1 /*
2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
3  * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
4  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *	- Redistributions of source code must retain the above
17  *	  copyright notice, this list of conditions and the following
18  *	  disclaimer.
19  *
20  *	- Redistributions in binary form must reproduce the above
21  *	  copyright notice, this list of conditions and the following
22  *	  disclaimer in the documentation and/or other materials
23  *	  provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  */
34 #include <linux/kernel.h>
35 #include <linux/module.h>
36 #include <linux/slab.h>
37 #include <linux/delay.h>
38 
39 #include "iscsi_iser.h"
40 
41 #define ISCSI_ISER_MAX_CONN	8
42 #define ISER_MAX_RX_LEN		(ISER_QP_MAX_RECV_DTOS * ISCSI_ISER_MAX_CONN)
43 #define ISER_MAX_TX_LEN		(ISER_QP_MAX_REQ_DTOS  * ISCSI_ISER_MAX_CONN)
44 #define ISER_MAX_CQ_LEN		(ISER_MAX_RX_LEN + ISER_MAX_TX_LEN + \
45 				 ISCSI_ISER_MAX_CONN)
46 
47 static void iser_qp_event_callback(struct ib_event *cause, void *context)
48 {
49 	iser_err("qp event %s (%d)\n",
50 		 ib_event_msg(cause->event), cause->event);
51 }
52 
53 static void iser_event_handler(struct ib_event_handler *handler,
54 				struct ib_event *event)
55 {
56 	iser_err("async event %s (%d) on device %s port %d\n",
57 		 ib_event_msg(event->event), event->event,
58 		dev_name(&event->device->dev), event->element.port_num);
59 }
60 
61 /**
62  * iser_create_device_ib_res - creates Protection Domain (PD), Completion
63  * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
64  * the adapator.
65  *
66  * returns 0 on success, -1 on failure
67  */
68 static int iser_create_device_ib_res(struct iser_device *device)
69 {
70 	struct ib_device *ib_dev = device->ib_device;
71 	int ret, i, max_cqe;
72 
73 	ret = iser_assign_reg_ops(device);
74 	if (ret)
75 		return ret;
76 
77 	device->comps_used = min_t(int, num_online_cpus(),
78 				 ib_dev->num_comp_vectors);
79 
80 	device->comps = kcalloc(device->comps_used, sizeof(*device->comps),
81 				GFP_KERNEL);
82 	if (!device->comps)
83 		goto comps_err;
84 
85 	max_cqe = min(ISER_MAX_CQ_LEN, ib_dev->attrs.max_cqe);
86 
87 	iser_info("using %d CQs, device %s supports %d vectors max_cqe %d\n",
88 		  device->comps_used, dev_name(&ib_dev->dev),
89 		  ib_dev->num_comp_vectors, max_cqe);
90 
91 	device->pd = ib_alloc_pd(ib_dev,
92 		iser_always_reg ? 0 : IB_PD_UNSAFE_GLOBAL_RKEY);
93 	if (IS_ERR(device->pd))
94 		goto pd_err;
95 
96 	for (i = 0; i < device->comps_used; i++) {
97 		struct iser_comp *comp = &device->comps[i];
98 
99 		comp->cq = ib_alloc_cq(ib_dev, comp, max_cqe, i,
100 				       IB_POLL_SOFTIRQ);
101 		if (IS_ERR(comp->cq)) {
102 			comp->cq = NULL;
103 			goto cq_err;
104 		}
105 	}
106 
107 	INIT_IB_EVENT_HANDLER(&device->event_handler, ib_dev,
108 			      iser_event_handler);
109 	ib_register_event_handler(&device->event_handler);
110 	return 0;
111 
112 cq_err:
113 	for (i = 0; i < device->comps_used; i++) {
114 		struct iser_comp *comp = &device->comps[i];
115 
116 		if (comp->cq)
117 			ib_free_cq(comp->cq);
118 	}
119 	ib_dealloc_pd(device->pd);
120 pd_err:
121 	kfree(device->comps);
122 comps_err:
123 	iser_err("failed to allocate an IB resource\n");
124 	return -1;
125 }
126 
127 /**
128  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
129  * CQ and PD created with the device associated with the adapator.
130  */
131 static void iser_free_device_ib_res(struct iser_device *device)
132 {
133 	int i;
134 
135 	for (i = 0; i < device->comps_used; i++) {
136 		struct iser_comp *comp = &device->comps[i];
137 
138 		ib_free_cq(comp->cq);
139 		comp->cq = NULL;
140 	}
141 
142 	ib_unregister_event_handler(&device->event_handler);
143 	ib_dealloc_pd(device->pd);
144 
145 	kfree(device->comps);
146 	device->comps = NULL;
147 	device->pd = NULL;
148 }
149 
150 /**
151  * iser_alloc_fmr_pool - Creates FMR pool and page_vector
152  *
153  * returns 0 on success, or errno code on failure
154  */
155 int iser_alloc_fmr_pool(struct ib_conn *ib_conn,
156 			unsigned cmds_max,
157 			unsigned int size)
158 {
159 	struct iser_device *device = ib_conn->device;
160 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
161 	struct iser_page_vec *page_vec;
162 	struct iser_fr_desc *desc;
163 	struct ib_fmr_pool *fmr_pool;
164 	struct ib_fmr_pool_param params;
165 	int ret;
166 
167 	INIT_LIST_HEAD(&fr_pool->list);
168 	spin_lock_init(&fr_pool->lock);
169 
170 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
171 	if (!desc)
172 		return -ENOMEM;
173 
174 	page_vec = kmalloc(sizeof(*page_vec) + (sizeof(u64) * size),
175 			   GFP_KERNEL);
176 	if (!page_vec) {
177 		ret = -ENOMEM;
178 		goto err_frpl;
179 	}
180 
181 	page_vec->pages = (u64 *)(page_vec + 1);
182 
183 	params.page_shift        = SHIFT_4K;
184 	params.max_pages_per_fmr = size;
185 	/* make the pool size twice the max number of SCSI commands *
186 	 * the ML is expected to queue, watermark for unmap at 50%  */
187 	params.pool_size	 = cmds_max * 2;
188 	params.dirty_watermark	 = cmds_max;
189 	params.cache		 = 0;
190 	params.flush_function	 = NULL;
191 	params.access		 = (IB_ACCESS_LOCAL_WRITE  |
192 				    IB_ACCESS_REMOTE_WRITE |
193 				    IB_ACCESS_REMOTE_READ);
194 
195 	fmr_pool = ib_create_fmr_pool(device->pd, &params);
196 	if (IS_ERR(fmr_pool)) {
197 		ret = PTR_ERR(fmr_pool);
198 		iser_err("FMR allocation failed, err %d\n", ret);
199 		goto err_fmr;
200 	}
201 
202 	desc->rsc.page_vec = page_vec;
203 	desc->rsc.fmr_pool = fmr_pool;
204 	list_add(&desc->list, &fr_pool->list);
205 
206 	return 0;
207 
208 err_fmr:
209 	kfree(page_vec);
210 err_frpl:
211 	kfree(desc);
212 
213 	return ret;
214 }
215 
216 /**
217  * iser_free_fmr_pool - releases the FMR pool and page vec
218  */
219 void iser_free_fmr_pool(struct ib_conn *ib_conn)
220 {
221 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
222 	struct iser_fr_desc *desc;
223 
224 	desc = list_first_entry(&fr_pool->list,
225 				struct iser_fr_desc, list);
226 	list_del(&desc->list);
227 
228 	iser_info("freeing conn %p fmr pool %p\n",
229 		  ib_conn, desc->rsc.fmr_pool);
230 
231 	ib_destroy_fmr_pool(desc->rsc.fmr_pool);
232 	kfree(desc->rsc.page_vec);
233 	kfree(desc);
234 }
235 
236 static struct iser_fr_desc *
237 iser_create_fastreg_desc(struct iser_device *device,
238 			 struct ib_pd *pd,
239 			 bool pi_enable,
240 			 unsigned int size)
241 {
242 	struct iser_fr_desc *desc;
243 	struct ib_device *ib_dev = device->ib_device;
244 	enum ib_mr_type mr_type;
245 	int ret;
246 
247 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
248 	if (!desc)
249 		return ERR_PTR(-ENOMEM);
250 
251 	if (ib_dev->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG)
252 		mr_type = IB_MR_TYPE_SG_GAPS;
253 	else
254 		mr_type = IB_MR_TYPE_MEM_REG;
255 
256 	desc->rsc.mr = ib_alloc_mr(pd, mr_type, size);
257 	if (IS_ERR(desc->rsc.mr)) {
258 		ret = PTR_ERR(desc->rsc.mr);
259 		iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
260 		goto err_alloc_mr;
261 	}
262 
263 	if (pi_enable) {
264 		desc->rsc.sig_mr = ib_alloc_mr_integrity(pd, size, size);
265 		if (IS_ERR(desc->rsc.sig_mr)) {
266 			ret = PTR_ERR(desc->rsc.sig_mr);
267 			iser_err("Failed to allocate sig_mr err=%d\n", ret);
268 			goto err_alloc_mr_integrity;
269 		}
270 	}
271 	desc->rsc.mr_valid = 0;
272 
273 	return desc;
274 
275 err_alloc_mr_integrity:
276 	ib_dereg_mr(desc->rsc.mr);
277 err_alloc_mr:
278 	kfree(desc);
279 
280 	return ERR_PTR(ret);
281 }
282 
283 static void iser_destroy_fastreg_desc(struct iser_fr_desc *desc)
284 {
285 	struct iser_reg_resources *res = &desc->rsc;
286 
287 	ib_dereg_mr(res->mr);
288 	if (res->sig_mr) {
289 		ib_dereg_mr(res->sig_mr);
290 		res->sig_mr = NULL;
291 	}
292 	kfree(desc);
293 }
294 
295 /**
296  * iser_alloc_fastreg_pool - Creates pool of fast_reg descriptors
297  * for fast registration work requests.
298  * returns 0 on success, or errno code on failure
299  */
300 int iser_alloc_fastreg_pool(struct ib_conn *ib_conn,
301 			    unsigned cmds_max,
302 			    unsigned int size)
303 {
304 	struct iser_device *device = ib_conn->device;
305 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
306 	struct iser_fr_desc *desc;
307 	int i, ret;
308 
309 	INIT_LIST_HEAD(&fr_pool->list);
310 	INIT_LIST_HEAD(&fr_pool->all_list);
311 	spin_lock_init(&fr_pool->lock);
312 	fr_pool->size = 0;
313 	for (i = 0; i < cmds_max; i++) {
314 		desc = iser_create_fastreg_desc(device, device->pd,
315 						ib_conn->pi_support, size);
316 		if (IS_ERR(desc)) {
317 			ret = PTR_ERR(desc);
318 			goto err;
319 		}
320 
321 		list_add_tail(&desc->list, &fr_pool->list);
322 		list_add_tail(&desc->all_list, &fr_pool->all_list);
323 		fr_pool->size++;
324 	}
325 
326 	return 0;
327 
328 err:
329 	iser_free_fastreg_pool(ib_conn);
330 	return ret;
331 }
332 
333 /**
334  * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
335  */
336 void iser_free_fastreg_pool(struct ib_conn *ib_conn)
337 {
338 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
339 	struct iser_fr_desc *desc, *tmp;
340 	int i = 0;
341 
342 	if (list_empty(&fr_pool->all_list))
343 		return;
344 
345 	iser_info("freeing conn %p fr pool\n", ib_conn);
346 
347 	list_for_each_entry_safe(desc, tmp, &fr_pool->all_list, all_list) {
348 		list_del(&desc->all_list);
349 		iser_destroy_fastreg_desc(desc);
350 		++i;
351 	}
352 
353 	if (i < fr_pool->size)
354 		iser_warn("pool still has %d regions registered\n",
355 			  fr_pool->size - i);
356 }
357 
358 /**
359  * iser_create_ib_conn_res - Queue-Pair (QP)
360  *
361  * returns 0 on success, -1 on failure
362  */
363 static int iser_create_ib_conn_res(struct ib_conn *ib_conn)
364 {
365 	struct iser_conn *iser_conn = to_iser_conn(ib_conn);
366 	struct iser_device	*device;
367 	struct ib_device	*ib_dev;
368 	struct ib_qp_init_attr	init_attr;
369 	int			ret = -ENOMEM;
370 	int index, min_index = 0;
371 
372 	BUG_ON(ib_conn->device == NULL);
373 
374 	device = ib_conn->device;
375 	ib_dev = device->ib_device;
376 
377 	memset(&init_attr, 0, sizeof init_attr);
378 
379 	mutex_lock(&ig.connlist_mutex);
380 	/* select the CQ with the minimal number of usages */
381 	for (index = 0; index < device->comps_used; index++) {
382 		if (device->comps[index].active_qps <
383 		    device->comps[min_index].active_qps)
384 			min_index = index;
385 	}
386 	ib_conn->comp = &device->comps[min_index];
387 	ib_conn->comp->active_qps++;
388 	mutex_unlock(&ig.connlist_mutex);
389 	iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
390 
391 	init_attr.event_handler = iser_qp_event_callback;
392 	init_attr.qp_context	= (void *)ib_conn;
393 	init_attr.send_cq	= ib_conn->comp->cq;
394 	init_attr.recv_cq	= ib_conn->comp->cq;
395 	init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
396 	init_attr.cap.max_send_sge = 2;
397 	init_attr.cap.max_recv_sge = 1;
398 	init_attr.sq_sig_type	= IB_SIGNAL_REQ_WR;
399 	init_attr.qp_type	= IB_QPT_RC;
400 	if (ib_conn->pi_support) {
401 		init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS + 1;
402 		init_attr.create_flags |= IB_QP_CREATE_INTEGRITY_EN;
403 		iser_conn->max_cmds =
404 			ISER_GET_MAX_XMIT_CMDS(ISER_QP_SIG_MAX_REQ_DTOS);
405 	} else {
406 		if (ib_dev->attrs.max_qp_wr > ISER_QP_MAX_REQ_DTOS) {
407 			init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS + 1;
408 			iser_conn->max_cmds =
409 				ISER_GET_MAX_XMIT_CMDS(ISER_QP_MAX_REQ_DTOS);
410 		} else {
411 			init_attr.cap.max_send_wr = ib_dev->attrs.max_qp_wr;
412 			iser_conn->max_cmds =
413 				ISER_GET_MAX_XMIT_CMDS(ib_dev->attrs.max_qp_wr);
414 			iser_dbg("device %s supports max_send_wr %d\n",
415 				 dev_name(&device->ib_device->dev),
416 				 ib_dev->attrs.max_qp_wr);
417 		}
418 	}
419 
420 	ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
421 	if (ret)
422 		goto out_err;
423 
424 	ib_conn->qp = ib_conn->cma_id->qp;
425 	iser_info("setting conn %p cma_id %p qp %p\n",
426 		  ib_conn, ib_conn->cma_id,
427 		  ib_conn->cma_id->qp);
428 	return ret;
429 
430 out_err:
431 	mutex_lock(&ig.connlist_mutex);
432 	ib_conn->comp->active_qps--;
433 	mutex_unlock(&ig.connlist_mutex);
434 	iser_err("unable to alloc mem or create resource, err %d\n", ret);
435 
436 	return ret;
437 }
438 
439 /**
440  * based on the resolved device node GUID see if there already allocated
441  * device for this device. If there's no such, create one.
442  */
443 static
444 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
445 {
446 	struct iser_device *device;
447 
448 	mutex_lock(&ig.device_list_mutex);
449 
450 	list_for_each_entry(device, &ig.device_list, ig_list)
451 		/* find if there's a match using the node GUID */
452 		if (device->ib_device->node_guid == cma_id->device->node_guid)
453 			goto inc_refcnt;
454 
455 	device = kzalloc(sizeof *device, GFP_KERNEL);
456 	if (device == NULL)
457 		goto out;
458 
459 	/* assign this device to the device */
460 	device->ib_device = cma_id->device;
461 	/* init the device and link it into ig device list */
462 	if (iser_create_device_ib_res(device)) {
463 		kfree(device);
464 		device = NULL;
465 		goto out;
466 	}
467 	list_add(&device->ig_list, &ig.device_list);
468 
469 inc_refcnt:
470 	device->refcount++;
471 out:
472 	mutex_unlock(&ig.device_list_mutex);
473 	return device;
474 }
475 
476 /* if there's no demand for this device, release it */
477 static void iser_device_try_release(struct iser_device *device)
478 {
479 	mutex_lock(&ig.device_list_mutex);
480 	device->refcount--;
481 	iser_info("device %p refcount %d\n", device, device->refcount);
482 	if (!device->refcount) {
483 		iser_free_device_ib_res(device);
484 		list_del(&device->ig_list);
485 		kfree(device);
486 	}
487 	mutex_unlock(&ig.device_list_mutex);
488 }
489 
490 /**
491  * Called with state mutex held
492  **/
493 static int iser_conn_state_comp_exch(struct iser_conn *iser_conn,
494 				     enum iser_conn_state comp,
495 				     enum iser_conn_state exch)
496 {
497 	int ret;
498 
499 	ret = (iser_conn->state == comp);
500 	if (ret)
501 		iser_conn->state = exch;
502 
503 	return ret;
504 }
505 
506 void iser_release_work(struct work_struct *work)
507 {
508 	struct iser_conn *iser_conn;
509 
510 	iser_conn = container_of(work, struct iser_conn, release_work);
511 
512 	/* Wait for conn_stop to complete */
513 	wait_for_completion(&iser_conn->stop_completion);
514 	/* Wait for IB resouces cleanup to complete */
515 	wait_for_completion(&iser_conn->ib_completion);
516 
517 	mutex_lock(&iser_conn->state_mutex);
518 	iser_conn->state = ISER_CONN_DOWN;
519 	mutex_unlock(&iser_conn->state_mutex);
520 
521 	iser_conn_release(iser_conn);
522 }
523 
524 /**
525  * iser_free_ib_conn_res - release IB related resources
526  * @iser_conn: iser connection struct
527  * @destroy: indicator if we need to try to release the
528  *     iser device and memory regoins pool (only iscsi
529  *     shutdown and DEVICE_REMOVAL will use this).
530  *
531  * This routine is called with the iser state mutex held
532  * so the cm_id removal is out of here. It is Safe to
533  * be invoked multiple times.
534  */
535 static void iser_free_ib_conn_res(struct iser_conn *iser_conn,
536 				  bool destroy)
537 {
538 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
539 	struct iser_device *device = ib_conn->device;
540 
541 	iser_info("freeing conn %p cma_id %p qp %p\n",
542 		  iser_conn, ib_conn->cma_id, ib_conn->qp);
543 
544 	if (ib_conn->qp != NULL) {
545 		mutex_lock(&ig.connlist_mutex);
546 		ib_conn->comp->active_qps--;
547 		mutex_unlock(&ig.connlist_mutex);
548 		rdma_destroy_qp(ib_conn->cma_id);
549 		ib_conn->qp = NULL;
550 	}
551 
552 	if (destroy) {
553 		if (iser_conn->rx_descs)
554 			iser_free_rx_descriptors(iser_conn);
555 
556 		if (device != NULL) {
557 			iser_device_try_release(device);
558 			ib_conn->device = NULL;
559 		}
560 	}
561 }
562 
563 /**
564  * Frees all conn objects and deallocs conn descriptor
565  */
566 void iser_conn_release(struct iser_conn *iser_conn)
567 {
568 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
569 
570 	mutex_lock(&ig.connlist_mutex);
571 	list_del(&iser_conn->conn_list);
572 	mutex_unlock(&ig.connlist_mutex);
573 
574 	mutex_lock(&iser_conn->state_mutex);
575 	/* In case we endup here without ep_disconnect being invoked. */
576 	if (iser_conn->state != ISER_CONN_DOWN) {
577 		iser_warn("iser conn %p state %d, expected state down.\n",
578 			  iser_conn, iser_conn->state);
579 		iscsi_destroy_endpoint(iser_conn->ep);
580 		iser_conn->state = ISER_CONN_DOWN;
581 	}
582 	/*
583 	 * In case we never got to bind stage, we still need to
584 	 * release IB resources (which is safe to call more than once).
585 	 */
586 	iser_free_ib_conn_res(iser_conn, true);
587 	mutex_unlock(&iser_conn->state_mutex);
588 
589 	if (ib_conn->cma_id != NULL) {
590 		rdma_destroy_id(ib_conn->cma_id);
591 		ib_conn->cma_id = NULL;
592 	}
593 
594 	kfree(iser_conn);
595 }
596 
597 /**
598  * triggers start of the disconnect procedures and wait for them to be done
599  * Called with state mutex held
600  */
601 int iser_conn_terminate(struct iser_conn *iser_conn)
602 {
603 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
604 	int err = 0;
605 
606 	/* terminate the iser conn only if the conn state is UP */
607 	if (!iser_conn_state_comp_exch(iser_conn, ISER_CONN_UP,
608 				       ISER_CONN_TERMINATING))
609 		return 0;
610 
611 	iser_info("iser_conn %p state %d\n", iser_conn, iser_conn->state);
612 
613 	/* suspend queuing of new iscsi commands */
614 	if (iser_conn->iscsi_conn)
615 		iscsi_suspend_queue(iser_conn->iscsi_conn);
616 
617 	/*
618 	 * In case we didn't already clean up the cma_id (peer initiated
619 	 * a disconnection), we need to Cause the CMA to change the QP
620 	 * state to ERROR.
621 	 */
622 	if (ib_conn->cma_id) {
623 		err = rdma_disconnect(ib_conn->cma_id);
624 		if (err)
625 			iser_err("Failed to disconnect, conn: 0x%p err %d\n",
626 				 iser_conn, err);
627 
628 		/* block until all flush errors are consumed */
629 		ib_drain_sq(ib_conn->qp);
630 	}
631 
632 	return 1;
633 }
634 
635 /**
636  * Called with state mutex held
637  **/
638 static void iser_connect_error(struct rdma_cm_id *cma_id)
639 {
640 	struct iser_conn *iser_conn;
641 
642 	iser_conn = (struct iser_conn *)cma_id->context;
643 	iser_conn->state = ISER_CONN_TERMINATING;
644 }
645 
646 static void
647 iser_calc_scsi_params(struct iser_conn *iser_conn,
648 		      unsigned int max_sectors)
649 {
650 	struct iser_device *device = iser_conn->ib_conn.device;
651 	struct ib_device_attr *attr = &device->ib_device->attrs;
652 	unsigned short sg_tablesize, sup_sg_tablesize;
653 	unsigned short reserved_mr_pages;
654 	u32 max_num_sg;
655 
656 	/*
657 	 * FRs without SG_GAPS or FMRs can only map up to a (device) page per
658 	 * entry, but if the first entry is misaligned we'll end up using two
659 	 * entries (head and tail) for a single page worth data, so one
660 	 * additional entry is required.
661 	 */
662 	if ((attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) &&
663 	    (attr->device_cap_flags & IB_DEVICE_SG_GAPS_REG))
664 		reserved_mr_pages = 0;
665 	else
666 		reserved_mr_pages = 1;
667 
668 	if (iser_conn->ib_conn.pi_support)
669 		max_num_sg = attr->max_pi_fast_reg_page_list_len;
670 	else
671 		max_num_sg = attr->max_fast_reg_page_list_len;
672 
673 	sg_tablesize = DIV_ROUND_UP(max_sectors * 512, SIZE_4K);
674 	if (attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS)
675 		sup_sg_tablesize =
676 			min_t(
677 			 uint, ISCSI_ISER_MAX_SG_TABLESIZE,
678 			 max_num_sg - reserved_mr_pages);
679 	else
680 		sup_sg_tablesize = ISCSI_ISER_MAX_SG_TABLESIZE;
681 
682 	iser_conn->scsi_sg_tablesize = min(sg_tablesize, sup_sg_tablesize);
683 	iser_conn->pages_per_mr =
684 		iser_conn->scsi_sg_tablesize + reserved_mr_pages;
685 }
686 
687 /**
688  * Called with state mutex held
689  **/
690 static void iser_addr_handler(struct rdma_cm_id *cma_id)
691 {
692 	struct iser_device *device;
693 	struct iser_conn   *iser_conn;
694 	struct ib_conn   *ib_conn;
695 	int    ret;
696 
697 	iser_conn = (struct iser_conn *)cma_id->context;
698 	if (iser_conn->state != ISER_CONN_PENDING)
699 		/* bailout */
700 		return;
701 
702 	ib_conn = &iser_conn->ib_conn;
703 	device = iser_device_find_by_ib_device(cma_id);
704 	if (!device) {
705 		iser_err("device lookup/creation failed\n");
706 		iser_connect_error(cma_id);
707 		return;
708 	}
709 
710 	ib_conn->device = device;
711 
712 	/* connection T10-PI support */
713 	if (iser_pi_enable) {
714 		if (!(device->ib_device->attrs.device_cap_flags &
715 		      IB_DEVICE_INTEGRITY_HANDOVER)) {
716 			iser_warn("T10-PI requested but not supported on %s, "
717 				  "continue without T10-PI\n",
718 				  dev_name(&ib_conn->device->ib_device->dev));
719 			ib_conn->pi_support = false;
720 		} else {
721 			ib_conn->pi_support = true;
722 		}
723 	}
724 
725 	iser_calc_scsi_params(iser_conn, iser_max_sectors);
726 
727 	ret = rdma_resolve_route(cma_id, 1000);
728 	if (ret) {
729 		iser_err("resolve route failed: %d\n", ret);
730 		iser_connect_error(cma_id);
731 		return;
732 	}
733 }
734 
735 /**
736  * Called with state mutex held
737  **/
738 static void iser_route_handler(struct rdma_cm_id *cma_id)
739 {
740 	struct rdma_conn_param conn_param;
741 	int    ret;
742 	struct iser_cm_hdr req_hdr;
743 	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
744 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
745 	struct iser_device *device = ib_conn->device;
746 
747 	if (iser_conn->state != ISER_CONN_PENDING)
748 		/* bailout */
749 		return;
750 
751 	ret = iser_create_ib_conn_res(ib_conn);
752 	if (ret)
753 		goto failure;
754 
755 	memset(&conn_param, 0, sizeof conn_param);
756 	conn_param.responder_resources = device->ib_device->attrs.max_qp_rd_atom;
757 	conn_param.initiator_depth     = 1;
758 	conn_param.retry_count	       = 7;
759 	conn_param.rnr_retry_count     = 6;
760 
761 	memset(&req_hdr, 0, sizeof(req_hdr));
762 	req_hdr.flags = ISER_ZBVA_NOT_SUP;
763 	if (!device->remote_inv_sup)
764 		req_hdr.flags |= ISER_SEND_W_INV_NOT_SUP;
765 	conn_param.private_data	= (void *)&req_hdr;
766 	conn_param.private_data_len = sizeof(struct iser_cm_hdr);
767 
768 	ret = rdma_connect(cma_id, &conn_param);
769 	if (ret) {
770 		iser_err("failure connecting: %d\n", ret);
771 		goto failure;
772 	}
773 
774 	return;
775 failure:
776 	iser_connect_error(cma_id);
777 }
778 
779 static void iser_connected_handler(struct rdma_cm_id *cma_id,
780 				   const void *private_data)
781 {
782 	struct iser_conn *iser_conn;
783 	struct ib_qp_attr attr;
784 	struct ib_qp_init_attr init_attr;
785 
786 	iser_conn = (struct iser_conn *)cma_id->context;
787 	if (iser_conn->state != ISER_CONN_PENDING)
788 		/* bailout */
789 		return;
790 
791 	(void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
792 	iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
793 
794 	if (private_data) {
795 		u8 flags = *(u8 *)private_data;
796 
797 		iser_conn->snd_w_inv = !(flags & ISER_SEND_W_INV_NOT_SUP);
798 	}
799 
800 	iser_info("conn %p: negotiated %s invalidation\n",
801 		  iser_conn, iser_conn->snd_w_inv ? "remote" : "local");
802 
803 	iser_conn->state = ISER_CONN_UP;
804 	complete(&iser_conn->up_completion);
805 }
806 
807 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
808 {
809 	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
810 
811 	if (iser_conn_terminate(iser_conn)) {
812 		if (iser_conn->iscsi_conn)
813 			iscsi_conn_failure(iser_conn->iscsi_conn,
814 					   ISCSI_ERR_CONN_FAILED);
815 		else
816 			iser_err("iscsi_iser connection isn't bound\n");
817 	}
818 }
819 
820 static void iser_cleanup_handler(struct rdma_cm_id *cma_id,
821 				 bool destroy)
822 {
823 	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
824 
825 	/*
826 	 * We are not guaranteed that we visited disconnected_handler
827 	 * by now, call it here to be safe that we handle CM drep
828 	 * and flush errors.
829 	 */
830 	iser_disconnected_handler(cma_id);
831 	iser_free_ib_conn_res(iser_conn, destroy);
832 	complete(&iser_conn->ib_completion);
833 };
834 
835 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
836 {
837 	struct iser_conn *iser_conn;
838 	int ret = 0;
839 
840 	iser_conn = (struct iser_conn *)cma_id->context;
841 	iser_info("%s (%d): status %d conn %p id %p\n",
842 		  rdma_event_msg(event->event), event->event,
843 		  event->status, cma_id->context, cma_id);
844 
845 	mutex_lock(&iser_conn->state_mutex);
846 	switch (event->event) {
847 	case RDMA_CM_EVENT_ADDR_RESOLVED:
848 		iser_addr_handler(cma_id);
849 		break;
850 	case RDMA_CM_EVENT_ROUTE_RESOLVED:
851 		iser_route_handler(cma_id);
852 		break;
853 	case RDMA_CM_EVENT_ESTABLISHED:
854 		iser_connected_handler(cma_id, event->param.conn.private_data);
855 		break;
856 	case RDMA_CM_EVENT_REJECTED:
857 		iser_info("Connection rejected: %s\n",
858 			 rdma_reject_msg(cma_id, event->status));
859 		/* FALLTHROUGH */
860 	case RDMA_CM_EVENT_ADDR_ERROR:
861 	case RDMA_CM_EVENT_ROUTE_ERROR:
862 	case RDMA_CM_EVENT_CONNECT_ERROR:
863 	case RDMA_CM_EVENT_UNREACHABLE:
864 		iser_connect_error(cma_id);
865 		break;
866 	case RDMA_CM_EVENT_DISCONNECTED:
867 	case RDMA_CM_EVENT_ADDR_CHANGE:
868 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
869 		iser_cleanup_handler(cma_id, false);
870 		break;
871 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
872 		/*
873 		 * we *must* destroy the device as we cannot rely
874 		 * on iscsid to be around to initiate error handling.
875 		 * also if we are not in state DOWN implicitly destroy
876 		 * the cma_id.
877 		 */
878 		iser_cleanup_handler(cma_id, true);
879 		if (iser_conn->state != ISER_CONN_DOWN) {
880 			iser_conn->ib_conn.cma_id = NULL;
881 			ret = 1;
882 		}
883 		break;
884 	default:
885 		iser_err("Unexpected RDMA CM event: %s (%d)\n",
886 			 rdma_event_msg(event->event), event->event);
887 		break;
888 	}
889 	mutex_unlock(&iser_conn->state_mutex);
890 
891 	return ret;
892 }
893 
894 void iser_conn_init(struct iser_conn *iser_conn)
895 {
896 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
897 
898 	iser_conn->state = ISER_CONN_INIT;
899 	init_completion(&iser_conn->stop_completion);
900 	init_completion(&iser_conn->ib_completion);
901 	init_completion(&iser_conn->up_completion);
902 	INIT_LIST_HEAD(&iser_conn->conn_list);
903 	mutex_init(&iser_conn->state_mutex);
904 
905 	ib_conn->post_recv_buf_count = 0;
906 	ib_conn->reg_cqe.done = iser_reg_comp;
907 }
908 
909  /**
910  * starts the process of connecting to the target
911  * sleeps until the connection is established or rejected
912  */
913 int iser_connect(struct iser_conn   *iser_conn,
914 		 struct sockaddr    *src_addr,
915 		 struct sockaddr    *dst_addr,
916 		 int                 non_blocking)
917 {
918 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
919 	int err = 0;
920 
921 	mutex_lock(&iser_conn->state_mutex);
922 
923 	sprintf(iser_conn->name, "%pISp", dst_addr);
924 
925 	iser_info("connecting to: %s\n", iser_conn->name);
926 
927 	/* the device is known only --after-- address resolution */
928 	ib_conn->device = NULL;
929 
930 	iser_conn->state = ISER_CONN_PENDING;
931 
932 	ib_conn->cma_id = rdma_create_id(&init_net, iser_cma_handler,
933 					 (void *)iser_conn,
934 					 RDMA_PS_TCP, IB_QPT_RC);
935 	if (IS_ERR(ib_conn->cma_id)) {
936 		err = PTR_ERR(ib_conn->cma_id);
937 		iser_err("rdma_create_id failed: %d\n", err);
938 		goto id_failure;
939 	}
940 
941 	err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
942 	if (err) {
943 		iser_err("rdma_resolve_addr failed: %d\n", err);
944 		goto addr_failure;
945 	}
946 
947 	if (!non_blocking) {
948 		wait_for_completion_interruptible(&iser_conn->up_completion);
949 
950 		if (iser_conn->state != ISER_CONN_UP) {
951 			err =  -EIO;
952 			goto connect_failure;
953 		}
954 	}
955 	mutex_unlock(&iser_conn->state_mutex);
956 
957 	mutex_lock(&ig.connlist_mutex);
958 	list_add(&iser_conn->conn_list, &ig.connlist);
959 	mutex_unlock(&ig.connlist_mutex);
960 	return 0;
961 
962 id_failure:
963 	ib_conn->cma_id = NULL;
964 addr_failure:
965 	iser_conn->state = ISER_CONN_DOWN;
966 connect_failure:
967 	mutex_unlock(&iser_conn->state_mutex);
968 	iser_conn_release(iser_conn);
969 	return err;
970 }
971 
972 int iser_post_recvl(struct iser_conn *iser_conn)
973 {
974 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
975 	struct iser_login_desc *desc = &iser_conn->login_desc;
976 	struct ib_recv_wr wr;
977 	int ib_ret;
978 
979 	desc->sge.addr = desc->rsp_dma;
980 	desc->sge.length = ISER_RX_LOGIN_SIZE;
981 	desc->sge.lkey = ib_conn->device->pd->local_dma_lkey;
982 
983 	desc->cqe.done = iser_login_rsp;
984 	wr.wr_cqe = &desc->cqe;
985 	wr.sg_list = &desc->sge;
986 	wr.num_sge = 1;
987 	wr.next = NULL;
988 
989 	ib_conn->post_recv_buf_count++;
990 	ib_ret = ib_post_recv(ib_conn->qp, &wr, NULL);
991 	if (ib_ret) {
992 		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
993 		ib_conn->post_recv_buf_count--;
994 	}
995 
996 	return ib_ret;
997 }
998 
999 int iser_post_recvm(struct iser_conn *iser_conn, int count)
1000 {
1001 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
1002 	unsigned int my_rx_head = iser_conn->rx_desc_head;
1003 	struct iser_rx_desc *rx_desc;
1004 	struct ib_recv_wr *wr;
1005 	int i, ib_ret;
1006 
1007 	for (wr = ib_conn->rx_wr, i = 0; i < count; i++, wr++) {
1008 		rx_desc = &iser_conn->rx_descs[my_rx_head];
1009 		rx_desc->cqe.done = iser_task_rsp;
1010 		wr->wr_cqe = &rx_desc->cqe;
1011 		wr->sg_list = &rx_desc->rx_sg;
1012 		wr->num_sge = 1;
1013 		wr->next = wr + 1;
1014 		my_rx_head = (my_rx_head + 1) & iser_conn->qp_max_recv_dtos_mask;
1015 	}
1016 
1017 	wr--;
1018 	wr->next = NULL; /* mark end of work requests list */
1019 
1020 	ib_conn->post_recv_buf_count += count;
1021 	ib_ret = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, NULL);
1022 	if (ib_ret) {
1023 		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1024 		ib_conn->post_recv_buf_count -= count;
1025 	} else
1026 		iser_conn->rx_desc_head = my_rx_head;
1027 
1028 	return ib_ret;
1029 }
1030 
1031 
1032 /**
1033  * iser_start_send - Initiate a Send DTO operation
1034  *
1035  * returns 0 on success, -1 on failure
1036  */
1037 int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
1038 		   bool signal)
1039 {
1040 	struct ib_send_wr *wr = &tx_desc->send_wr;
1041 	struct ib_send_wr *first_wr;
1042 	int ib_ret;
1043 
1044 	ib_dma_sync_single_for_device(ib_conn->device->ib_device,
1045 				      tx_desc->dma_addr, ISER_HEADERS_LEN,
1046 				      DMA_TO_DEVICE);
1047 
1048 	wr->next = NULL;
1049 	wr->wr_cqe = &tx_desc->cqe;
1050 	wr->sg_list = tx_desc->tx_sg;
1051 	wr->num_sge = tx_desc->num_sge;
1052 	wr->opcode = IB_WR_SEND;
1053 	wr->send_flags = signal ? IB_SEND_SIGNALED : 0;
1054 
1055 	if (tx_desc->inv_wr.next)
1056 		first_wr = &tx_desc->inv_wr;
1057 	else if (tx_desc->reg_wr.wr.next)
1058 		first_wr = &tx_desc->reg_wr.wr;
1059 	else
1060 		first_wr = wr;
1061 
1062 	ib_ret = ib_post_send(ib_conn->qp, first_wr, NULL);
1063 	if (ib_ret)
1064 		iser_err("ib_post_send failed, ret:%d opcode:%d\n",
1065 			 ib_ret, wr->opcode);
1066 
1067 	return ib_ret;
1068 }
1069 
1070 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
1071 			     enum iser_data_dir cmd_dir, sector_t *sector)
1072 {
1073 	struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
1074 	struct iser_fr_desc *desc = reg->mem_h;
1075 	unsigned long sector_size = iser_task->sc->device->sector_size;
1076 	struct ib_mr_status mr_status;
1077 	int ret;
1078 
1079 	if (desc && desc->sig_protected) {
1080 		desc->sig_protected = 0;
1081 		ret = ib_check_mr_status(desc->rsc.sig_mr,
1082 					 IB_MR_CHECK_SIG_STATUS, &mr_status);
1083 		if (ret) {
1084 			pr_err("ib_check_mr_status failed, ret %d\n", ret);
1085 			/* Not a lot we can do, return ambiguous guard error */
1086 			*sector = 0;
1087 			return 0x1;
1088 		}
1089 
1090 		if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1091 			sector_t sector_off = mr_status.sig_err.sig_err_offset;
1092 
1093 			sector_div(sector_off, sector_size + 8);
1094 			*sector = scsi_get_lba(iser_task->sc) + sector_off;
1095 
1096 			pr_err("PI error found type %d at sector %llx "
1097 			       "expected %x vs actual %x\n",
1098 			       mr_status.sig_err.err_type,
1099 			       (unsigned long long)*sector,
1100 			       mr_status.sig_err.expected,
1101 			       mr_status.sig_err.actual);
1102 
1103 			switch (mr_status.sig_err.err_type) {
1104 			case IB_SIG_BAD_GUARD:
1105 				return 0x1;
1106 			case IB_SIG_BAD_REFTAG:
1107 				return 0x3;
1108 			case IB_SIG_BAD_APPTAG:
1109 				return 0x2;
1110 			}
1111 		}
1112 	}
1113 
1114 	return 0;
1115 }
1116 
1117 void iser_err_comp(struct ib_wc *wc, const char *type)
1118 {
1119 	if (wc->status != IB_WC_WR_FLUSH_ERR) {
1120 		struct iser_conn *iser_conn = to_iser_conn(wc->qp->qp_context);
1121 
1122 		iser_err("%s failure: %s (%d) vend_err %#x\n", type,
1123 			 ib_wc_status_msg(wc->status), wc->status,
1124 			 wc->vendor_err);
1125 
1126 		if (iser_conn->iscsi_conn)
1127 			iscsi_conn_failure(iser_conn->iscsi_conn,
1128 					   ISCSI_ERR_CONN_FAILED);
1129 	} else {
1130 		iser_dbg("%s failure: %s (%d)\n", type,
1131 			 ib_wc_status_msg(wc->status), wc->status);
1132 	}
1133 }
1134