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/slab.h>
36 #include <linux/delay.h>
37 
38 #include "iscsi_iser.h"
39 
iser_qp_event_callback(struct ib_event * cause,void * context)40 static void iser_qp_event_callback(struct ib_event *cause, void *context)
41 {
42 	iser_err("qp event %s (%d)\n",
43 		 ib_event_msg(cause->event), cause->event);
44 }
45 
iser_event_handler(struct ib_event_handler * handler,struct ib_event * event)46 static void iser_event_handler(struct ib_event_handler *handler,
47 				struct ib_event *event)
48 {
49 	iser_err("async event %s (%d) on device %s port %d\n",
50 		 ib_event_msg(event->event), event->event,
51 		dev_name(&event->device->dev), event->element.port_num);
52 }
53 
54 /*
55  * iser_create_device_ib_res - creates Protection Domain (PD), Completion
56  * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
57  * the adaptor.
58  *
59  * Return: 0 on success, -1 on failure
60  */
iser_create_device_ib_res(struct iser_device * device)61 static int iser_create_device_ib_res(struct iser_device *device)
62 {
63 	struct ib_device *ib_dev = device->ib_device;
64 
65 	if (!(ib_dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS)) {
66 		iser_err("IB device does not support memory registrations\n");
67 		return -1;
68 	}
69 
70 	device->pd = ib_alloc_pd(ib_dev,
71 		iser_always_reg ? 0 : IB_PD_UNSAFE_GLOBAL_RKEY);
72 	if (IS_ERR(device->pd))
73 		goto pd_err;
74 
75 	INIT_IB_EVENT_HANDLER(&device->event_handler, ib_dev,
76 			      iser_event_handler);
77 	ib_register_event_handler(&device->event_handler);
78 	return 0;
79 
80 pd_err:
81 	iser_err("failed to allocate an IB resource\n");
82 	return -1;
83 }
84 
85 /*
86  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
87  * CQ and PD created with the device associated with the adaptor.
88  */
iser_free_device_ib_res(struct iser_device * device)89 static void iser_free_device_ib_res(struct iser_device *device)
90 {
91 	ib_unregister_event_handler(&device->event_handler);
92 	ib_dealloc_pd(device->pd);
93 
94 	device->pd = NULL;
95 }
96 
97 static struct iser_fr_desc *
iser_create_fastreg_desc(struct iser_device * device,struct ib_pd * pd,bool pi_enable,unsigned int size)98 iser_create_fastreg_desc(struct iser_device *device,
99 			 struct ib_pd *pd,
100 			 bool pi_enable,
101 			 unsigned int size)
102 {
103 	struct iser_fr_desc *desc;
104 	struct ib_device *ib_dev = device->ib_device;
105 	enum ib_mr_type mr_type;
106 	int ret;
107 
108 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
109 	if (!desc)
110 		return ERR_PTR(-ENOMEM);
111 
112 	if (ib_dev->attrs.kernel_cap_flags & IBK_SG_GAPS_REG)
113 		mr_type = IB_MR_TYPE_SG_GAPS;
114 	else
115 		mr_type = IB_MR_TYPE_MEM_REG;
116 
117 	desc->rsc.mr = ib_alloc_mr(pd, mr_type, size);
118 	if (IS_ERR(desc->rsc.mr)) {
119 		ret = PTR_ERR(desc->rsc.mr);
120 		iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
121 		goto err_alloc_mr;
122 	}
123 
124 	if (pi_enable) {
125 		desc->rsc.sig_mr = ib_alloc_mr_integrity(pd, size, size);
126 		if (IS_ERR(desc->rsc.sig_mr)) {
127 			ret = PTR_ERR(desc->rsc.sig_mr);
128 			iser_err("Failed to allocate sig_mr err=%d\n", ret);
129 			goto err_alloc_mr_integrity;
130 		}
131 	}
132 
133 	return desc;
134 
135 err_alloc_mr_integrity:
136 	ib_dereg_mr(desc->rsc.mr);
137 err_alloc_mr:
138 	kfree(desc);
139 
140 	return ERR_PTR(ret);
141 }
142 
iser_destroy_fastreg_desc(struct iser_fr_desc * desc)143 static void iser_destroy_fastreg_desc(struct iser_fr_desc *desc)
144 {
145 	struct iser_reg_resources *res = &desc->rsc;
146 
147 	ib_dereg_mr(res->mr);
148 	if (res->sig_mr) {
149 		ib_dereg_mr(res->sig_mr);
150 		res->sig_mr = NULL;
151 	}
152 	kfree(desc);
153 }
154 
155 /**
156  * iser_alloc_fastreg_pool - Creates pool of fast_reg descriptors
157  * for fast registration work requests.
158  * @ib_conn: connection RDMA resources
159  * @cmds_max: max number of SCSI commands for this connection
160  * @size: max number of pages per map request
161  *
162  * Return: 0 on success, or errno code on failure
163  */
iser_alloc_fastreg_pool(struct ib_conn * ib_conn,unsigned cmds_max,unsigned int size)164 int iser_alloc_fastreg_pool(struct ib_conn *ib_conn,
165 			    unsigned cmds_max,
166 			    unsigned int size)
167 {
168 	struct iser_device *device = ib_conn->device;
169 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
170 	struct iser_fr_desc *desc;
171 	int i, ret;
172 
173 	INIT_LIST_HEAD(&fr_pool->list);
174 	INIT_LIST_HEAD(&fr_pool->all_list);
175 	spin_lock_init(&fr_pool->lock);
176 	fr_pool->size = 0;
177 	for (i = 0; i < cmds_max; i++) {
178 		desc = iser_create_fastreg_desc(device, device->pd,
179 						ib_conn->pi_support, size);
180 		if (IS_ERR(desc)) {
181 			ret = PTR_ERR(desc);
182 			goto err;
183 		}
184 
185 		list_add_tail(&desc->list, &fr_pool->list);
186 		list_add_tail(&desc->all_list, &fr_pool->all_list);
187 		fr_pool->size++;
188 	}
189 
190 	return 0;
191 
192 err:
193 	iser_free_fastreg_pool(ib_conn);
194 	return ret;
195 }
196 
197 /**
198  * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
199  * @ib_conn: connection RDMA resources
200  */
iser_free_fastreg_pool(struct ib_conn * ib_conn)201 void iser_free_fastreg_pool(struct ib_conn *ib_conn)
202 {
203 	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
204 	struct iser_fr_desc *desc, *tmp;
205 	int i = 0;
206 
207 	if (list_empty(&fr_pool->all_list))
208 		return;
209 
210 	iser_info("freeing conn %p fr pool\n", ib_conn);
211 
212 	list_for_each_entry_safe(desc, tmp, &fr_pool->all_list, all_list) {
213 		list_del(&desc->all_list);
214 		iser_destroy_fastreg_desc(desc);
215 		++i;
216 	}
217 
218 	if (i < fr_pool->size)
219 		iser_warn("pool still has %d regions registered\n",
220 			  fr_pool->size - i);
221 }
222 
223 /*
224  * iser_create_ib_conn_res - Queue-Pair (QP)
225  *
226  * Return: 0 on success, -1 on failure
227  */
iser_create_ib_conn_res(struct ib_conn * ib_conn)228 static int iser_create_ib_conn_res(struct ib_conn *ib_conn)
229 {
230 	struct iser_conn *iser_conn = to_iser_conn(ib_conn);
231 	struct iser_device	*device;
232 	struct ib_device	*ib_dev;
233 	struct ib_qp_init_attr	init_attr;
234 	int			ret = -ENOMEM;
235 	unsigned int max_send_wr, cq_size;
236 
237 	BUG_ON(ib_conn->device == NULL);
238 
239 	device = ib_conn->device;
240 	ib_dev = device->ib_device;
241 
242 	/* +1 for drain */
243 	if (ib_conn->pi_support)
244 		max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS + 1;
245 	else
246 		max_send_wr = ISER_QP_MAX_REQ_DTOS + 1;
247 	max_send_wr = min_t(unsigned int, max_send_wr,
248 			    (unsigned int)ib_dev->attrs.max_qp_wr);
249 
250 	cq_size = max_send_wr + ISER_QP_MAX_RECV_DTOS;
251 	ib_conn->cq = ib_cq_pool_get(ib_dev, cq_size, -1, IB_POLL_SOFTIRQ);
252 	if (IS_ERR(ib_conn->cq)) {
253 		ret = PTR_ERR(ib_conn->cq);
254 		goto cq_err;
255 	}
256 	ib_conn->cq_size = cq_size;
257 
258 	memset(&init_attr, 0, sizeof(init_attr));
259 
260 	init_attr.event_handler = iser_qp_event_callback;
261 	init_attr.qp_context = (void *)ib_conn;
262 	init_attr.send_cq = ib_conn->cq;
263 	init_attr.recv_cq = ib_conn->cq;
264 	/* +1 for drain */
265 	init_attr.cap.max_recv_wr = ISER_QP_MAX_RECV_DTOS + 1;
266 	init_attr.cap.max_send_sge = 2;
267 	init_attr.cap.max_recv_sge = 1;
268 	init_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
269 	init_attr.qp_type = IB_QPT_RC;
270 	init_attr.cap.max_send_wr = max_send_wr;
271 	if (ib_conn->pi_support)
272 		init_attr.create_flags |= IB_QP_CREATE_INTEGRITY_EN;
273 	iser_conn->max_cmds = ISER_GET_MAX_XMIT_CMDS(max_send_wr - 1);
274 
275 	ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
276 	if (ret)
277 		goto out_err;
278 
279 	ib_conn->qp = ib_conn->cma_id->qp;
280 	iser_info("setting conn %p cma_id %p qp %p max_send_wr %d\n", ib_conn,
281 		  ib_conn->cma_id, ib_conn->cma_id->qp, max_send_wr);
282 	return ret;
283 
284 out_err:
285 	ib_cq_pool_put(ib_conn->cq, ib_conn->cq_size);
286 cq_err:
287 	iser_err("unable to alloc mem or create resource, err %d\n", ret);
288 
289 	return ret;
290 }
291 
292 /*
293  * based on the resolved device node GUID see if there already allocated
294  * device for this device. If there's no such, create one.
295  */
296 static
iser_device_find_by_ib_device(struct rdma_cm_id * cma_id)297 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
298 {
299 	struct iser_device *device;
300 
301 	mutex_lock(&ig.device_list_mutex);
302 
303 	list_for_each_entry(device, &ig.device_list, ig_list)
304 		/* find if there's a match using the node GUID */
305 		if (device->ib_device->node_guid == cma_id->device->node_guid)
306 			goto inc_refcnt;
307 
308 	device = kzalloc(sizeof *device, GFP_KERNEL);
309 	if (!device)
310 		goto out;
311 
312 	/* assign this device to the device */
313 	device->ib_device = cma_id->device;
314 	/* init the device and link it into ig device list */
315 	if (iser_create_device_ib_res(device)) {
316 		kfree(device);
317 		device = NULL;
318 		goto out;
319 	}
320 	list_add(&device->ig_list, &ig.device_list);
321 
322 inc_refcnt:
323 	device->refcount++;
324 out:
325 	mutex_unlock(&ig.device_list_mutex);
326 	return device;
327 }
328 
329 /* if there's no demand for this device, release it */
iser_device_try_release(struct iser_device * device)330 static void iser_device_try_release(struct iser_device *device)
331 {
332 	mutex_lock(&ig.device_list_mutex);
333 	device->refcount--;
334 	iser_info("device %p refcount %d\n", device, device->refcount);
335 	if (!device->refcount) {
336 		iser_free_device_ib_res(device);
337 		list_del(&device->ig_list);
338 		kfree(device);
339 	}
340 	mutex_unlock(&ig.device_list_mutex);
341 }
342 
iser_release_work(struct work_struct * work)343 void iser_release_work(struct work_struct *work)
344 {
345 	struct iser_conn *iser_conn;
346 
347 	iser_conn = container_of(work, struct iser_conn, release_work);
348 
349 	/* Wait for conn_stop to complete */
350 	wait_for_completion(&iser_conn->stop_completion);
351 	/* Wait for IB resouces cleanup to complete */
352 	wait_for_completion(&iser_conn->ib_completion);
353 
354 	mutex_lock(&iser_conn->state_mutex);
355 	iser_conn->state = ISER_CONN_DOWN;
356 	mutex_unlock(&iser_conn->state_mutex);
357 
358 	iser_conn_release(iser_conn);
359 }
360 
361 /**
362  * iser_free_ib_conn_res - release IB related resources
363  * @iser_conn: iser connection struct
364  * @destroy: indicator if we need to try to release the
365  *     iser device and memory regoins pool (only iscsi
366  *     shutdown and DEVICE_REMOVAL will use this).
367  *
368  * This routine is called with the iser state mutex held
369  * so the cm_id removal is out of here. It is Safe to
370  * be invoked multiple times.
371  */
iser_free_ib_conn_res(struct iser_conn * iser_conn,bool destroy)372 static void iser_free_ib_conn_res(struct iser_conn *iser_conn, bool destroy)
373 {
374 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
375 	struct iser_device *device = ib_conn->device;
376 
377 	iser_info("freeing conn %p cma_id %p qp %p\n",
378 		  iser_conn, ib_conn->cma_id, ib_conn->qp);
379 
380 	if (ib_conn->qp) {
381 		rdma_destroy_qp(ib_conn->cma_id);
382 		ib_cq_pool_put(ib_conn->cq, ib_conn->cq_size);
383 		ib_conn->qp = NULL;
384 	}
385 
386 	if (destroy) {
387 		if (iser_conn->rx_descs)
388 			iser_free_rx_descriptors(iser_conn);
389 
390 		if (device) {
391 			iser_device_try_release(device);
392 			ib_conn->device = NULL;
393 		}
394 	}
395 }
396 
397 /**
398  * iser_conn_release - Frees all conn objects and deallocs conn descriptor
399  * @iser_conn: iSER connection context
400  */
iser_conn_release(struct iser_conn * iser_conn)401 void iser_conn_release(struct iser_conn *iser_conn)
402 {
403 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
404 
405 	mutex_lock(&ig.connlist_mutex);
406 	list_del(&iser_conn->conn_list);
407 	mutex_unlock(&ig.connlist_mutex);
408 
409 	mutex_lock(&iser_conn->state_mutex);
410 	/* In case we endup here without ep_disconnect being invoked. */
411 	if (iser_conn->state != ISER_CONN_DOWN) {
412 		iser_warn("iser conn %p state %d, expected state down.\n",
413 			  iser_conn, iser_conn->state);
414 		iscsi_destroy_endpoint(iser_conn->ep);
415 		iser_conn->state = ISER_CONN_DOWN;
416 	}
417 	/*
418 	 * In case we never got to bind stage, we still need to
419 	 * release IB resources (which is safe to call more than once).
420 	 */
421 	iser_free_ib_conn_res(iser_conn, true);
422 	mutex_unlock(&iser_conn->state_mutex);
423 
424 	if (ib_conn->cma_id) {
425 		rdma_destroy_id(ib_conn->cma_id);
426 		ib_conn->cma_id = NULL;
427 	}
428 
429 	kfree(iser_conn);
430 }
431 
432 /**
433  * iser_conn_terminate - triggers start of the disconnect procedures and
434  * waits for them to be done
435  * @iser_conn: iSER connection context
436  *
437  * Called with state mutex held
438  */
iser_conn_terminate(struct iser_conn * iser_conn)439 int iser_conn_terminate(struct iser_conn *iser_conn)
440 {
441 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
442 	int err = 0;
443 
444 	lockdep_assert_held(&iser_conn->state_mutex);
445 
446 	/* terminate the iser conn only if the conn state is UP */
447 	if (iser_conn->state != ISER_CONN_UP)
448 		return 0;
449 
450 	iser_conn->state = ISER_CONN_TERMINATING;
451 	iser_info("iser_conn %p state %d\n", iser_conn, iser_conn->state);
452 
453 	/* suspend queuing of new iscsi commands */
454 	if (iser_conn->iscsi_conn)
455 		iscsi_suspend_queue(iser_conn->iscsi_conn);
456 
457 	/*
458 	 * In case we didn't already clean up the cma_id (peer initiated
459 	 * a disconnection), we need to Cause the CMA to change the QP
460 	 * state to ERROR.
461 	 */
462 	if (ib_conn->cma_id) {
463 		err = rdma_disconnect(ib_conn->cma_id);
464 		if (err)
465 			iser_err("Failed to disconnect, conn: 0x%p err %d\n",
466 				 iser_conn, err);
467 
468 		/* block until all flush errors are consumed */
469 		ib_drain_qp(ib_conn->qp);
470 	}
471 
472 	return 1;
473 }
474 
475 /*
476  * Called with state mutex held
477  */
iser_connect_error(struct rdma_cm_id * cma_id)478 static void iser_connect_error(struct rdma_cm_id *cma_id)
479 {
480 	struct iser_conn *iser_conn = cma_id->context;
481 
482 	lockdep_assert_held(&iser_conn->state_mutex);
483 
484 	iser_conn->state = ISER_CONN_TERMINATING;
485 }
486 
iser_calc_scsi_params(struct iser_conn * iser_conn,unsigned int max_sectors)487 static void iser_calc_scsi_params(struct iser_conn *iser_conn,
488 				  unsigned int max_sectors)
489 {
490 	struct iser_device *device = iser_conn->ib_conn.device;
491 	struct ib_device_attr *attr = &device->ib_device->attrs;
492 	unsigned short sg_tablesize, sup_sg_tablesize;
493 	unsigned short reserved_mr_pages;
494 	u32 max_num_sg;
495 
496 	/*
497 	 * FRs without SG_GAPS can only map up to a (device) page per entry,
498 	 * but if the first entry is misaligned we'll end up using two entries
499 	 * (head and tail) for a single page worth data, so one additional
500 	 * entry is required.
501 	 */
502 	if (attr->kernel_cap_flags & IBK_SG_GAPS_REG)
503 		reserved_mr_pages = 0;
504 	else
505 		reserved_mr_pages = 1;
506 
507 	if (iser_conn->ib_conn.pi_support)
508 		max_num_sg = attr->max_pi_fast_reg_page_list_len;
509 	else
510 		max_num_sg = attr->max_fast_reg_page_list_len;
511 
512 	sg_tablesize = DIV_ROUND_UP(max_sectors * SECTOR_SIZE, SZ_4K);
513 	sup_sg_tablesize = min_t(uint, ISCSI_ISER_MAX_SG_TABLESIZE,
514 				 max_num_sg - reserved_mr_pages);
515 	iser_conn->scsi_sg_tablesize = min(sg_tablesize, sup_sg_tablesize);
516 	iser_conn->pages_per_mr =
517 		iser_conn->scsi_sg_tablesize + reserved_mr_pages;
518 }
519 
520 /*
521  * Called with state mutex held
522  */
iser_addr_handler(struct rdma_cm_id * cma_id)523 static void iser_addr_handler(struct rdma_cm_id *cma_id)
524 {
525 	struct iser_conn *iser_conn = cma_id->context;
526 	struct iser_device *device;
527 	struct ib_conn *ib_conn;
528 	int    ret;
529 
530 	lockdep_assert_held(&iser_conn->state_mutex);
531 
532 	if (iser_conn->state != ISER_CONN_PENDING)
533 		/* bailout */
534 		return;
535 
536 	ib_conn = &iser_conn->ib_conn;
537 	device = iser_device_find_by_ib_device(cma_id);
538 	if (!device) {
539 		iser_err("device lookup/creation failed\n");
540 		iser_connect_error(cma_id);
541 		return;
542 	}
543 
544 	ib_conn->device = device;
545 
546 	/* connection T10-PI support */
547 	if (iser_pi_enable) {
548 		if (!(device->ib_device->attrs.kernel_cap_flags &
549 		      IBK_INTEGRITY_HANDOVER)) {
550 			iser_warn("T10-PI requested but not supported on %s, "
551 				  "continue without T10-PI\n",
552 				  dev_name(&ib_conn->device->ib_device->dev));
553 			ib_conn->pi_support = false;
554 		} else {
555 			ib_conn->pi_support = true;
556 		}
557 	}
558 
559 	iser_calc_scsi_params(iser_conn, iser_max_sectors);
560 
561 	ret = rdma_resolve_route(cma_id, 1000);
562 	if (ret) {
563 		iser_err("resolve route failed: %d\n", ret);
564 		iser_connect_error(cma_id);
565 		return;
566 	}
567 }
568 
569 /*
570  * Called with state mutex held
571  */
iser_route_handler(struct rdma_cm_id * cma_id)572 static void iser_route_handler(struct rdma_cm_id *cma_id)
573 {
574 	struct rdma_conn_param conn_param;
575 	int ret;
576 	struct iser_cm_hdr req_hdr;
577 	struct iser_conn *iser_conn = cma_id->context;
578 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
579 	struct ib_device *ib_dev = ib_conn->device->ib_device;
580 
581 	lockdep_assert_held(&iser_conn->state_mutex);
582 
583 	if (iser_conn->state != ISER_CONN_PENDING)
584 		/* bailout */
585 		return;
586 
587 	ret = iser_create_ib_conn_res(ib_conn);
588 	if (ret)
589 		goto failure;
590 
591 	memset(&conn_param, 0, sizeof conn_param);
592 	conn_param.responder_resources = ib_dev->attrs.max_qp_rd_atom;
593 	conn_param.initiator_depth = 1;
594 	conn_param.retry_count = 7;
595 	conn_param.rnr_retry_count = 6;
596 
597 	memset(&req_hdr, 0, sizeof(req_hdr));
598 	req_hdr.flags = ISER_ZBVA_NOT_SUP;
599 	if (!iser_always_reg)
600 		req_hdr.flags |= ISER_SEND_W_INV_NOT_SUP;
601 	conn_param.private_data	= (void *)&req_hdr;
602 	conn_param.private_data_len = sizeof(struct iser_cm_hdr);
603 
604 	ret = rdma_connect_locked(cma_id, &conn_param);
605 	if (ret) {
606 		iser_err("failure connecting: %d\n", ret);
607 		goto failure;
608 	}
609 
610 	return;
611 failure:
612 	iser_connect_error(cma_id);
613 }
614 
615 /*
616  * Called with state mutex held
617  */
iser_connected_handler(struct rdma_cm_id * cma_id,const void * private_data)618 static void iser_connected_handler(struct rdma_cm_id *cma_id,
619 				   const void *private_data)
620 {
621 	struct iser_conn *iser_conn = cma_id->context;
622 	struct ib_qp_attr attr;
623 	struct ib_qp_init_attr init_attr;
624 
625 	lockdep_assert_held(&iser_conn->state_mutex);
626 
627 	if (iser_conn->state != ISER_CONN_PENDING)
628 		/* bailout */
629 		return;
630 
631 	(void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
632 	iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
633 
634 	if (private_data) {
635 		u8 flags = *(u8 *)private_data;
636 
637 		iser_conn->snd_w_inv = !(flags & ISER_SEND_W_INV_NOT_SUP);
638 	}
639 
640 	iser_info("conn %p: negotiated %s invalidation\n",
641 		  iser_conn, iser_conn->snd_w_inv ? "remote" : "local");
642 
643 	iser_conn->state = ISER_CONN_UP;
644 	complete(&iser_conn->up_completion);
645 }
646 
647 /*
648  * Called with state mutex held
649  */
iser_cleanup_handler(struct rdma_cm_id * cma_id,bool destroy)650 static void iser_cleanup_handler(struct rdma_cm_id *cma_id,
651 				 bool destroy)
652 {
653 	struct iser_conn *iser_conn = cma_id->context;
654 
655 	lockdep_assert_held(&iser_conn->state_mutex);
656 	/*
657 	 * We are not guaranteed that we visited disconnected_handler
658 	 * by now, call it here to be safe that we handle CM drep
659 	 * and flush errors.
660 	 */
661 	if (iser_conn_terminate(iser_conn)) {
662 		if (iser_conn->iscsi_conn)
663 			iscsi_conn_failure(iser_conn->iscsi_conn,
664 					   ISCSI_ERR_CONN_FAILED);
665 		else
666 			iser_err("iscsi_iser connection isn't bound\n");
667 	}
668 	iser_free_ib_conn_res(iser_conn, destroy);
669 	complete(&iser_conn->ib_completion);
670 }
671 
iser_cma_handler(struct rdma_cm_id * cma_id,struct rdma_cm_event * event)672 static int iser_cma_handler(struct rdma_cm_id *cma_id,
673 			    struct rdma_cm_event *event)
674 {
675 	struct iser_conn *iser_conn;
676 	int ret = 0;
677 
678 	iser_conn = cma_id->context;
679 	iser_info("%s (%d): status %d conn %p id %p\n",
680 		  rdma_event_msg(event->event), event->event,
681 		  event->status, cma_id->context, cma_id);
682 
683 	mutex_lock(&iser_conn->state_mutex);
684 	switch (event->event) {
685 	case RDMA_CM_EVENT_ADDR_RESOLVED:
686 		iser_addr_handler(cma_id);
687 		break;
688 	case RDMA_CM_EVENT_ROUTE_RESOLVED:
689 		iser_route_handler(cma_id);
690 		break;
691 	case RDMA_CM_EVENT_ESTABLISHED:
692 		iser_connected_handler(cma_id, event->param.conn.private_data);
693 		break;
694 	case RDMA_CM_EVENT_REJECTED:
695 		iser_info("Connection rejected: %s\n",
696 			 rdma_reject_msg(cma_id, event->status));
697 		fallthrough;
698 	case RDMA_CM_EVENT_ADDR_ERROR:
699 	case RDMA_CM_EVENT_ROUTE_ERROR:
700 	case RDMA_CM_EVENT_CONNECT_ERROR:
701 	case RDMA_CM_EVENT_UNREACHABLE:
702 		iser_connect_error(cma_id);
703 		break;
704 	case RDMA_CM_EVENT_DISCONNECTED:
705 	case RDMA_CM_EVENT_ADDR_CHANGE:
706 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
707 		iser_cleanup_handler(cma_id, false);
708 		break;
709 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
710 		/*
711 		 * we *must* destroy the device as we cannot rely
712 		 * on iscsid to be around to initiate error handling.
713 		 * also if we are not in state DOWN implicitly destroy
714 		 * the cma_id.
715 		 */
716 		iser_cleanup_handler(cma_id, true);
717 		if (iser_conn->state != ISER_CONN_DOWN) {
718 			iser_conn->ib_conn.cma_id = NULL;
719 			ret = 1;
720 		}
721 		break;
722 	default:
723 		iser_err("Unexpected RDMA CM event: %s (%d)\n",
724 			 rdma_event_msg(event->event), event->event);
725 		break;
726 	}
727 	mutex_unlock(&iser_conn->state_mutex);
728 
729 	return ret;
730 }
731 
iser_conn_init(struct iser_conn * iser_conn)732 void iser_conn_init(struct iser_conn *iser_conn)
733 {
734 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
735 
736 	iser_conn->state = ISER_CONN_INIT;
737 	init_completion(&iser_conn->stop_completion);
738 	init_completion(&iser_conn->ib_completion);
739 	init_completion(&iser_conn->up_completion);
740 	INIT_LIST_HEAD(&iser_conn->conn_list);
741 	mutex_init(&iser_conn->state_mutex);
742 
743 	ib_conn->reg_cqe.done = iser_reg_comp;
744 }
745 
746 /*
747  * starts the process of connecting to the target
748  * sleeps until the connection is established or rejected
749  */
iser_connect(struct iser_conn * iser_conn,struct sockaddr * src_addr,struct sockaddr * dst_addr,int non_blocking)750 int iser_connect(struct iser_conn *iser_conn, struct sockaddr *src_addr,
751 		 struct sockaddr *dst_addr, int non_blocking)
752 {
753 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
754 	int err = 0;
755 
756 	mutex_lock(&iser_conn->state_mutex);
757 
758 	sprintf(iser_conn->name, "%pISp", dst_addr);
759 
760 	iser_info("connecting to: %s\n", iser_conn->name);
761 
762 	/* the device is known only --after-- address resolution */
763 	ib_conn->device = NULL;
764 
765 	iser_conn->state = ISER_CONN_PENDING;
766 
767 	ib_conn->cma_id = rdma_create_id(&init_net, iser_cma_handler,
768 					 iser_conn, RDMA_PS_TCP, IB_QPT_RC);
769 	if (IS_ERR(ib_conn->cma_id)) {
770 		err = PTR_ERR(ib_conn->cma_id);
771 		iser_err("rdma_create_id failed: %d\n", err);
772 		goto id_failure;
773 	}
774 
775 	err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
776 	if (err) {
777 		iser_err("rdma_resolve_addr failed: %d\n", err);
778 		goto addr_failure;
779 	}
780 
781 	if (!non_blocking) {
782 		wait_for_completion_interruptible(&iser_conn->up_completion);
783 
784 		if (iser_conn->state != ISER_CONN_UP) {
785 			err =  -EIO;
786 			goto connect_failure;
787 		}
788 	}
789 	mutex_unlock(&iser_conn->state_mutex);
790 
791 	mutex_lock(&ig.connlist_mutex);
792 	list_add(&iser_conn->conn_list, &ig.connlist);
793 	mutex_unlock(&ig.connlist_mutex);
794 	return 0;
795 
796 id_failure:
797 	ib_conn->cma_id = NULL;
798 addr_failure:
799 	iser_conn->state = ISER_CONN_DOWN;
800 connect_failure:
801 	mutex_unlock(&iser_conn->state_mutex);
802 	iser_conn_release(iser_conn);
803 	return err;
804 }
805 
iser_post_recvl(struct iser_conn * iser_conn)806 int iser_post_recvl(struct iser_conn *iser_conn)
807 {
808 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
809 	struct iser_login_desc *desc = &iser_conn->login_desc;
810 	struct ib_recv_wr wr;
811 	int ret;
812 
813 	desc->sge.addr = desc->rsp_dma;
814 	desc->sge.length = ISER_RX_LOGIN_SIZE;
815 	desc->sge.lkey = ib_conn->device->pd->local_dma_lkey;
816 
817 	desc->cqe.done = iser_login_rsp;
818 	wr.wr_cqe = &desc->cqe;
819 	wr.sg_list = &desc->sge;
820 	wr.num_sge = 1;
821 	wr.next = NULL;
822 
823 	ret = ib_post_recv(ib_conn->qp, &wr, NULL);
824 	if (unlikely(ret))
825 		iser_err("ib_post_recv login failed ret=%d\n", ret);
826 
827 	return ret;
828 }
829 
iser_post_recvm(struct iser_conn * iser_conn,struct iser_rx_desc * rx_desc)830 int iser_post_recvm(struct iser_conn *iser_conn, struct iser_rx_desc *rx_desc)
831 {
832 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
833 	struct ib_recv_wr wr;
834 	int ret;
835 
836 	rx_desc->cqe.done = iser_task_rsp;
837 	wr.wr_cqe = &rx_desc->cqe;
838 	wr.sg_list = &rx_desc->rx_sg;
839 	wr.num_sge = 1;
840 	wr.next = NULL;
841 
842 	ret = ib_post_recv(ib_conn->qp, &wr, NULL);
843 	if (unlikely(ret))
844 		iser_err("ib_post_recv failed ret=%d\n", ret);
845 
846 	return ret;
847 }
848 
849 
850 /**
851  * iser_post_send - Initiate a Send DTO operation
852  * @ib_conn: connection RDMA resources
853  * @tx_desc: iSER TX descriptor
854  *
855  * Return: 0 on success, -1 on failure
856  */
iser_post_send(struct ib_conn * ib_conn,struct iser_tx_desc * tx_desc)857 int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc)
858 {
859 	struct ib_send_wr *wr = &tx_desc->send_wr;
860 	struct ib_send_wr *first_wr;
861 	int ret;
862 
863 	ib_dma_sync_single_for_device(ib_conn->device->ib_device,
864 				      tx_desc->dma_addr, ISER_HEADERS_LEN,
865 				      DMA_TO_DEVICE);
866 
867 	wr->next = NULL;
868 	wr->wr_cqe = &tx_desc->cqe;
869 	wr->sg_list = tx_desc->tx_sg;
870 	wr->num_sge = tx_desc->num_sge;
871 	wr->opcode = IB_WR_SEND;
872 	wr->send_flags = IB_SEND_SIGNALED;
873 
874 	if (tx_desc->inv_wr.next)
875 		first_wr = &tx_desc->inv_wr;
876 	else if (tx_desc->reg_wr.wr.next)
877 		first_wr = &tx_desc->reg_wr.wr;
878 	else
879 		first_wr = wr;
880 
881 	ret = ib_post_send(ib_conn->qp, first_wr, NULL);
882 	if (unlikely(ret))
883 		iser_err("ib_post_send failed, ret:%d opcode:%d\n",
884 			 ret, wr->opcode);
885 
886 	return ret;
887 }
888 
iser_check_task_pi_status(struct iscsi_iser_task * iser_task,enum iser_data_dir cmd_dir,sector_t * sector)889 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
890 			     enum iser_data_dir cmd_dir, sector_t *sector)
891 {
892 	struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
893 	struct iser_fr_desc *desc = reg->desc;
894 	unsigned long sector_size = iser_task->sc->device->sector_size;
895 	struct ib_mr_status mr_status;
896 	int ret;
897 
898 	if (desc && desc->sig_protected) {
899 		desc->sig_protected = false;
900 		ret = ib_check_mr_status(desc->rsc.sig_mr,
901 					 IB_MR_CHECK_SIG_STATUS, &mr_status);
902 		if (ret) {
903 			iser_err("ib_check_mr_status failed, ret %d\n", ret);
904 			/* Not a lot we can do, return ambiguous guard error */
905 			*sector = 0;
906 			return 0x1;
907 		}
908 
909 		if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
910 			sector_t sector_off = mr_status.sig_err.sig_err_offset;
911 
912 			sector_div(sector_off, sector_size + 8);
913 			*sector = scsi_get_sector(iser_task->sc) + sector_off;
914 
915 			iser_err("PI error found type %d at sector %llx "
916 			       "expected %x vs actual %x\n",
917 			       mr_status.sig_err.err_type,
918 			       (unsigned long long)*sector,
919 			       mr_status.sig_err.expected,
920 			       mr_status.sig_err.actual);
921 
922 			switch (mr_status.sig_err.err_type) {
923 			case IB_SIG_BAD_GUARD:
924 				return 0x1;
925 			case IB_SIG_BAD_REFTAG:
926 				return 0x3;
927 			case IB_SIG_BAD_APPTAG:
928 				return 0x2;
929 			}
930 		}
931 	}
932 
933 	return 0;
934 }
935 
iser_err_comp(struct ib_wc * wc,const char * type)936 void iser_err_comp(struct ib_wc *wc, const char *type)
937 {
938 	if (wc->status != IB_WC_WR_FLUSH_ERR) {
939 		struct iser_conn *iser_conn = to_iser_conn(wc->qp->qp_context);
940 
941 		iser_err("%s failure: %s (%d) vend_err %#x\n", type,
942 			 ib_wc_status_msg(wc->status), wc->status,
943 			 wc->vendor_err);
944 
945 		if (iser_conn->iscsi_conn)
946 			iscsi_conn_failure(iser_conn->iscsi_conn,
947 					   ISCSI_ERR_CONN_FAILED);
948 	} else {
949 		iser_dbg("%s failure: %s (%d)\n", type,
950 			 ib_wc_status_msg(wc->status), wc->status);
951 	}
952 }
953