);
250 	}
251 	kfree(device->comps);
252 }
253 
254 static int
255 isert_alloc_comps(struct isert_device *device)
256 {
257 	int i, max_cqe, ret = 0;
258 
259 	device->comps_used = min(ISERT_MAX_CQ, min_t(int, num_online_cpus(),
260 				 device->ib_device->num_comp_vectors));
261 
262 	isert_info("Using %d CQs, %s supports %d vectors support "
263 		   "pi_capable %d\n",
264 		   device->comps_used, device->ib_device->name,
265 		   device->ib_device->num_comp_vectors,
266 		   device->pi_capable);
267 
268 	device->comps = kcalloc(device->comps_used, sizeof(struct isert_comp),
269 				GFP_KERNEL);
270 	if (!device->comps)
271 		return -ENOMEM;
272 
273 	max_cqe = min(ISER_MAX_CQ_LEN, device->ib_device->attrs.max_cqe);
274 
275 	for (i = 0; i < device->comps_used; i++) {
276 		struct isert_comp *comp = &device->comps[i];
277 
278 		comp->device = device;
279 		comp->cq = ib_alloc_cq(device->ib_device, comp, max_cqe, i,
280 				IB_POLL_WORKQUEUE);
281 		if (IS_ERR(comp->cq)) {
282 			isert_err("Unable to allocate cq\n");
283 			ret = PTR_ERR(comp->cq);
284 			comp->cq = NULL;
285 			goto out_cq;
286 		}
287 	}
288 
289 	return 0;
290 out_cq:
291 	isert_free_comps(device);
292 	return ret;
293 }
294 
295 static int
296 isert_create_device_ib_res(struct isert_device *device)
297 {
298 	struct ib_device *ib_dev = device->ib_device;
299 	int ret;
300 
301 	isert_dbg("devattr->max_sge: %d\n", ib_dev->attrs.max_sge);
302 	isert_dbg("devattr->max_sge_rd: %d\n", ib_dev->attrs.max_sge_rd);
303 
304 	ret = isert_alloc_comps(device);
305 	if (ret)
306 		goto out;
307 
308 	device->pd = ib_alloc_pd(ib_dev, 0);
309 	if (IS_ERR(device->pd)) {
310 		ret = PTR_ERR(device->pd);
311 		isert_err("failed to allocate pd, device %p, ret=%d\n",
312 			  device, ret);
313 		goto out_cq;
314 	}
315 
316 	/* Check signature cap */
317 	device->pi_capable = ib_dev->attrs.device_cap_flags &
318 			     IB_DEVICE_SIGNATURE_HANDOVER ? true : false;
319 
320 	return 0;
321 
322 out_cq:
323 	isert_free_comps(device);
324 out:
325 	if (ret > 0)
326 		ret = -EINVAL;
327 	return ret;
328 }
329 
330 static void
331 isert_free_device_ib_res(struct isert_device *device)
332 {
333 	isert_info("device %p\n", device);
334 
335 	ib_dealloc_pd(device->pd);
336 	isert_free_comps(device);
337 }
338 
339 static void
340 isert_device_put(struct isert_device *device)
341 {
342 	mutex_lock(&device_list_mutex);
343 	device->refcount--;
344 	isert_info("device %p refcount %d\n", device, device->refcount);
345 	if (!device->refcount) {
346 		isert_free_device_ib_res(device);
347 		list_del(&device->dev_node);
348 		kfree(device);
349 	}
350 	mutex_unlock(&device_list_mutex);
351 }
352 
353 static struct isert_device *
354 isert_device_get(struct rdma_cm_id *cma_id)
355 {
356 	struct isert_device *device;
357 	int ret;
358 
359 	mutex_lock(&device_list_mutex);
360 	list_for_each_entry(device, &device_list, dev_node) {
361 		if (device->ib_device->node_guid == cma_id->device->node_guid) {
362 			device->refcount++;
363 			isert_info("Found iser device %p refcount %d\n",
364 				   device, device->refcount);
365 			mutex_unlock(&device_list_mutex);
366 			return device;
367 		}
368 	}
369 
370 	device = kzalloc(sizeof(struct isert_device), GFP_KERNEL);
371 	if (!device) {
372 		mutex_unlock(&device_list_mutex);
373 		return ERR_PTR(-ENOMEM);
374 	}
375 
376 	INIT_LIST_HEAD(&device->dev_node);
377 
378 	device->ib_device = cma_id->device;
379 	ret = isert_create_device_ib_res(device);
380 	if (ret) {
381 		kfree(device);
382 		mutex_unlock(&device_list_mutex);
383 		return ERR_PTR(ret);
384 	}
385 
386 	device->refcount++;
387 	list_add_tail(&device->dev_node, &device_list);
388 	isert_info("Created a new iser device %p refcount %d\n",
389 		   device, device->refcount);
390 	mutex_unlock(&device_list_mutex);
391 
392 	return device;
393 }
394 
395 static void
396 isert_init_conn(struct isert_conn *isert_conn)
397 {
398 	isert_conn->state = ISER_CONN_INIT;
399 	INIT_LIST_HEAD(&isert_conn->node);
400 	init_completion(&isert_conn->login_comp);
401 	init_completion(&isert_conn->login_req_comp);
402 	init_waitqueue_head(&isert_conn->rem_wait);
403 	kref_init(&isert_conn->kref);
404 	mutex_init(&isert_conn->mutex);
405 	INIT_WORK(&isert_conn->release_work, isert_release_work);
406 }
407 
408 static void
409 isert_free_login_buf(struct isert_conn *isert_conn)
410 {
411 	struct ib_device *ib_dev = isert_conn->device->ib_device;
412 
413 	ib_dma_unmap_single(ib_dev, isert_conn->login_rsp_dma,
414 			    ISER_RX_PAYLOAD_SIZE, DMA_TO_DEVICE);
415 	kfree(isert_conn->login_rsp_buf);
416 
417 	ib_dma_unmap_single(ib_dev, isert_conn->login_req_dma,
418 			    ISER_RX_PAYLOAD_SIZE,
419 			    DMA_FROM_DEVICE);
420 	kfree(isert_conn->login_req_buf);
421 }
422 
423 static int
424 isert_alloc_login_buf(struct isert_conn *isert_conn,
425 		      struct ib_device *ib_dev)
426 {
427 	int ret;
428 
429 	isert_conn->login_req_buf = kzalloc(sizeof(*isert_conn->login_req_buf),
430 			GFP_KERNEL);
431 	if (!isert_conn->login_req_buf)
432 		return -ENOMEM;
433 
434 	isert_conn->login_req_dma = ib_dma_map_single(ib_dev,
435 				isert_conn->login_req_buf,
436 				ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
437 	ret = ib_dma_mapping_error(ib_dev, isert_conn->login_req_dma);
438 	if (ret) {
439 		isert_err("login_req_dma mapping error: %d\n", ret);
440 		isert_conn->login_req_dma = 0;
441 		goto out_free_login_req_buf;
442 	}
443 
444 	isert_conn->login_rsp_buf = kzalloc(ISER_RX_PAYLOAD_SIZE, GFP_KERNEL);
445 	if (!isert_conn->login_rsp_buf) {
446 		ret = -ENOMEM;
447 		goto out_unmap_login_req_buf;
448 	}
449 
450 	isert_conn->login_rsp_dma = ib_dma_map_single(ib_dev,
451 					isert_conn->login_rsp_buf,
452 					ISER_RX_PAYLOAD_SIZE, DMA_TO_DEVICE);
453 	ret = ib_dma_mapping_error(ib_dev, isert_conn->login_rsp_dma);
454 	if (ret) {
455 		isert_err("login_rsp_dma mapping error: %d\n", ret);
456 		isert_conn->login_rsp_dma = 0;
457 		goto out_free_login_rsp_buf;
458 	}
459 
460 	return 0;
461 
462 out_free_login_rsp_buf:
463 	kfree(isert_conn->login_rsp_buf);
464 out_unmap_login_req_buf:
465 	ib_dma_unmap_single(ib_dev, isert_conn->login_req_dma,
466 			    ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
467 out_free_login_req_buf:
468 	kfree(isert_conn->login_req_buf);
469 	return ret;
470 }
471 
472 static void
473 isert_set_nego_params(struct isert_conn *isert_conn,
474 		      struct rdma_conn_param *param)
475 {
476 	struct ib_device_attr *attr = &isert_conn->device->ib_device->attrs;
477 
478 	/* Set max inflight RDMA READ requests */
479 	isert_conn->initiator_depth = min_t(u8, param->initiator_depth,
480 				attr->max_qp_init_rd_atom);
481 	isert_dbg("Using initiator_depth: %u\n", isert_conn->initiator_depth);
482 
483 	if (param->private_data) {
484 		u8 flags = *(u8 *)param->private_data;
485 
486 		/*
487 		 * use remote invalidation if the both initiator
488 		 * and the HCA support it
489 		 */
490 		isert_conn->snd_w_inv = !(flags & ISER_SEND_W_INV_NOT_SUP) &&
491 					  (attr->device_cap_flags &
492 					   IB_DEVICE_MEM_MGT_EXTENSIONS);
493 		if (isert_conn->snd_w_inv)
494 			isert_info("Using remote invalidation\n");
495 	}
496 }
497 
498 static int
499 isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
500 {
501 	struct isert_np *isert_np = cma_id->context;
502 	struct iscsi_np *np = isert_np->np;
503 	struct isert_conn *isert_conn;
504 	struct isert_device *device;
505 	int ret = 0;
506 
507 	spin_lock_bh(&np->np_thread_lock);
508 	if (!np->enabled) {
509 		spin_unlock_bh(&np->np_thread_lock);
510 		isert_dbg("iscsi_np is not enabled, reject connect request\n");
511 		return rdma_reject(cma_id, NULL, 0);
512 	}
513 	spin_unlock_bh(&np->np_thread_lock);
514 
515 	isert_dbg("cma_id: %p, portal: %p\n",
516 		 cma_id, cma_id->context);
517 
518 	isert_conn = kzalloc(sizeof(struct isert_conn), GFP_KERNEL);
519 	if (!isert_conn)
520 		return -ENOMEM;
521 
522 	isert_init_conn(isert_conn);
523 	isert_conn->cm_id = cma_id;
524 
525 	ret = isert_alloc_login_buf(isert_conn, cma_id->device);
526 	if (ret)
527 		goto out;
528 
529 	device = isert_device_get(cma_id);
530 	if (IS_ERR(device)) {
531 		ret = PTR_ERR(device);
532 		goto out_rsp_dma_map;
533 	}
534 	isert_conn->device = device;
535 
536 	isert_set_nego_params(isert_conn, &event->param.conn);
537 
538 	ret = isert_conn_setup_qp(isert_conn, cma_id);
539 	if (ret)
540 		goto out_conn_dev;
541 
542 	ret = isert_login_post_recv(isert_conn);
543 	if (ret)
544 		goto out_conn_dev;
545 
546 	ret = isert_rdma_accept(isert_conn);
547 	if (ret)
548 		goto out_conn_dev;
549 
550 	mutex_lock(&isert_np->mutex);
551 	list_add_tail(&isert_conn->node, &isert_np->accepted);
552 	mutex_unlock(&isert_np->mutex);
553 
554 	return 0;
555 
556 out_conn_dev:
557 	isert_device_put(device);
558 out_rsp_dma_map:
559 	isert_free_login_buf(isert_conn);
560 out:
561 	kfree(isert_conn);
562 	rdma_reject(cma_id, NULL, 0);
563 	return ret;
564 }
565 
566 static void
567 isert_connect_release(struct isert_conn *isert_conn)
568 {
569 	struct isert_device *device = isert_conn->device;
570 
571 	isert_dbg("conn %p\n", isert_conn);
572 
573 	BUG_ON(!device);
574 
575 	isert_free_rx_descriptors(isert_conn);
576 	if (isert_conn->cm_id &&
577 	    !isert_conn->dev_removed)
578 		rdma_destroy_id(isert_conn->cm_id);
579 
580 	if (isert_conn->qp) {
581 		struct isert_comp *comp = isert_conn->qp->recv_cq->cq_context;
582 
583 		isert_comp_put(comp);
584 		ib_destroy_qp(isert_conn->qp);
585 	}
586 
587 	if (isert_conn->login_req_buf)
588 		isert_free_login_buf(isert_conn);
589 
590 	isert_device_put(device);
591 
592 	if (isert_conn->dev_removed)
593 		wake_up_interruptible(&isert_conn->rem_wait);
594 	else
595 		kfree(isert_conn);
596 }
597 
598 static void
599 isert_connected_handler(struct rdma_cm_id *cma_id)
600 {
601 	struct isert_conn *isert_conn = cma_id->qp->qp_context;
602 	struct isert_np *isert_np = cma_id->context;
603 
604 	isert_info("conn %p\n", isert_conn);
605 
606 	mutex_lock(&isert_conn->mutex);
607 	isert_conn->state = ISER_CONN_UP;
608 	kref_get(&isert_conn->kref);
609 	mutex_unlock(&isert_conn->mutex);
610 
611 	mutex_lock(&isert_np->mutex);
612 	list_move_tail(&isert_conn->node, &isert_np->pending);
613 	mutex_unlock(&isert_np->mutex);
614 
615 	isert_info("np %p: Allow accept_np to continue\n", isert_np);
616 	up(&isert_np->sem);
617 }
618 
619 static void
620 isert_release_kref(struct kref *kref)
621 {
622 	struct isert_conn *isert_conn = container_of(kref,
623 				struct isert_conn, kref);
624 
625 	isert_info("conn %p final kref %s/%d\n", isert_conn, current->comm,
626 		   current->pid);
627 
628 	isert_connect_release(isert_conn);
629 }
630 
631 static void
632 isert_put_conn(struct isert_conn *isert_conn)
633 {
634 	kref_put(&isert_conn->kref, isert_release_kref);
635 }
636 
637 static void
638 isert_handle_unbound_conn(struct isert_conn *isert_conn)
639 {
640 	struct isert_np *isert_np = isert_conn->cm_id->context;
641 
642 	mutex_lock(&isert_np->mutex);
643 	if (!list_empty(&isert_conn->node)) {
644 		/*
645 		 * This means iscsi doesn't know this connection
646 		 * so schedule a cleanup ourselves
647 		 */
648 		list_del_init(&isert_conn->node);
649 		isert_put_conn(isert_conn);
650 		queue_work(isert_release_wq, &isert_conn->release_work);
651 	}
652 	mutex_unlock(&isert_np->mutex);
653 }
654 
655 /**
656  * isert_conn_terminate() - Initiate connection termination
657  * @isert_conn: isert connection struct
658  *
659  * Notes:
660  * In case the connection state is BOUND, move state
661  * to TEMINATING and start teardown sequence (rdma_disconnect).
662  * In case the connection state is UP, complete flush as well.
663  *
664  * This routine must be called with mutex held. Thus it is
665  * safe to call multiple times.
666  */
667 static void
668 isert_conn_terminate(struct isert_conn *isert_conn)
669 {
670 	int err;
671 
672 	if (isert_conn->state >= ISER_CONN_TERMINATING)
673 		return;
674 
675 	isert_info("Terminating conn %p state %d\n",
676 		   isert_conn, isert_conn->state);
677 	isert_conn->state = ISER_CONN_TERMINATING;
678 	err = rdma_disconnect(isert_conn->cm_id);
679 	if (err)
680 		isert_warn("Failed rdma_disconnect isert_conn %p\n",
681 			   isert_conn);
682 }
683 
684 static int
685 isert_np_cma_handler(struct isert_np *isert_np,
686 		     enum rdma_cm_event_type event)
687 {
688 	isert_dbg("%s (%d): isert np %p\n",
689 		  rdma_event_msg(event), event, isert_np);
690 
691 	switch (event) {
692 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
693 		isert_np->cm_id = NULL;
694 		break;
695 	case RDMA_CM_EVENT_ADDR_CHANGE:
696 		isert_np->cm_id = isert_setup_id(isert_np);
697 		if (IS_ERR(isert_np->cm_id)) {
698 			isert_err("isert np %p setup id failed: %ld\n",
699 				  isert_np, PTR_ERR(isert_np->cm_id));
700 			isert_np->cm_id = NULL;
701 		}
702 		break;
703 	default:
704 		isert_err("isert np %p Unexpected event %d\n",
705 			  isert_np, event);
706 	}
707 
708 	return -1;
709 }
710 
711 static int
712 isert_disconnected_handler(struct rdma_cm_id *cma_id,
713 			   enum rdma_cm_event_type event)
714 {
715 	struct isert_conn *isert_conn = cma_id->qp->qp_context;
716 
717 	mutex_lock(&isert_conn->mutex);
718 	switch (isert_conn->state) {
719 	case ISER_CONN_TERMINATING:
720 		break;
721 	case ISER_CONN_UP:
722 		isert_conn_terminate(isert_conn);
723 		ib_drain_qp(isert_conn->qp);
724 		isert_handle_unbound_conn(isert_conn);
725 		break;
726 	case ISER_CONN_BOUND:
727 	case ISER_CONN_FULL_FEATURE: /* FALLTHRU */
728 		iscsit_cause_connection_reinstatement(isert_conn->conn, 0);
729 		break;
730 	default:
731 		isert_warn("conn %p terminating in state %d\n",
732 			   isert_conn, isert_conn->state);
733 	}
734 	mutex_unlock(&isert_conn->mutex);
735 
736 	return 0;
737 }
738 
739 static int
740 isert_connect_error(struct rdma_cm_id *cma_id)
741 {
742 	struct isert_conn *isert_conn = cma_id->qp->qp_context;
743 
744 	list_del_init(&isert_conn->node);
745 	isert_conn->cm_id = NULL;
746 	isert_put_conn(isert_conn);
747 
748 	return -1;
749 }
750 
751 static int
752 isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
753 {
754 	struct isert_np *isert_np = cma_id->context;
755 	struct isert_conn *isert_conn;
756 	int ret = 0;
757 
758 	isert_info("%s (%d): status %d id %p np %p\n",
759 		   rdma_event_msg(event->event), event->event,
760 		   event->status, cma_id, cma_id->context);
761 
762 	if (isert_np->cm_id == cma_id)
763 		return isert_np_cma_handler(cma_id->context, event->event);
764 
765 	switch (event->event) {
766 	case RDMA_CM_EVENT_CONNECT_REQUEST:
767 		ret = isert_connect_request(cma_id, event);
768 		if (ret)
769 			isert_err("failed handle connect request %d\n", ret);
770 		break;
771 	case RDMA_CM_EVENT_ESTABLISHED:
772 		isert_connected_handler(cma_id);
773 		break;
774 	case RDMA_CM_EVENT_ADDR_CHANGE:    /* FALLTHRU */
775 	case RDMA_CM_EVENT_DISCONNECTED:   /* FALLTHRU */
776 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:  /* FALLTHRU */
777 		ret = isert_disconnected_handler(cma_id, event->event);
778 		break;
779 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
780 		isert_conn = cma_id->qp->qp_context;
781 		isert_conn->dev_removed = true;
782 		isert_disconnected_handler(cma_id, event->event);
783 		wait_event_interruptible(isert_conn->rem_wait,
784 					 isert_conn->state == ISER_CONN_DOWN);
785 		kfree(isert_conn);
786 		/*
787 		 * return non-zero from the callback to destroy
788 		 * the rdma cm id
789 		 */
790 		return 1;
791 	case RDMA_CM_EVENT_REJECTED:       /* FALLTHRU */
792 		isert_info("Connection rejected: %s\n",
793 			   rdma_reject_msg(cma_id, event->status));
794 	case RDMA_CM_EVENT_UNREACHABLE:    /* FALLTHRU */
795 	case RDMA_CM_EVENT_CONNECT_ERROR:
796 		ret = isert_connect_error(cma_id);
797 		break;
798 	default:
799 		isert_err("Unhandled RDMA CMA event: %d\n", event->event);
800 		break;
801 	}
802 
803 	return ret;
804 }
805 
806 static int
807 isert_post_recvm(struct isert_conn *isert_conn, u32 count)
808 {
809 	struct ib_recv_wr *rx_wr, *rx_wr_failed;
810 	int i, ret;
811 	struct iser_rx_desc *rx_desc;
812 
813 	for (rx_wr = isert_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
814 		rx_desc = &isert_conn->rx_descs[i];
815 
816 		rx_wr->wr_cqe = &rx_desc->rx_cqe;
817 		rx_wr->sg_list = &rx_desc->rx_sg;
818 		rx_wr->num_sge = 1;
819 		rx_wr->next = rx_wr + 1;
820 	}
821 	rx_wr--;
822 	rx_wr->next = NULL; /* mark end of work requests list */
823 
824 	ret = ib_post_recv(isert_conn->qp, isert_conn->rx_wr,
825 			   &rx_wr_failed);
826 	if (ret)
827 		isert_err("ib_post_recv() failed with ret: %d\n", ret);
828 
829 	return ret;
830 }
831 
832 static int
833 isert_post_recv(struct isert_conn *isert_conn, struct iser_rx_desc *rx_desc)
834 {
835 	struct ib_recv_wr *rx_wr_failed, rx_wr;
836 	int ret;
837 
838 	rx_wr.wr_cqe = &rx_desc->rx_cqe;
839 	rx_wr.sg_list = &rx_desc->rx_sg;
840 	rx_wr.num_sge = 1;
841 	rx_wr.next = NULL;
842 
843 	ret = ib_post_recv(isert_conn->qp, &rx_wr, &rx_wr_failed);
844 	if (ret)
845 		isert_err("ib_post_recv() failed with ret: %d\n", ret);
846 
847 	return ret;
848 }
849 
850 static int
851 isert_login_post_send(struct isert_conn *isert_conn, struct iser_tx_desc *tx_desc)
852 {
853 	struct ib_device *ib_dev = isert_conn->cm_id->device;
854 	struct ib_send_wr send_wr, *send_wr_failed;
855 	int ret;
856 
857 	ib_dma_sync_single_for_device(ib_dev, tx_desc->dma_addr,
858 				      ISER_HEADERS_LEN, DMA_TO_DEVICE);
859 
860 	tx_desc->tx_cqe.done = isert_login_send_done;
861 
862 	send_wr.next	= NULL;
863 	send_wr.wr_cqe	= &tx_desc->tx_cqe;
864 	send_wr.sg_list	= tx_desc->tx_sg;
865 	send_wr.num_sge	= tx_desc->num_sge;
866 	send_wr.opcode	= IB_WR_SEND;
867 	send_wr.send_flags = IB_SEND_SIGNALED;
868 
869 	ret = ib_post_send(isert_conn->qp, &send_wr, &send_wr_failed);
870 	if (ret)
871 		isert_err("ib_post_send() failed, ret: %d\n", ret);
872 
873 	return ret;
874 }
875 
876 static void
877 isert_create_send_desc(struct isert_conn *isert_conn,
878 		       struct isert_cmd *isert_cmd,
879 		       struct iser_tx_desc *tx_desc)
880 {
881 	struct isert_device *device = isert_conn->device;
882 	struct ib_device *ib_dev = device->ib_device;
883 
884 	ib_dma_sync_single_for_cpu(ib_dev, tx_desc->dma_addr,
885 				   ISER_HEADERS_LEN, DMA_TO_DEVICE);
886 
887 	memset(&tx_desc->iser_header, 0, sizeof(struct iser_ctrl));
888 	tx_desc->iser_header.flags = ISCSI_CTRL;
889 
890 	tx_desc->num_sge = 1;
891 
892 	if (tx_desc->tx_sg[0].lkey != device->pd->local_dma_lkey) {
893 		tx_desc->tx_sg[0].lkey = device->pd->local_dma_lkey;
894 		isert_dbg("tx_desc %p lkey mismatch, fixing\n", tx_desc);
895 	}
896 }
897 
898 static int
899 isert_init_tx_hdrs(struct isert_conn *isert_conn,
900 		   struct iser_tx_desc *tx_desc)
901 {
902 	struct isert_device *device = isert_conn->device;
903 	struct ib_device *ib_dev = device->ib_device;
904 	u64 dma_addr;
905 
906 	dma_addr = ib_dma_map_single(ib_dev, (void *)tx_desc,
907 			ISER_HEADERS_LEN, DMA_TO_DEVICE);
908 	if (ib_dma_mapping_error(ib_dev, dma_addr)) {
909 		isert_err("ib_dma_mapping_error() failed\n");
910 		return -ENOMEM;
911 	}
912 
913 	tx_desc->dma_addr = dma_addr;
914 	tx_desc->tx_sg[0].addr	= tx_desc->dma_addr;
915 	tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;
916 	tx_desc->tx_sg[0].lkey = device->pd->local_dma_lkey;
917 
918 	isert_dbg("Setup tx_sg[0].addr: 0x%llx length: %u lkey: 0x%x\n",
919 		  tx_desc->tx_sg[0].addr, tx_desc->tx_sg[0].length,
920 		  tx_desc->tx_sg[0].lkey);
921 
922 	return 0;
923 }
924 
925 static void
926 isert_init_send_wr(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
927 		   struct ib_send_wr *send_wr)
928 {
929 	struct iser_tx_desc *tx_desc = &isert_cmd->tx_desc;
930 
931 	tx_desc->tx_cqe.done = isert_send_done;
932 	send_wr->wr_cqe = &tx_desc->tx_cqe;
933 
934 	if (isert_conn->snd_w_inv && isert_cmd->inv_rkey) {
935 		send_wr->opcode  = IB_WR_SEND_WITH_INV;
936 		send_wr->ex.invalidate_rkey = isert_cmd->inv_rkey;
937 	} else {
938 		send_wr->opcode = IB_WR_SEND;
939 	}
940 
941 	send_wr->sg_list = &tx_desc->tx_sg[0];
942 	send_wr->num_sge = isert_cmd->tx_desc.num_sge;
943 	send_wr->send_flags = IB_SEND_SIGNALED;
944 }
945 
946 static int
947 isert_login_post_recv(struct isert_conn *isert_conn)
948 {
949 	struct ib_recv_wr rx_wr, *rx_wr_fail;
950 	struct ib_sge sge;
951 	int ret;
952 
953 	memset(&sge, 0, sizeof(struct ib_sge));
954 	sge.addr = isert_conn->login_req_dma;
955 	sge.length = ISER_RX_PAYLOAD_SIZE;
956 	sge.lkey = isert_conn->device->pd->local_dma_lkey;
957 
958 	isert_dbg("Setup sge: addr: %llx length: %d 0x%08x\n",
959 		sge.addr, sge.length, sge.lkey);
960 
961 	isert_conn->login_req_buf->rx_cqe.done = isert_login_recv_done;
962 
963 	memset(&rx_wr, 0, sizeof(struct ib_recv_wr));
964 	rx_wr.wr_cqe = &isert_conn->login_req_buf->rx_cqe;
965 	rx_wr.sg_list = &sge;
966 	rx_wr.num_sge = 1;
967 
968 	ret = ib_post_recv(isert_conn->qp, &rx_wr, &rx_wr_fail);
969 	if (ret)
970 		isert_err("ib_post_recv() failed: %d\n", ret);
971 
972 	return ret;
973 }
974 
975 static int
976 isert_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
977 		   u32 length)
978 {
979 	struct isert_conn *isert_conn = conn->context;
980 	struct isert_device *device = isert_conn->device;
981 	struct ib_device *ib_dev = device->ib_device;
982 	struct iser_tx_desc *tx_desc = &isert_conn->login_tx_desc;
983 	int ret;
984 
985 	isert_create_send_desc(isert_conn, NULL, tx_desc);
986 
987 	memcpy(&tx_desc->iscsi_header, &login->rsp[0],
988 	       sizeof(struct iscsi_hdr));
989 
990 	isert_init_tx_hdrs(isert_conn, tx_desc);
991 
992 	if (length > 0) {
993 		struct ib_sge *tx_dsg = &tx_desc->tx_sg[1];
994 
995 		ib_dma_sync_single_for_cpu(ib_dev, isert_conn->login_rsp_dma,
996 					   length, DMA_TO_DEVICE);
997 
998 		memcpy(isert_conn->login_rsp_buf, login->rsp_buf, length);
999 
1000 		ib_dma_sync_single_for_device(ib_dev, isert_conn->login_rsp_dma,
1001 					      length, DMA_TO_DEVICE);
1002 
1003 		tx_dsg->addr	= isert_conn->login_rsp_dma;
1004 		tx_dsg->length	= length;
1005 		tx_dsg->lkey	= isert_conn->device->pd->local_dma_lkey;
1006 		tx_desc->num_sge = 2;
1007 	}
1008 	if (!login->login_failed) {
1009 		if (login->login_complete) {
1010 			ret = isert_alloc_rx_descriptors(isert_conn);
1011 			if (ret)
1012 				return ret;
1013 
1014 			ret = isert_post_recvm(isert_conn,
1015 					       ISERT_QP_MAX_RECV_DTOS);
1016 			if (ret)
1017 				return ret;
1018 
1019 			/* Now we are in FULL_FEATURE phase */
1020 			mutex_lock(&isert_conn->mutex);
1021 			isert_conn->state = ISER_CONN_FULL_FEATURE;
1022 			mutex_unlock(&isert_conn->mutex);
1023 			goto post_send;
1024 		}
1025 
1026 		ret = isert_login_post_recv(isert_conn);
1027 		if (ret)
1028 			return ret;
1029 	}
1030 post_send:
1031 	ret = isert_login_post_send(isert_conn, tx_desc);
1032 	if (ret)
1033 		return ret;
1034 
1035 	return 0;
1036 }
1037 
1038 static void
1039 isert_rx_login_req(struct isert_conn *isert_conn)
1040 {
1041 	struct iser_rx_desc *rx_desc = isert_conn->login_req_buf;
1042 	int rx_buflen = isert_conn->login_req_len;
1043 	struct iscsi_conn *conn = isert_conn->conn;
1044 	struct iscsi_login *login = conn->conn_login;
1045 	int size;
1046 
1047 	isert_info("conn %p\n", isert_conn);
1048 
1049 	WARN_ON_ONCE(!login);
1050 
1051 	if (login->first_request) {
1052 		struct iscsi_login_req *login_req =
1053 			(struct iscsi_login_req *)&rx_desc->iscsi_header;
1054 		/*
1055 		 * Setup the initial iscsi_login values from the leading
1056 		 * login request PDU.
1057 		 */
1058 		login->leading_connection = (!login_req->tsih) ? 1 : 0;
1059 		login->current_stage =
1060 			(login_req->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK)
1061 			 >> 2;
1062 		login->version_min	= login_req->min_version;
1063 		login->version_max	= login_req->max_version;
1064 		memcpy(login->isid, login_req->isid, 6);
1065 		login->cmd_sn		= be32_to_cpu(login_req->cmdsn);
1066 		login->init_task_tag	= login_req->itt;
1067 		login->initial_exp_statsn = be32_to_cpu(login_req->exp_statsn);
1068 		login->cid		= be16_to_cpu(login_req->cid);
1069 		login->tsih		= be16_to_cpu(login_req->tsih);
1070 	}
1071 
1072 	memcpy(&login->req[0], (void *)&rx_desc->iscsi_header, ISCSI_HDR_LEN);
1073 
1074 	size = min(rx_buflen, MAX_KEY_VALUE_PAIRS);
1075 	isert_dbg("Using login payload size: %d, rx_buflen: %d "
1076 		  "MAX_KEY_VALUE_PAIRS: %d\n", size, rx_buflen,
1077 		  MAX_KEY_VALUE_PAIRS);
1078 	memcpy(login->req_buf, &rx_desc->data[0], size);
1079 
1080 	if (login->first_request) {
1081 		complete(&isert_conn->login_comp);
1082 		return;
1083 	}
1084 	schedule_delayed_work(&conn->login_work, 0);
1085 }
1086 
1087 static struct iscsi_cmd
1088 *isert_allocate_cmd(struct iscsi_conn *conn, struct iser_rx_desc *rx_desc)
1089 {
1090 	struct isert_conn *isert_conn = conn->context;
1091 	struct isert_cmd *isert_cmd;
1092 	struct iscsi_cmd *cmd;
1093 
1094 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
1095 	if (!cmd) {
1096 		isert_err("Unable to allocate iscsi_cmd + isert_cmd\n");
1097 		return NULL;
1098 	}
1099 	isert_cmd = iscsit_priv_cmd(cmd);
1100 	isert_cmd->conn = isert_conn;
1101 	isert_cmd->iscsi_cmd = cmd;
1102 	isert_cmd->rx_desc = rx_desc;
1103 
1104 	return cmd;
1105 }
1106 
1107 static int
1108 isert_handle_scsi_cmd(struct isert_conn *isert_conn,
1109 		      struct isert_cmd *isert_cmd, struct iscsi_cmd *cmd,
1110 		      struct iser_rx_desc *rx_desc, unsigned char *buf)
1111 {
1112 	struct iscsi_conn *conn = isert_conn->conn;
1113 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)buf;
1114 	int imm_data, imm_data_len, unsol_data, sg_nents, rc;
1115 	bool dump_payload = false;
1116 	unsigned int data_len;
1117 
1118 	rc = iscsit_setup_scsi_cmd(conn, cmd, buf);
1119 	if (rc < 0)
1120 		return rc;
1121 
1122 	imm_data = cmd->immediate_data;
1123 	imm_data_len = cmd->first_burst_len;
1124 	unsol_data = cmd->unsolicited_data;
1125 	data_len = cmd->se_cmd.data_length;
1126 
1127 	if (imm_data && imm_data_len == data_len)
1128 		cmd->se_cmd.se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1129 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
1130 	if (rc < 0) {
1131 		return 0;
1132 	} else if (rc > 0) {
1133 		dump_payload = true;
1134 		goto sequence_cmd;
1135 	}
1136 
1137 	if (!imm_data)
1138 		return 0;
1139 
1140 	if (imm_data_len != data_len) {
1141 		sg_nents = max(1UL, DIV_ROUND_UP(imm_data_len, PAGE_SIZE));
1142 		sg_copy_from_buffer(cmd->se_cmd.t_data_sg, sg_nents,
1143 				    &rx_desc->data[0], imm_data_len);
1144 		isert_dbg("Copy Immediate sg_nents: %u imm_data_len: %d\n",
1145 			  sg_nents, imm_data_len);
1146 	} else {
1147 		sg_init_table(&isert_cmd->sg, 1);
1148 		cmd->se_cmd.t_data_sg = &isert_cmd->sg;
1149 		cmd->se_cmd.t_data_nents = 1;
1150 		sg_set_buf(&isert_cmd->sg, &rx_desc->data[0], imm_data_len);
1151 		isert_dbg("Transfer Immediate imm_data_len: %d\n",
1152 			  imm_data_len);
1153 	}
1154 
1155 	cmd->write_data_done += imm_data_len;
1156 
1157 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
1158 		spin_lock_bh(&cmd->istate_lock);
1159 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
1160 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
1161 		spin_unlock_bh(&cmd->istate_lock);
1162 	}
1163 
1164 sequence_cmd:
1165 	rc = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
1166 
1167 	if (!rc && dump_payload == false && unsol_data)
1168 		iscsit_set_unsoliticed_dataout(cmd);
1169 	else if (dump_payload && imm_data)
1170 		target_put_sess_cmd(&cmd->se_cmd);
1171 
1172 	return 0;
1173 }
1174 
1175 static int
1176 isert_handle_iscsi_dataout(struct isert_conn *isert_conn,
1177 			   struct iser_rx_desc *rx_desc, unsigned char *buf)
1178 {
1179 	struct scatterlist *sg_start;
1180 	struct iscsi_conn *conn = isert_conn->conn;
1181 	struct iscsi_cmd *cmd = NULL;
1182 	struct iscsi_data *hdr = (struct iscsi_data *)buf;
1183 	u32 unsol_data_len = ntoh24(hdr->dlength);
1184 	int rc, sg_nents, sg_off, page_off;
1185 
1186 	rc = iscsit_check_dataout_hdr(conn, buf, &cmd);
1187 	if (rc < 0)
1188 		return rc;
1189 	else if (!cmd)
1190 		return 0;
1191 	/*
1192 	 * FIXME: Unexpected unsolicited_data out
1193 	 */
1194 	if (!cmd->unsolicited_data) {
1195 		isert_err("Received unexpected solicited data payload\n");
1196 		dump_stack();
1197 		return -1;
1198 	}
1199 
1200 	isert_dbg("Unsolicited DataOut unsol_data_len: %u, "
1201 		  "write_data_done: %u, data_length: %u\n",
1202 		  unsol_data_len,  cmd->write_data_done,
1203 		  cmd->se_cmd.data_length);
1204 
1205 	sg_off = cmd->write_data_done / PAGE_SIZE;
1206 	sg_start = &cmd->se_cmd.t_data_sg[sg_off];
1207 	sg_nents = max(1UL, DIV_ROUND_UP(unsol_data_len, PAGE_SIZE));
1208 	page_off = cmd->write_data_done % PAGE_SIZE;
1209 	/*
1210 	 * FIXME: Non page-aligned unsolicited_data out
1211 	 */
1212 	if (page_off) {
1213 		isert_err("unexpected non-page aligned data payload\n");
1214 		dump_stack();
1215 		return -1;
1216 	}
1217 	isert_dbg("Copying DataOut: sg_start: %p, sg_off: %u "
1218 		  "sg_nents: %u from %p %u\n", sg_start, sg_off,
1219 		  sg_nents, &rx_desc->data[0], unsol_data_len);
1220 
1221 	sg_copy_from_buffer(sg_start, sg_nents, &rx_desc->data[0],
1222 			    unsol_data_len);
1223 
1224 	rc = iscsit_check_dataout_payload(cmd, hdr, false);
1225 	if (rc < 0)
1226 		return rc;
1227 
1228 	/*
1229 	 * multiple data-outs on the same command can arrive -
1230 	 * so post the buffer before hand
1231 	 */
1232 	rc = isert_post_recv(isert_conn, rx_desc);
1233 	if (rc) {
1234 		isert_err("ib_post_recv failed with %d\n", rc);
1235 		return rc;
1236 	}
1237 	return 0;
1238 }
1239 
1240 static int
1241 isert_handle_nop_out(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
1242 		     struct iscsi_cmd *cmd, struct iser_rx_desc *rx_desc,
1243 		     unsigned char *buf)
1244 {
1245 	struct iscsi_conn *conn = isert_conn->conn;
1246 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)buf;
1247 	int rc;
1248 
1249 	rc = iscsit_setup_nop_out(conn, cmd, hdr);
1250 	if (rc < 0)
1251 		return rc;
1252 	/*
1253 	 * FIXME: Add support for NOPOUT payload using unsolicited RDMA payload
1254 	 */
1255 
1256 	return iscsit_process_nop_out(conn, cmd, hdr);
1257 }
1258 
1259 static int
1260 isert_handle_text_cmd(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
1261 		      struct iscsi_cmd *cmd, struct iser_rx_desc *rx_desc,
1262 		      struct iscsi_text *hdr)
1263 {
1264 	struct iscsi_conn *conn = isert_conn->conn;
1265 	u32 payload_length = ntoh24(hdr->dlength);
1266 	int rc;
1267 	unsigned char *text_in = NULL;
1268 
1269 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
1270 	if (rc < 0)
1271 		return rc;
1272 
1273 	if (payload_length) {
1274 		text_in = kzalloc(payload_length, GFP_KERNEL);
1275 		if (!text_in)
1276 			return -ENOMEM;
1277 	}
1278 	cmd->text_in_ptr = text_in;
1279 
1280 	memcpy(cmd->text_in_ptr, &rx_desc->data[0], payload_length);
1281 
1282 	return iscsit_process_text_cmd(conn, cmd, hdr);
1283 }
1284 
1285 static int
1286 isert_rx_opcode(struct isert_conn *isert_conn, struct iser_rx_desc *rx_desc,
1287 		uint32_t read_stag, uint64_t read_va,
1288 		uint32_t write_stag, uint64_t write_va)
1289 {
1290 	struct iscsi_hdr *hdr = &rx_desc->iscsi_header;
1291 	struct iscsi_conn *conn = isert_conn->conn;
1292 	struct iscsi_cmd *cmd;
1293 	struct isert_cmd *isert_cmd;
1294 	int ret = -EINVAL;
1295 	u8 opcode = (hdr->opcode & ISCSI_OPCODE_MASK);
1296 
1297 	if (conn->sess->sess_ops->SessionType &&
1298 	   (!(opcode & ISCSI_OP_TEXT) || !(opcode & ISCSI_OP_LOGOUT))) {
1299 		isert_err("Got illegal opcode: 0x%02x in SessionType=Discovery,"
1300 			  " ignoring\n", opcode);
1301 		return 0;
1302 	}
1303 
1304 	switch (opcode) {
1305 	case ISCSI_OP_SCSI_CMD:
1306 		cmd = isert_allocate_cmd(conn, rx_desc);
1307 		if (!cmd)
1308 			break;
1309 
1310 		isert_cmd = iscsit_priv_cmd(cmd);
1311 		isert_cmd->read_stag = read_stag;
1312 		isert_cmd->read_va = read_va;
1313 		isert_cmd->write_stag = write_stag;
1314 		isert_cmd->write_va = write_va;
1315 		isert_cmd->inv_rkey = read_stag ? read_stag : write_stag;
1316 
1317 		ret = isert_handle_scsi_cmd(isert_conn, isert_cmd, cmd,
1318 					rx_desc, (unsigned char *)hdr);
1319 		break;
1320 	case ISCSI_OP_NOOP_OUT:
1321 		cmd = isert_allocate_cmd(conn, rx_desc);
1322 		if (!cmd)
1323 			break;
1324 
1325 		isert_cmd = iscsit_priv_cmd(cmd);
1326 		ret = isert_handle_nop_out(isert_conn, isert_cmd, cmd,
1327 					   rx_desc, (unsigned char *)hdr);
1328 		break;
1329 	case ISCSI_OP_SCSI_DATA_OUT:
1330 		ret = isert_handle_iscsi_dataout(isert_conn, rx_desc,
1331 						(unsigned char *)hdr);
1332 		break;
1333 	case ISCSI_OP_SCSI_TMFUNC:
1334 		cmd = isert_allocate_cmd(conn, rx_desc);
1335 		if (!cmd)
1336 			break;
1337 
1338 		ret = iscsit_handle_task_mgt_cmd(conn, cmd,
1339 						(unsigned char *)hdr);
1340 		break;
1341 	case ISCSI_OP_LOGOUT:
1342 		cmd = isert_allocate_cmd(conn, rx_desc);
1343 		if (!cmd)
1344 			break;
1345 
1346 		ret = iscsit_handle_logout_cmd(conn, cmd, (unsigned char *)hdr);
1347 		break;
1348 	case ISCSI_OP_TEXT:
1349 		if (be32_to_cpu(hdr->ttt) != 0xFFFFFFFF)
1350 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
1351 		else
1352 			cmd = isert_allocate_cmd(conn, rx_desc);
1353 
1354 		if (!cmd)
1355 			break;
1356 
1357 		isert_cmd = iscsit_priv_cmd(cmd);
1358 		ret = isert_handle_text_cmd(isert_conn, isert_cmd, cmd,
1359 					    rx_desc, (struct iscsi_text *)hdr);
1360 		break;
1361 	default:
1362 		isert_err("Got unknown iSCSI OpCode: 0x%02x\n", opcode);
1363 		dump_stack();
1364 		break;
1365 	}
1366 
1367 	return ret;
1368 }
1369 
1370 static void
1371 isert_print_wc(struct ib_wc *wc, const char *type)
1372 {
1373 	if (wc->status != IB_WC_WR_FLUSH_ERR)
1374 		isert_err("%s failure: %s (%d) vend_err %x\n", type,
1375 			  ib_wc_status_msg(wc->status), wc->status,
1376 			  wc->vendor_err);
1377 	else
1378 		isert_dbg("%s failure: %s (%d)\n", type,
1379 			  ib_wc_status_msg(wc->status), wc->status);
1380 }
1381 
1382 static void
1383 isert_recv_done(struct ib_cq *cq, struct ib_wc *wc)
1384 {
1385 	struct isert_conn *isert_conn = wc->qp->qp_context;
1386 	struct ib_device *ib_dev = isert_conn->cm_id->device;
1387 	struct iser_rx_desc *rx_desc = cqe_to_rx_desc(wc->wr_cqe);
1388 	struct iscsi_hdr *hdr = &rx_desc->iscsi_header;
1389 	struct iser_ctrl *iser_ctrl = &rx_desc->iser_header;
1390 	uint64_t read_va = 0, write_va = 0;
1391 	uint32_t read_stag = 0, write_stag = 0;
1392 
1393 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
1394 		isert_print_wc(wc, "recv");
1395 		if (wc->status != IB_WC_WR_FLUSH_ERR)
1396 			iscsit_cause_connection_reinstatement(isert_conn->conn, 0);
1397 		return;
1398 	}
1399 
1400 	ib_dma_sync_single_for_cpu(ib_dev, rx_desc->dma_addr,
1401 			ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
1402 
1403 	isert_dbg("DMA: 0x%llx, iSCSI opcode: 0x%02x, ITT: 0x%08x, flags: 0x%02x dlen: %d\n",
1404 		 rx_desc->dma_addr, hdr->opcode, hdr->itt, hdr->flags,
1405 		 (int)(wc->byte_len - ISER_HEADERS_LEN));
1406 
1407 	switch (iser_ctrl->flags & 0xF0) {
1408 	case ISCSI_CTRL:
1409 		if (iser_ctrl->flags & ISER_RSV) {
1410 			read_stag = be32_to_cpu(iser_ctrl->read_stag);
1411 			read_va = be64_to_cpu(iser_ctrl->read_va);
1412 			isert_dbg("ISER_RSV: read_stag: 0x%x read_va: 0x%llx\n",
1413 				  read_stag, (unsigned long long)read_va);
1414 		}
1415 		if (iser_ctrl->flags & ISER_WSV) {
1416 			write_stag = be32_to_cpu(iser_ctrl->write_stag);
1417 			write_va = be64_to_cpu(iser_ctrl->write_va);
1418 			isert_dbg("ISER_WSV: write_stag: 0x%x write_va: 0x%llx\n",
1419 				  write_stag, (unsigned long long)write_va);
1420 		}
1421 
1422 		isert_dbg("ISER ISCSI_CTRL PDU\n");
1423 		break;
1424 	case ISER_HELLO:
1425 		isert_err("iSER Hello message\n");
1426 		break;
1427 	default:
1428 		isert_warn("Unknown iSER hdr flags: 0x%02x\n", iser_ctrl->flags);
1429 		break;
1430 	}
1431 
1432 	isert_rx_opcode(isert_conn, rx_desc,
1433 			read_stag, read_va, write_stag, write_va);
1434 
1435 	ib_dma_sync_single_for_device(ib_dev, rx_desc->dma_addr,
1436 			ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
1437 }
1438 
1439 static void
1440 isert_login_recv_done(struct ib_cq *cq, struct ib_wc *wc)
1441 {
1442 	struct isert_conn *isert_conn = wc->qp->qp_context;
1443 	struct ib_device *ib_dev = isert_conn->cm_id->device;
1444 
1445 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
1446 		isert_print_wc(wc, "login recv");
1447 		return;
1448 	}
1449 
1450 	ib_dma_sync_single_for_cpu(ib_dev, isert_conn->login_req_dma,
1451 			ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
1452 
1453 	isert_conn->login_req_len = wc->byte_len - ISER_HEADERS_LEN;
1454 
1455 	if (isert_conn->conn) {
1456 		struct iscsi_login *login = isert_conn->conn->conn_login;
1457 
1458 		if (login && !login->first_request)
1459 			isert_rx_login_req(isert_conn);
1460 	}
1461 
1462 	mutex_lock(&isert_conn->mutex);
1463 	complete(&isert_conn->login_req_comp);
1464 	mutex_unlock(&isert_conn->mutex);
1465 
1466 	ib_dma_sync_single_for_device(ib_dev, isert_conn->login_req_dma,
1467 				ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
1468 }
1469 
1470 static void
1471 isert_rdma_rw_ctx_destroy(struct isert_cmd *cmd, struct isert_conn *conn)
1472 {
1473 	struct se_cmd *se_cmd = &cmd->iscsi_cmd->se_cmd;
1474 	enum dma_data_direction dir = target_reverse_dma_direction(se_cmd);
1475 
1476 	if (!cmd->rw.nr_ops)
1477 		return;
1478 
1479 	if (isert_prot_cmd(conn, se_cmd)) {
1480 		rdma_rw_ctx_destroy_signature(&cmd->rw, conn->qp,
1481 				conn->cm_id->port_num, se_cmd->t_data_sg,
1482 				se_cmd->t_data_nents, se_cmd->t_prot_sg,
1483 				se_cmd->t_prot_nents, dir);
1484 	} else {
1485 		rdma_rw_ctx_destroy(&cmd->rw, conn->qp, conn->cm_id->port_num,
1486 				se_cmd->t_data_sg, se_cmd->t_data_nents, dir);
1487 	}
1488 
1489 	cmd->rw.nr_ops = 0;
1490 }
1491 
1492 static void
1493 isert_put_cmd(struct isert_cmd *isert_cmd, bool comp_err)
1494 {
1495 	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
1496 	struct isert_conn *isert_conn = isert_cmd->conn;
1497 	struct iscsi_conn *conn = isert_conn->conn;
1498 	struct iscsi_text_rsp *hdr;
1499 
1500 	isert_dbg("Cmd %p\n", isert_cmd);
1501 
1502 	switch (cmd->iscsi_opcode) {
1503 	case ISCSI_OP_SCSI_CMD:
1504 		spin_lock_bh(&conn->cmd_lock);
1505 		if (!list_empty(&cmd->i_conn_node))
1506 			list_del_init(&cmd->i_conn_node);
1507 		spin_unlock_bh(&conn->cmd_lock);
1508 
1509 		if (cmd->data_direction == DMA_TO_DEVICE) {
1510 			iscsit_stop_dataout_timer(cmd);
1511 			/*
1512 			 * Check for special case during comp_err where
1513 			 * WRITE_PENDING has been handed off from core,
1514 			 * but requires an extra target_put_sess_cmd()
1515 			 * before transport_generic_free_cmd() below.
1516 			 */
1517 			if (comp_err &&
1518 			    cmd->se_cmd.t_state == TRANSPORT_WRITE_PENDING) {
1519 				struct se_cmd *se_cmd = &cmd->se_cmd;
1520 
1521 				target_put_sess_cmd(se_cmd);
1522 			}
1523 		}
1524 
1525 		isert_rdma_rw_ctx_destroy(isert_cmd, isert_conn);
1526 		transport_generic_free_cmd(&cmd->se_cmd, 0);
1527 		break;
1528 	case ISCSI_OP_SCSI_TMFUNC:
1529 		spin_lock_bh(&conn->cmd_lock);
1530 		if (!list_empty(&cmd->i_conn_node))
1531 			list_del_init(&cmd->i_conn_node);
1532 		spin_unlock_bh(&conn->cmd_lock);
1533 
1534 		transport_generic_free_cmd(&cmd->se_cmd, 0);
1535 		break;
1536 	case ISCSI_OP_REJECT:
1537 	case ISCSI_OP_NOOP_OUT:
1538 	case ISCSI_OP_TEXT:
1539 		hdr = (struct iscsi_text_rsp *)&isert_cmd->tx_desc.iscsi_header;
1540 		/* If the continue bit is on, keep the command alive */
1541 		if (hdr->flags & ISCSI_FLAG_TEXT_CONTINUE)
1542 			break;
1543 
1544 		spin_lock_bh(&conn->cmd_lock);
1545 		if (!list_empty(&cmd->i_conn_node))
1546 			list_del_init(&cmd->i_conn_node);
1547 		spin_unlock_bh(&conn->cmd_lock);
1548 
1549 		/*
1550 		 * Handle special case for REJECT when iscsi_add_reject*() has
1551 		 * overwritten the original iscsi_opcode assignment, and the
1552 		 * associated cmd->se_cmd needs to be released.
1553 		 */
1554 		if (cmd->se_cmd.se_tfo != NULL) {
1555 			isert_dbg("Calling transport_generic_free_cmd for 0x%02x\n",
1556 				 cmd->iscsi_opcode);
1557 			transport_generic_free_cmd(&cmd->se_cmd, 0);
1558 			break;
1559 		}
1560 		/*
1561 		 * Fall-through
1562 		 */
1563 	default:
1564 		iscsit_release_cmd(cmd);
1565 		break;
1566 	}
1567 }
1568 
1569 static void
1570 isert_unmap_tx_desc(struct iser_tx_desc *tx_desc, struct ib_device *ib_dev)
1571 {
1572 	if (tx_desc->dma_addr != 0) {
1573 		isert_dbg("unmap single for tx_desc->dma_addr\n");
1574 		ib_dma_unmap_single(ib_dev, tx_desc->dma_addr,
1575 				    ISER_HEADERS_LEN, DMA_TO_DEVICE);
1576 		tx_desc->dma_addr = 0;
1577 	}
1578 }
1579 
1580 static void
1581 isert_completion_put(struct iser_tx_desc *tx_desc, struct isert_cmd *isert_cmd,
1582 		     struct ib_device *ib_dev, bool comp_err)
1583 {
1584 	if (isert_cmd->pdu_buf_dma != 0) {
1585 		isert_dbg("unmap single for isert_cmd->pdu_buf_dma\n");
1586 		ib_dma_unmap_single(ib_dev, isert_cmd->pdu_buf_dma,
1587 				    isert_cmd->pdu_buf_len, DMA_TO_DEVICE);
1588 		isert_cmd->pdu_buf_dma = 0;
1589 	}
1590 
1591 	isert_unmap_tx_desc(tx_desc, ib_dev);
1592 	isert_put_cmd(isert_cmd, comp_err);
1593 }
1594 
1595 static int
1596 isert_check_pi_status(struct se_cmd *se_cmd, struct ib_mr *sig_mr)
1597 {
1598 	struct ib_mr_status mr_status;
1599 	int ret;
1600 
1601 	ret = ib_check_mr_status(sig_mr, IB_MR_CHECK_SIG_STATUS, &mr_status);
1602 	if (ret) {
1603 		isert_err("ib_check_mr_status failed, ret %d\n", ret);
1604 		goto fail_mr_status;
1605 	}
1606 
1607 	if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1608 		u64 sec_offset_err;
1609 		u32 block_size = se_cmd->se_dev->dev_attrib.block_size + 8;
1610 
1611 		switch (mr_status.sig_err.err_type) {
1612 		case IB_SIG_BAD_GUARD:
1613 			se_cmd->pi_err = TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1614 			break;
1615 		case IB_SIG_BAD_REFTAG:
1616 			se_cmd->pi_err = TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1617 			break;
1618 		case IB_SIG_BAD_APPTAG:
1619 			se_cmd->pi_err = TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED;
1620 			break;
1621 		}
1622 		sec_offset_err = mr_status.sig_err.sig_err_offset;
1623 		do_div(sec_offset_err, block_size);
1624 		se_cmd->bad_sector = sec_offset_err + se_cmd->t_task_lba;
1625 
1626 		isert_err("PI error found type %d at sector 0x%llx "
1627 			  "expected 0x%x vs actual 0x%x\n",
1628 			  mr_status.sig_err.err_type,
1629 			  (unsigned long long)se_cmd->bad_sector,
1630 			  mr_status.sig_err.expected,
1631 			  mr_status.sig_err.actual);
1632 		ret = 1;
1633 	}
1634 
1635 fail_mr_status:
1636 	return ret;
1637 }
1638 
1639 static void
1640 isert_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc)
1641 {
1642 	struct isert_conn *isert_conn = wc->qp->qp_context;
1643 	struct isert_device *device = isert_conn->device;
1644 	struct iser_tx_desc *desc = cqe_to_tx_desc(wc->wr_cqe);
1645 	struct isert_cmd *isert_cmd = tx_desc_to_cmd(desc);
1646 	struct se_cmd *cmd = &isert_cmd->iscsi_cmd->se_cmd;
1647 	int ret = 0;
1648 
1649 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
1650 		isert_print_wc(wc, "rdma write");
1651 		if (wc->status != IB_WC_WR_FLUSH_ERR)
1652 			iscsit_cause_connection_reinstatement(isert_conn->conn, 0);
1653 		isert_completion_put(desc, isert_cmd, device->ib_device, true);
1654 		return;
1655 	}
1656 
1657 	isert_dbg("Cmd %p\n", isert_cmd);
1658 
1659 	ret = isert_check_pi_status(cmd, isert_cmd->rw.sig->sig_mr);
1660 	isert_rdma_rw_ctx_destroy(isert_cmd, isert_conn);
1661 
1662 	if (ret)
1663 		transport_send_check_condition_and_sense(cmd, cmd->pi_err, 0);
1664 	else
1665 		isert_put_response(isert_conn->conn, isert_cmd->iscsi_cmd);
1666 }
1667 
1668 static void
1669 isert_rdma_read_done(struct ib_cq *cq, struct ib_wc *wc)
1670 {
1671 	struct isert_conn *isert_conn = wc->qp->qp_context;
1672 	struct isert_device *device = isert_conn->device;
1673 	struct iser_tx_desc *desc = cqe_to_tx_desc(wc->wr_cqe);
1674 	struct isert_cmd *isert_cmd = tx_desc_to_cmd(desc);
1675 	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
1676 	struct se_cmd *se_cmd = &cmd->se_cmd;
1677 	int ret = 0;
1678 
1679 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
1680 		isert_print_wc(wc, "rdma read");
1681 		if (wc->status != IB_WC_WR_FLUSH_ERR)
1682 			iscsit_cause_connection_reinstatement(isert_conn->conn, 0);
1683 		isert_completion_put(desc, isert_cmd, device->ib_device, true);
1684 		return;
1685 	}
1686 
1687 	isert_dbg("Cmd %p\n", isert_cmd);
1688 
1689 	iscsit_stop_dataout_timer(cmd);
1690 
1691 	if (isert_prot_cmd(isert_conn, se_cmd))
1692 		ret = isert_check_pi_status(se_cmd, isert_cmd->rw.sig->sig_mr);
1693 	isert_rdma_rw_ctx_destroy(isert_cmd, isert_conn);
1694 	cmd->write_data_done = 0;
1695 
1696 	isert_dbg("Cmd: %p RDMA_READ comp calling execute_cmd\n", isert_cmd);
1697 	spin_lock_bh(&cmd->istate_lock);
1698 	cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
1699 	cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
1700 	spin_unlock_bh(&cmd->istate_lock);
1701 
1702 	if (ret) {
1703 		target_put_sess_cmd(se_cmd);
1704 		transport_send_check_condition_and_sense(se_cmd,
1705 							 se_cmd->pi_err, 0);
1706 	} else {
1707 		target_execute_cmd(se_cmd);
1708 	}
1709 }
1710 
1711 static void
1712 isert_do_control_comp(struct work_struct *work)
1713 {
1714 	struct isert_cmd *isert_cmd = container_of(work,
1715 			struct isert_cmd, comp_work);
1716 	struct isert_conn *isert_conn = isert_cmd->conn;
1717 	struct ib_device *ib_dev = isert_conn->cm_id->device;
1718 	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
1719 
1720 	isert_dbg("Cmd %p i_state %d\n", isert_cmd, cmd->i_state);
1721 
1722 	switch (cmd->i_state) {
1723 	case ISTATE_SEND_TASKMGTRSP:
1724 		iscsit_tmr_post_handler(cmd, cmd->conn);
1725 	case ISTATE_SEND_REJECT:   /* FALLTHRU */
1726 	case ISTATE_SEND_TEXTRSP:  /* FALLTHRU */
1727 		cmd->i_state = ISTATE_SENT_STATUS;
1728 		isert_completion_put(&isert_cmd->tx_desc, isert_cmd,
1729 				     ib_dev, false);
1730 		break;
1731 	case ISTATE_SEND_LOGOUTRSP:
1732 		iscsit_logout_post_handler(cmd, cmd->conn);
1733 		break;
1734 	default:
1735 		isert_err("Unknown i_state %d\n", cmd->i_state);
1736 		dump_stack();
1737 		break;
1738 	}
1739 }
1740 
1741 static void
1742 isert_login_send_done(struct ib_cq *cq, struct ib_wc *wc)
1743 {
1744 	struct isert_conn *isert_conn = wc->qp->qp_context;
1745 	struct ib_device *ib_dev = isert_conn->cm_id->device;
1746 	struct iser_tx_desc *tx_desc = cqe_to_tx_desc(wc->wr_cqe);
1747 
1748 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
1749 		isert_print_wc(wc, "login send");
1750 		if (wc->status != IB_WC_WR_FLUSH_ERR)
1751 			iscsit_cause_connection_reinstatement(isert_conn->conn, 0);
1752 	}
1753 
1754 	isert_unmap_tx_desc(tx_desc, ib_dev);
1755 }
1756 
1757 static void
1758 isert_send_done(struct ib_cq *cq, struct ib_wc *wc)
1759 {
1760 	struct isert_conn *isert_conn = wc->qp->qp_context;
1761 	struct ib_device *ib_dev = isert_conn->cm_id->device;
1762 	struct iser_tx_desc *tx_desc = cqe_to_tx_desc(wc->wr_cqe);
1763 	struct isert_cmd *isert_cmd = tx_desc_to_cmd(tx_desc);
1764 
1765 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
1766 		isert_print_wc(wc, "send");
1767 		if (wc->status != IB_WC_WR_FLUSH_ERR)
1768 			iscsit_cause_connection_reinstatement(isert_conn->conn, 0);
1769 		isert_completion_put(tx_desc, isert_cmd, ib_dev, true);
1770 		return;
1771 	}
1772 
1773 	isert_dbg("Cmd %p\n", isert_cmd);
1774 
1775 	switch (isert_cmd->iscsi_cmd->i_state) {
1776 	case ISTATE_SEND_TASKMGTRSP:
1777 	case ISTATE_SEND_LOGOUTRSP:
1778 	case ISTATE_SEND_REJECT:
1779 	case ISTATE_SEND_TEXTRSP:
1780 		isert_unmap_tx_desc(tx_desc, ib_dev);
1781 
1782 		INIT_WORK(&isert_cmd->comp_work, isert_do_control_comp);
1783 		queue_work(isert_comp_wq, &isert_cmd->comp_work);
1784 		return;
1785 	default:
1786 		isert_cmd->iscsi_cmd->i_state = ISTATE_SENT_STATUS;
1787 		isert_completion_put(tx_desc, isert_cmd, ib_dev, false);
1788 		break;
1789 	}
1790 }
1791 
1792 static int
1793 isert_post_response(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd)
1794 {
1795 	struct ib_send_wr *wr_failed;
1796 	int ret;
1797 
1798 	ret = isert_post_recv(isert_conn, isert_cmd->rx_desc);
1799 	if (ret) {
1800 		isert_err("ib_post_recv failed with %d\n", ret);
1801 		return ret;
1802 	}
1803 
1804 	ret = ib_post_send(isert_conn->qp, &isert_cmd->tx_desc.send_wr,
1805 			   &wr_failed);
1806 	if (ret) {
1807 		isert_err("ib_post_send failed with %d\n", ret);
1808 		return ret;
1809 	}
1810 	return ret;
1811 }
1812 
1813 static int
1814 isert_put_response(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
1815 {
1816 	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
1817 	struct isert_conn *isert_conn = conn->context;
1818 	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
1819 	struct iscsi_scsi_rsp *hdr = (struct iscsi_scsi_rsp *)
1820 				&isert_cmd->tx_desc.iscsi_header;
1821 
1822 	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
1823 	iscsit_build_rsp_pdu(cmd, conn, true, hdr);
1824 	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
1825 	/*
1826 	 * Attach SENSE DATA payload to iSCSI Response PDU
1827 	 */
1828 	if (cmd->se_cmd.sense_buffer &&
1829 	    ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1830 	    (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
1831 		struct isert_device *device = isert_conn->device;
1832 		struct ib_device *ib_dev = device->ib_device;
1833 		struct ib_sge *tx_dsg = &isert_cmd->tx_desc.tx_sg[1];
1834 		u32 padding, pdu_len;
1835 
1836 		put_unaligned_be16(cmd->se_cmd.scsi_sense_length,
1837 				   cmd->sense_buffer);
1838 		cmd->se_cmd.scsi_sense_length += sizeof(__be16);
1839 
1840 		padding = -(cmd->se_cmd.scsi_sense_length) & 3;
1841 		hton24(hdr->dlength, (u32)cmd->se_cmd.scsi_sense_length);
1842 		pdu_len = cmd->se_cmd.scsi_sense_length + padding;
1843 
1844 		isert_cmd->pdu_buf_dma = ib_dma_map_single(ib_dev,
1845 				(void *)cmd->sense_buffer, pdu_len,
1846 				DMA_TO_DEVICE);
1847 		if (ib_dma_mapping_error(ib_dev, isert_cmd->pdu_buf_dma))
1848 			return -ENOMEM;
1849 
1850 		isert_cmd->pdu_buf_len = pdu_len;
1851 		tx_dsg->addr	= isert_cmd->pdu_buf_dma;
1852 		tx_dsg->length	= pdu_len;
1853 		tx_dsg->lkey	= device->pd->local_dma_lkey;
1854 		isert_cmd->tx_desc.num_sge = 2;
1855 	}
1856 
1857 	isert_init_send_wr(isert_conn, isert_cmd, send_wr);
1858 
1859 	isert_dbg("Posting SCSI Response\n");
1860 
1861 	return isert_post_response(isert_conn, isert_cmd);
1862 }
1863 
1864 static void
1865 isert_aborted_task(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
1866 {
1867 	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
1868 	struct isert_conn *isert_conn = conn->context;
1869 
1870 	spin_lock_bh(&conn->cmd_lock);
1871 	if (!list_empty(&cmd->i_conn_node))
1872 		list_del_init(&cmd->i_conn_node);
1873 	spin_unlock_bh(&conn->cmd_lock);
1874 
1875 	if (cmd->data_direction == DMA_TO_DEVICE)
1876 		iscsit_stop_dataout_timer(cmd);
1877 	isert_rdma_rw_ctx_destroy(isert_cmd, isert_conn);
1878 }
1879 
1880 static enum target_prot_op
1881 isert_get_sup_prot_ops(struct iscsi_conn *conn)
1882 {
1883 	struct isert_conn *isert_conn = conn->context;
1884 	struct isert_device *device = isert_conn->device;
1885 
1886 	if (conn->tpg->tpg_attrib.t10_pi) {
1887 		if (device->pi_capable) {
1888 			isert_info("conn %p PI offload enabled\n", isert_conn);
1889 			isert_conn->pi_support = true;
1890 			return TARGET_PROT_ALL;
1891 		}
1892 	}
1893 
1894 	isert_info("conn %p PI offload disabled\n", isert_conn);
1895 	isert_conn->pi_support = false;
1896 
1897 	return TARGET_PROT_NORMAL;
1898 }
1899 
1900 static int
1901 isert_put_nopin(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
1902 		bool nopout_response)
1903 {
1904 	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
1905 	struct isert_conn *isert_conn = conn->context;
1906 	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
1907 
1908 	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
1909 	iscsit_build_nopin_rsp(cmd, conn, (struct iscsi_nopin *)
1910 			       &isert_cmd->tx_desc.iscsi_header,
1911 			       nopout_response);
1912 	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
1913 	isert_init_send_wr(isert_conn, isert_cmd, send_wr);
1914 
1915 	isert_dbg("conn %p Posting NOPIN Response\n", isert_conn);
1916 
1917 	return isert_post_response(isert_conn, isert_cmd);
1918 }
1919 
1920 static int
1921 isert_put_logout_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
1922 {
1923 	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
1924 	struct isert_conn *isert_conn = conn->context;
1925 	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
1926 
1927 	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
1928 	iscsit_build_logout_rsp(cmd, conn, (struct iscsi_logout_rsp *)
1929 				&isert_cmd->tx_desc.iscsi_header);
1930 	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
1931 	isert_init_send_wr(isert_conn, isert_cmd, send_wr);
1932 
1933 	isert_dbg("conn %p Posting Logout Response\n", isert_conn);
1934 
1935 	return isert_post_response(isert_conn, isert_cmd);
1936 }
1937 
1938 static int
1939 isert_put_tm_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
1940 {
1941 	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
1942 	struct isert_conn *isert_conn = conn->context;
1943 	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
1944 
1945 	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
1946 	iscsit_build_task_mgt_rsp(cmd, conn, (struct iscsi_tm_rsp *)
1947 				  &isert_cmd->tx_desc.iscsi_header);
1948 	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
1949 	isert_init_send_wr(isert_conn, isert_cmd, send_wr);
1950 
1951 	isert_dbg("conn %p Posting Task Management Response\n", isert_conn);
1952 
1953 	return isert_post_response(isert_conn, isert_cmd);
1954 }
1955 
1956 static int
1957 isert_put_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
1958 {
1959 	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
1960 	struct isert_conn *isert_conn = conn->context;
1961 	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
1962 	struct isert_device *device = isert_conn->device;
1963 	struct ib_device *ib_dev = device->ib_device;
1964 	struct ib_sge *tx_dsg = &isert_cmd->tx_desc.tx_sg[1];
1965 	struct iscsi_reject *hdr =
1966 		(struct iscsi_reject *)&isert_cmd->tx_desc.iscsi_header;
1967 
1968 	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
1969 	iscsit_build_reject(cmd, conn, hdr);
1970 	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
1971 
1972 	hton24(hdr->dlength, ISCSI_HDR_LEN);
1973 	isert_cmd->pdu_buf_dma = ib_dma_map_single(ib_dev,
1974 			(void *)cmd->buf_ptr, ISCSI_HDR_LEN,
1975 			DMA_TO_DEVICE);
1976 	if (ib_dma_mapping_error(ib_dev, isert_cmd->pdu_buf_dma))
1977 		return -ENOMEM;
1978 	isert_cmd->pdu_buf_len = ISCSI_HDR_LEN;
1979 	tx_dsg->addr	= isert_cmd->pdu_buf_dma;
1980 	tx_dsg->length	= ISCSI_HDR_LEN;
1981 	tx_dsg->lkey	= device->pd->local_dma_lkey;
1982 	isert_cmd->tx_desc.num_sge = 2;
1983 
1984 	isert_init_send_wr(isert_conn, isert_cmd, send_wr);
1985 
1986 	isert_dbg("conn %p Posting Reject\n", isert_conn);
1987 
1988 	return isert_post_response(isert_conn, isert_cmd);
1989 }
1990 
1991 static int
1992 isert_put_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
1993 {
1994 	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
1995 	struct isert_conn *isert_conn = conn->context;
1996 	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
1997 	struct iscsi_text_rsp *hdr =
1998 		(struct iscsi_text_rsp *)&isert_cmd->tx_desc.iscsi_header;
1999 	u32 txt_rsp_len;
2000 	int rc;
2001 
2002 	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
2003 	rc = iscsit_build_text_rsp(cmd, conn, hdr, ISCSI_INFINIBAND);
2004 	if (rc < 0)
2005 		return rc;
2006 
2007 	txt_rsp_len = rc;
2008 	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
2009 
2010 	if (txt_rsp_len) {
2011 		struct isert_device *device = isert_conn->device;
2012 		struct ib_device *ib_dev = device->ib_device;
2013 		struct ib_sge *tx_dsg = &isert_cmd->tx_desc.tx_sg[1];
2014 		void *txt_rsp_buf = cmd->buf_ptr;
2015 
2016 		isert_cmd->pdu_buf_dma = ib_dma_map_single(ib_dev,
2017 				txt_rsp_buf, txt_rsp_len, DMA_TO_DEVICE);
2018 		if (ib_dma_mapping_error(ib_dev, isert_cmd->pdu_buf_dma))
2019 			return -ENOMEM;
2020 
2021 		isert_cmd->pdu_buf_len = txt_rsp_len;
2022 		tx_dsg->addr	= isert_cmd->pdu_buf_dma;
2023 		tx_dsg->length	= txt_rsp_len;
2024 		tx_dsg->lkey	= device->pd->local_dma_lkey;
2025 		isert_cmd->tx_desc.num_sge = 2;
2026 	}
2027 	isert_init_send_wr(isert_conn, isert_cmd, send_wr);
2028 
2029 	isert_dbg("conn %p Text Response\n", isert_conn);
2030 
2031 	return isert_post_response(isert_conn, isert_cmd);
2032 }
2033 
2034 static inline void
2035 isert_set_dif_domain(struct se_cmd *se_cmd, struct ib_sig_attrs *sig_attrs,
2036 		     struct ib_sig_domain *domain)
2037 {
2038 	domain->sig_type = IB_SIG_TYPE_T10_DIF;
2039 	domain->sig.dif.bg_type = IB_T10DIF_CRC;
2040 	domain->sig.dif.pi_interval = se_cmd->se_dev->dev_attrib.block_size;
2041 	domain->sig.dif.ref_tag = se_cmd->reftag_seed;
2042 	/*
2043 	 * At the moment we hard code those, but if in the future
2044 	 * the target core would like to use it, we will take it
2045 	 * from se_cmd.
2046 	 */
2047 	domain->sig.dif.apptag_check_mask = 0xffff;
2048 	domain->sig.dif.app_escape = true;
2049 	domain->sig.dif.ref_escape = true;
2050 	if (se_cmd->prot_type == TARGET_DIF_TYPE1_PROT ||
2051 	    se_cmd->prot_type == TARGET_DIF_TYPE2_PROT)
2052 		domain->sig.dif.ref_remap = true;
2053 };
2054 
2055 static int
2056 isert_set_sig_attrs(struct se_cmd *se_cmd, struct ib_sig_attrs *sig_attrs)
2057 {
2058 	memset(sig_attrs, 0, sizeof(*sig_attrs));
2059 
2060 	switch (se_cmd->prot_op) {
2061 	case TARGET_PROT_DIN_INSERT:
2062 	case TARGET_PROT_DOUT_STRIP:
2063 		sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
2064 		isert_set_dif_domain(se_cmd, sig_attrs, &sig_attrs->wire);
2065 		break;
2066 	case TARGET_PROT_DOUT_INSERT:
2067 	case TARGET_PROT_DIN_STRIP:
2068 		sig_attrs->wire.sig_type = IB_SIG_TYPE_NONE;
2069 		isert_set_dif_domain(se_cmd, sig_attrs, &sig_attrs->mem);
2070 		break;
2071 	case TARGET_PROT_DIN_PASS:
2072 	case TARGET_PROT_DOUT_PASS:
2073 		isert_set_dif_domain(se_cmd, sig_attrs, &sig_attrs->wire);
2074 		isert_set_dif_domain(se_cmd, sig_attrs, &sig_attrs->mem);
2075 		break;
2076 	default:
2077 		isert_err("Unsupported PI operation %d\n", se_cmd->prot_op);
2078 		return -EINVAL;
2079 	}
2080 
2081 	sig_attrs->check_mask =
2082 	       (se_cmd->prot_checks & TARGET_DIF_CHECK_GUARD  ? 0xc0 : 0) |
2083 	       (se_cmd->prot_checks & TARGET_DIF_CHECK_REFTAG ? 0x30 : 0) |
2084 	       (se_cmd->prot_checks & TARGET_DIF_CHECK_REFTAG ? 0x0f : 0);
2085 	return 0;
2086 }
2087 
2088 static int
2089 isert_rdma_rw_ctx_post(struct isert_cmd *cmd, struct isert_conn *conn,
2090 		struct ib_cqe *cqe, struct ib_send_wr *chain_wr)
2091 {
2092 	struct se_cmd *se_cmd = &cmd->iscsi_cmd->se_cmd;
2093 	enum dma_data_direction dir = target_reverse_dma_direction(se_cmd);
2094 	u8 port_num = conn->cm_id->port_num;
2095 	u64 addr;
2096 	u32 rkey, offset;
2097 	int ret;
2098 
2099 	if (dir == DMA_FROM_DEVICE) {
2100 		addr = cmd->write_va;
2101 		rkey = cmd->write_stag;
2102 		offset = cmd->iscsi_cmd->write_data_done;
2103 	} else {
2104 		addr = cmd->read_va;
2105 		rkey = cmd->read_stag;
2106 		offset = 0;
2107 	}
2108 
2109 	if (isert_prot_cmd(conn, se_cmd)) {
2110 		struct ib_sig_attrs sig_attrs;
2111 
2112 		ret = isert_set_sig_attrs(se_cmd, &sig_attrs);
2113 		if (ret)
2114 			return ret;
2115 
2116 		WARN_ON_ONCE(offset);
2117 		ret = rdma_rw_ctx_signature_init(&cmd->rw, conn->qp, port_num,
2118 				se_cmd->t_data_sg, se_cmd->t_data_nents,
2119 				se_cmd->t_prot_sg, se_cmd->t_prot_nents,
2120 				&sig_attrs, addr, rkey, dir);
2121 	} else {
2122 		ret = rdma_rw_ctx_init(&cmd->rw, conn->qp, port_num,
2123 				se_cmd->t_data_sg, se_cmd->t_data_nents,
2124 				offset, addr, rkey, dir);
2125 	}
2126 	if (ret < 0) {
2127 		isert_err("Cmd: %p failed to prepare RDMA res\n", cmd);
2128 		return ret;
2129 	}
2130 
2131 	ret = rdma_rw_ctx_post(&cmd->rw, conn->qp, port_num, cqe, chain_wr);
2132 	if (ret < 0)
2133 		isert_err("Cmd: %p failed to post RDMA res\n", cmd);
2134 	return ret;
2135 }
2136 
2137 static int
2138 isert_put_datain(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
2139 {
2140 	struct se_cmd *se_cmd = &cmd->se_cmd;
2141 	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
2142 	struct isert_conn *isert_conn = conn->context;
2143 	struct ib_cqe *cqe = NULL;
2144 	struct ib_send_wr *chain_wr = NULL;
2145 	int rc;
2146 
2147 	isert_dbg("Cmd: %p RDMA_WRITE data_length: %u\n",
2148 		 isert_cmd, se_cmd->data_length);
2149 
2150 	if (isert_prot_cmd(isert_conn, se_cmd)) {
2151 		isert_cmd->tx_desc.tx_cqe.done = isert_rdma_write_done;
2152 		cqe = &isert_cmd->tx_desc.tx_cqe;
2153 	} else {
2154 		/*
2155 		 * Build isert_conn->tx_desc for iSCSI response PDU and attach
2156 		 */
2157 		isert_create_send_desc(isert_conn, isert_cmd,
2158 				       &isert_cmd->tx_desc);
2159 		iscsit_build_rsp_pdu(cmd, conn, true, (struct iscsi_scsi_rsp *)
2160 				     &isert_cmd->tx_desc.iscsi_header);
2161 		isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
2162 		isert_init_send_wr(isert_conn, isert_cmd,
2163 				   &isert_cmd->tx_desc.send_wr);
2164 
2165 		rc = isert_post_recv(isert_conn, isert_cmd->rx_desc);
2166 		if (rc) {
2167 			isert_err("ib_post_recv failed with %d\n", rc);
2168 			return rc;
2169 		}
2170 
2171 		chain_wr = &isert_cmd->tx_desc.send_wr;
2172 	}
2173 
2174 	isert_rdma_rw_ctx_post(isert_cmd, isert_conn, cqe, chain_wr);
2175 	isert_dbg("Cmd: %p posted RDMA_WRITE for iSER Data READ\n", isert_cmd);
2176 	return 1;
2177 }
2178 
2179 static int
2180 isert_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd, bool recovery)
2181 {
2182 	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
2183 
2184 	isert_dbg("Cmd: %p RDMA_READ data_length: %u write_data_done: %u\n",
2185 		 isert_cmd, cmd->se_cmd.data_length, cmd->write_data_done);
2186 
2187 	isert_cmd->tx_desc.tx_cqe.done = isert_rdma_read_done;
2188 	isert_rdma_rw_ctx_post(isert_cmd, conn->context,
2189 			&isert_cmd->tx_desc.tx_cqe, NULL);
2190 
2191 	isert_dbg("Cmd: %p posted RDMA_READ memory for ISER Data WRITE\n",
2192 		 isert_cmd);
2193 	return 0;
2194 }
2195 
2196 static int
2197 isert_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
2198 {
2199 	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
2200 	int ret = 0;
2201 
2202 	switch (state) {
2203 	case ISTATE_REMOVE:
2204 		spin_lock_bh(&conn->cmd_lock);
2205 		list_del_init(&cmd->i_conn_node);
2206 		spin_unlock_bh(&conn->cmd_lock);
2207 		isert_put_cmd(isert_cmd, true);
2208 		break;
2209 	case ISTATE_SEND_NOPIN_WANT_RESPONSE:
2210 		ret = isert_put_nopin(cmd, conn, false);
2211 		break;
2212 	default:
2213 		isert_err("Unknown immediate state: 0x%02x\n", state);
2214 		ret = -EINVAL;
2215 		break;
2216 	}
2217 
2218 	return ret;
2219 }
2220 
2221 static int
2222 isert_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
2223 {
2224 	struct isert_conn *isert_conn = conn->context;
2225 	int ret;
2226 
2227 	switch (state) {
2228 	case ISTATE_SEND_LOGOUTRSP:
2229 		ret = isert_put_logout_rsp(cmd, conn);
2230 		if (!ret)
2231 			isert_conn->logout_posted = true;
2232 		break;
2233 	case ISTATE_SEND_NOPIN:
2234 		ret = isert_put_nopin(cmd, conn, true);
2235 		break;
2236 	case ISTATE_SEND_TASKMGTRSP:
2237 		ret = isert_put_tm_rsp(cmd, conn);
2238 		break;
2239 	case ISTATE_SEND_REJECT:
2240 		ret = isert_put_reject(cmd, conn);
2241 		break;
2242 	case ISTATE_SEND_TEXTRSP:
2243 		ret = isert_put_text_rsp(cmd, conn);
2244 		break;
2245 	case ISTATE_SEND_STATUS:
2246 		/*
2247 		 * Special case for sending non GOOD SCSI status from TX thread
2248 		 * context during pre se_cmd excecution failure.
2249 		 */
2250 		ret = isert_put_response(conn, cmd);
2251 		break;
2252 	default:
2253 		isert_err("Unknown response state: 0x%02x\n", state);
2254 		ret = -EINVAL;
2255 		break;
2256 	}
2257 
2258 	return ret;
2259 }
2260 
2261 struct rdma_cm_id *
2262 isert_setup_id(struct isert_np *isert_np)
2263 {
2264 	struct iscsi_np *np = isert_np->np;
2265 	struct rdma_cm_id *id;
2266 	struct sockaddr *sa;
2267 	int ret;
2268 
2269 	sa = (struct sockaddr *)&np->np_sockaddr;
2270 	isert_dbg("ksockaddr: %p, sa: %p\n", &np->np_sockaddr, sa);
2271 
2272 	id = rdma_create_id(&init_net, isert_cma_handler, isert_np,
2273 			    RDMA_PS_TCP, IB_QPT_RC);
2274 	if (IS_ERR(id)) {
2275 		isert_err("rdma_create_id() failed: %ld\n", PTR_ERR(id));
2276 		ret = PTR_ERR(id);
2277 		goto out;
2278 	}
2279 	isert_dbg("id %p context %p\n", id, id->context);
2280 
2281 	ret = rdma_bind_addr(id, sa);
2282 	if (ret) {
2283 		isert_err("rdma_bind_addr() failed: %d\n", ret);
2284 		goto out_id;
2285 	}
2286 
2287 	ret = rdma_listen(id, 0);
2288 	if (ret) {
2289 		isert_err("rdma_listen() failed: %d\n", ret);
2290 		goto out_id;
2291 	}
2292 
2293 	return id;
2294 out_id:
2295 	rdma_destroy_id(id);
2296 out:
2297 	return ERR_PTR(ret);
2298 }
2299 
2300 static int
2301 isert_setup_np(struct iscsi_np *np,
2302 	       struct sockaddr_storage *ksockaddr)
2303 {
2304 	struct isert_np *isert_np;
2305 	struct rdma_cm_id *isert_lid;
2306 	int ret;
2307 
2308 	isert_np = kzalloc(sizeof(struct isert_np), GFP_KERNEL);
2309 	if (!isert_np)
2310 		return -ENOMEM;
2311 
2312 	sema_init(&isert_np->sem, 0);
2313 	mutex_init(&isert_np->mutex);
2314 	INIT_LIST_HEAD(&isert_np->accepted);
2315 	INIT_LIST_HEAD(&isert_np->pending);
2316 	isert_np->np = np;
2317 
2318 	/*
2319 	 * Setup the np->np_sockaddr from the passed sockaddr setup
2320 	 * in iscsi_target_configfs.c code..
2321 	 */
2322 	memcpy(&np->np_sockaddr, ksockaddr,
2323 	       sizeof(struct sockaddr_storage));
2324 
2325 	isert_lid = isert_setup_id(isert_np);
2326 	if (IS_ERR(isert_lid)) {
2327 		ret = PTR_ERR(isert_lid);
2328 		goto out;
2329 	}
2330 
2331 	isert_np->cm_id = isert_lid;
2332 	np->np_context = isert_np;
2333 
2334 	return 0;
2335 
2336 out:
2337 	kfree(isert_np);
2338 
2339 	return ret;
2340 }
2341 
2342 static int
2343 isert_rdma_accept(struct isert_conn *isert_conn)
2344 {
2345 	struct rdma_cm_id *cm_id = isert_conn->cm_id;
2346 	struct rdma_conn_param cp;
2347 	int ret;
2348 	struct iser_cm_hdr rsp_hdr;
2349 
2350 	memset(&cp, 0, sizeof(struct rdma_conn_param));
2351 	cp.initiator_depth = isert_conn->initiator_depth;
2352 	cp.retry_count = 7;
2353 	cp.rnr_retry_count = 7;
2354 
2355 	memset(&rsp_hdr, 0, sizeof(rsp_hdr));
2356 	rsp_hdr.flags = ISERT_ZBVA_NOT_USED;
2357 	if (!isert_conn->snd_w_inv)
2358 		rsp_hdr.flags = rsp_hdr.flags | ISERT_SEND_W_INV_NOT_USED;
2359 	cp.private_data = (void *)&rsp_hdr;
2360 	cp.private_data_len = sizeof(rsp_hdr);
2361 
2362 	ret = rdma_accept(cm_id, &cp);
2363 	if (ret) {
2364 		isert_err("rdma_accept() failed with: %d\n", ret);
2365 		return ret;
2366 	}
2367 
2368 	return 0;
2369 }
2370 
2371 static int
2372 isert_get_login_rx(struct iscsi_conn *conn, struct iscsi_login *login)
2373 {
2374 	struct isert_conn *isert_conn = conn->context;
2375 	int ret;
2376 
2377 	isert_info("before login_req comp conn: %p\n", isert_conn);
2378 	ret = wait_for_completion_interruptible(&isert_conn->login_req_comp);
2379 	if (ret) {
2380 		isert_err("isert_conn %p interrupted before got login req\n",
2381 			  isert_conn);
2382 		return ret;
2383 	}
2384 	reinit_completion(&isert_conn->login_req_comp);
2385 
2386 	/*
2387 	 * For login requests after the first PDU, isert_rx_login_req() will
2388 	 * kick schedule_delayed_work(&conn->login_work) as the packet is
2389 	 * received, which turns this callback from iscsi_target_do_login_rx()
2390 	 * into a NOP.
2391 	 */
2392 	if (!login->first_request)
2393 		return 0;
2394 
2395 	isert_rx_login_req(isert_conn);
2396 
2397 	isert_info("before login_comp conn: %p\n", conn);
2398 	ret = wait_for_completion_interruptible(&isert_conn->login_comp);
2399 	if (ret)
2400 		return ret;
2401 
2402 	isert_info("processing login->req: %p\n", login->req);
2403 
2404 	return 0;
2405 }
2406 
2407 static void
2408 isert_set_conn_info(struct iscsi_np *np, struct iscsi_conn *conn,
2409 		    struct isert_conn *isert_conn)
2410 {
2411 	struct rdma_cm_id *cm_id = isert_conn->cm_id;
2412 	struct rdma_route *cm_route = &cm_id->route;
2413 
2414 	conn->login_family = np->np_sockaddr.ss_family;
2415 
2416 	conn->login_sockaddr = cm_route->addr.dst_addr;
2417 	conn->local_sockaddr = cm_route->addr.src_addr;
2418 }
2419 
2420 static int
2421 isert_accept_np(struct iscsi_np *np, struct iscsi_conn *conn)
2422 {
2423 	struct isert_np *isert_np = np->np_context;
2424 	struct isert_conn *isert_conn;
2425 	int ret;
2426 
2427 accept_wait:
2428 	ret = down_interruptible(&isert_np->sem);
2429 	if (ret)
2430 		return -ENODEV;
2431 
2432 	spin_lock_bh(&np->np_thread_lock);
2433 	if (np->np_thread_state >= ISCSI_NP_THREAD_RESET) {
2434 		spin_unlock_bh(&np->np_thread_lock);
2435 		isert_dbg("np_thread_state %d\n",
2436 			 np->np_thread_state);
2437 		/**
2438 		 * No point in stalling here when np_thread
2439 		 * is in state RESET/SHUTDOWN/EXIT - bail
2440 		 **/
2441 		return -ENODEV;
2442 	}
2443 	spin_unlock_bh(&np->np_thread_lock);
2444 
2445 	mutex_lock(&isert_np->mutex);
2446 	if (list_empty(&isert_np->pending)) {
2447 		mutex_unlock(&isert_np->mutex);
2448 		goto accept_wait;
2449 	}
2450 	isert_conn = list_first_entry(&isert_np->pending,
2451 			struct isert_conn, node);
2452 	list_del_init(&isert_conn->node);
2453 	mutex_unlock(&isert_np->mutex);
2454 
2455 	conn->context = isert_conn;
2456 	isert_conn->conn = conn;
2457 	isert_conn->state = ISER_CONN_BOUND;
2458 
2459 	isert_set_conn_info(np, conn, isert_conn);
2460 
2461 	isert_dbg("Processing isert_conn: %p\n", isert_conn);
2462 
2463 	return 0;
2464 }
2465 
2466 static void
2467 isert_free_np(struct iscsi_np *np)
2468 {
2469 	struct isert_np *isert_np = np->np_context;
2470 	struct isert_conn *isert_conn, *n;
2471 
2472 	if (isert_np->cm_id)
2473 		rdma_destroy_id(isert_np->cm_id);
2474 
2475 	/*
2476 	 * FIXME: At this point we don't have a good way to insure
2477 	 * that at this point we don't have hanging connections that
2478 	 * completed RDMA establishment but didn't start iscsi login
2479 	 * process. So work-around this by cleaning up what ever piled
2480 	 * up in accepted and pending lists.
2481 	 */
2482 	mutex_lock(&isert_np->mutex);
2483 	if (!list_empty(&isert_np->pending)) {
2484 		isert_info("Still have isert pending connections\n");
2485 		list_for_each_entry_safe(isert_conn, n,
2486 					 &isert_np->pending,
2487 					 node) {
2488 			isert_info("cleaning isert_conn %p state (%d)\n",
2489 				   isert_conn, isert_conn->state);
2490 			isert_connect_release(isert_conn);
2491 		}
2492 	}
2493 
2494 	if (!list_empty(&isert_np->accepted)) {
2495 		isert_info("Still have isert accepted connections\n");
2496 		list_for_each_entry_safe(isert_conn, n,
2497 					 &isert_np->accepted,
2498 					 node) {
2499 			isert_info("cleaning isert_conn %p state (%d)\n",
2500 				   isert_conn, isert_conn->state);
2501 			isert_connect_release(isert_conn);
2502 		}
2503 	}
2504 	mutex_unlock(&isert_np->mutex);
2505 
2506 	np->np_context = NULL;
2507 	kfree(isert_np);
2508 }
2509 
2510 static void isert_release_work(struct work_struct *work)
2511 {
2512 	struct isert_conn *isert_conn = container_of(work,
2513 						     struct isert_conn,
2514 						     release_work);
2515 
2516 	isert_info("Starting release conn %p\n", isert_conn);
2517 
2518 	mutex_lock(&isert_conn->mutex);
2519 	isert_conn->state = ISER_CONN_DOWN;
2520 	mutex_unlock(&isert_conn->mutex);
2521 
2522 	isert_info("Destroying conn %p\n", isert_conn);
2523 	isert_put_conn(isert_conn);
2524 }
2525 
2526 static void
2527 isert_wait4logout(struct isert_conn *isert_conn)
2528 {
2529 	struct iscsi_conn *conn = isert_conn->conn;
2530 
2531 	isert_info("conn %p\n", isert_conn);
2532 
2533 	if (isert_conn->logout_posted) {
2534 		isert_info("conn %p wait for conn_logout_comp\n", isert_conn);
2535 		wait_for_completion_timeout(&conn->conn_logout_comp,
2536 					    SECONDS_FOR_LOGOUT_COMP * HZ);
2537 	}
2538 }
2539 
2540 static void
2541 isert_wait4cmds(struct iscsi_conn *conn)
2542 {
2543 	isert_info("iscsi_conn %p\n", conn);
2544 
2545 	if (conn->sess) {
2546 		target_sess_cmd_list_set_waiting(conn->sess->se_sess);
2547 		target_wait_for_sess_cmds(conn->sess->se_sess);
2548 	}
2549 }
2550 
2551 /**
2552  * isert_put_unsol_pending_cmds() - Drop commands waiting for
2553  *     unsolicitate dataout
2554  * @conn:    iscsi connection
2555  *
2556  * We might still have commands that are waiting for unsolicited
2557  * dataouts messages. We must put the extra reference on those
2558  * before blocking on the target_wait_for_session_cmds
2559  */
2560 static void
2561 isert_put_unsol_pending_cmds(struct iscsi_conn *conn)
2562 {
2563 	struct iscsi_cmd *cmd, *tmp;
2564 	static LIST_HEAD(drop_cmd_list);
2565 
2566 	spin_lock_bh(&conn->cmd_lock);
2567 	list_for_each_entry_safe(cmd, tmp, &conn->conn_cmd_list, i_conn_node) {
2568 		if ((cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA) &&
2569 		    (cmd->write_data_done < conn->sess->sess_ops->FirstBurstLength) &&
2570 		    (cmd->write_data_done < cmd->se_cmd.data_length))
2571 			list_move_tail(&cmd->i_conn_node, &drop_cmd_list);
2572 	}
2573 	spin_unlock_bh(&conn->cmd_lock);
2574 
2575 	list_for_each_entry_safe(cmd, tmp, &drop_cmd_list, i_conn_node) {
2576 		list_del_init(&cmd->i_conn_node);
2577 		if (cmd->i_state != ISTATE_REMOVE) {
2578 			struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
2579 
2580 			isert_info("conn %p dropping cmd %p\n", conn, cmd);
2581 			isert_put_cmd(isert_cmd, true);
2582 		}
2583 	}
2584 }
2585 
2586 static void isert_wait_conn(struct iscsi_conn *conn)
2587 {
2588 	struct isert_conn *isert_conn = conn->context;
2589 
2590 	isert_info("Starting conn %p\n", isert_conn);
2591 
2592 	mutex_lock(&isert_conn->mutex);
2593 	isert_conn_terminate(isert_conn);
2594 	mutex_unlock(&isert_conn->mutex);
2595 
2596 	ib_drain_qp(isert_conn->qp);
2597 	isert_put_unsol_pending_cmds(conn);
2598 	isert_wait4cmds(conn);
2599 	isert_wait4logout(isert_conn);
2600 
2601 	queue_work(isert_release_wq, &isert_conn->release_work);
2602 }
2603 
2604 static void isert_free_conn(struct iscsi_conn *conn)
2605 {
2606 	struct isert_conn *isert_conn = conn->context;
2607 
2608 	ib_drain_qp(isert_conn->qp);
2609 	isert_put_conn(isert_conn);
2610 }
2611 
2612 static void isert_get_rx_pdu(struct iscsi_conn *conn)
2613 {
2614 	struct completion comp;
2615 
2616 	init_completion(&comp);
2617 
2618 	wait_for_completion_interruptible(&comp);
2619 }
2620 
2621 static struct iscsit_transport iser_target_transport = {
2622 	.name			= "IB/iSER",
2623 	.transport_type		= ISCSI_INFINIBAND,
2624 	.rdma_shutdown		= true,
2625 	.priv_size		= sizeof(struct isert_cmd),
2626 	.owner			= THIS_MODULE,
2627 	.iscsit_setup_np	= isert_setup_np,
2628 	.iscsit_accept_np	= isert_accept_np,
2629 	.iscsit_free_np		= isert_free_np,
2630 	.iscsit_wait_conn	= isert_wait_conn,
2631 	.iscsit_free_conn	= isert_free_conn,
2632 	.iscsit_get_login_rx	= isert_get_login_rx,
2633 	.iscsit_put_login_tx	= isert_put_login_tx,
2634 	.iscsit_immediate_queue	= isert_immediate_queue,
2635 	.iscsit_response_queue	= isert_response_queue,
2636 	.iscsit_get_dataout	= isert_get_dataout,
2637 	.iscsit_queue_data_in	= isert_put_datain,
2638 	.iscsit_queue_status	= isert_put_response,
2639 	.iscsit_aborted_task	= isert_aborted_task,
2640 	.iscsit_get_rx_pdu	= isert_get_rx_pdu,
2641 	.iscsit_get_sup_prot_ops = isert_get_sup_prot_ops,
2642 };
2643 
2644 static int __init isert_init(void)
2645 {
2646 	int ret;
2647 
2648 	isert_comp_wq = alloc_workqueue("isert_comp_wq",
2649 					WQ_UNBOUND | WQ_HIGHPRI, 0);
2650 	if (!isert_comp_wq) {
2651 		isert_err("Unable to allocate isert_comp_wq\n");
2652 		return -ENOMEM;
2653 	}
2654 
2655 	isert_release_wq = alloc_workqueue("isert_release_wq", WQ_UNBOUND,
2656 					WQ_UNBOUND_MAX_ACTIVE);
2657 	if (!isert_release_wq) {
2658 		isert_err("Unable to allocate isert_release_wq\n");
2659 		ret = -ENOMEM;
2660 		goto destroy_comp_wq;
2661 	}
2662 
2663 	iscsit_register_transport(&iser_target_transport);
2664 	isert_info("iSER_TARGET[0] - Loaded iser_target_transport\n");
2665 
2666 	return 0;
2667 
2668 destroy_comp_wq:
2669 	destroy_workqueue(isert_comp_wq);
2670 
2671 	return ret;
2672 }
2673 
2674 static void __exit isert_exit(void)
2675 {
2676 	flush_scheduled_work();
2677 	destroy_workqueue(isert_release_wq);
2678 	destroy_workqueue(isert_comp_wq);
2679 	iscsit_unregister_transport(&iser_target_transport);
2680 	isert_info("iSER_TARGET[0] - Released iser_target_transport\n");
2681 }
2682 
2683 MODULE_DESCRIPTION("iSER-Target for mainline target infrastructure");
2684 MODULE_VERSION("1.0");
2685 MODULE_AUTHOR("nab@Linux-iSCSI.org");
2686 MODULE_LICENSE("GPL");
2687 
2688 module_init(isert_init);
2689 module_exit(isert_exit);
2690