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
47static 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
53static 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 adaptor.
65 *
66 * Return: 0 on success, -1 on failure
67 */
68static int iser_create_device_ib_res(struct iser_device *device)
69{
70	struct ib_device *ib_dev = device->ib_device;
71
72	if (!(ib_dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS)) {
73		iser_err("IB device does not support memory registrations\n");
74		return -1;
75	}
76
77	device->pd = ib_alloc_pd(ib_dev,
78		iser_always_reg ? 0 : IB_PD_UNSAFE_GLOBAL_RKEY);
79	if (IS_ERR(device->pd))
80		goto pd_err;
81
82	INIT_IB_EVENT_HANDLER(&device->event_handler, ib_dev,
83			      iser_event_handler);
84	ib_register_event_handler(&device->event_handler);
85	return 0;
86
87pd_err:
88	iser_err("failed to allocate an IB resource\n");
89	return -1;
90}
91
92/*
93 * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
94 * CQ and PD created with the device associated with the adaptor.
95 */
96static void iser_free_device_ib_res(struct iser_device *device)
97{
98	ib_unregister_event_handler(&device->event_handler);
99	ib_dealloc_pd(device->pd);
100
101	device->pd = NULL;
102}
103
104static struct iser_fr_desc *
105iser_create_fastreg_desc(struct iser_device *device,
106			 struct ib_pd *pd,
107			 bool pi_enable,
108			 unsigned int size)
109{
110	struct iser_fr_desc *desc;
111	struct ib_device *ib_dev = device->ib_device;
112	enum ib_mr_type mr_type;
113	int ret;
114
115	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
116	if (!desc)
117		return ERR_PTR(-ENOMEM);
118
119	if (ib_dev->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG)
120		mr_type = IB_MR_TYPE_SG_GAPS;
121	else
122		mr_type = IB_MR_TYPE_MEM_REG;
123
124	desc->rsc.mr = ib_alloc_mr(pd, mr_type, size);
125	if (IS_ERR(desc->rsc.mr)) {
126		ret = PTR_ERR(desc->rsc.mr);
127		iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
128		goto err_alloc_mr;
129	}
130
131	if (pi_enable) {
132		desc->rsc.sig_mr = ib_alloc_mr_integrity(pd, size, size);
133		if (IS_ERR(desc->rsc.sig_mr)) {
134			ret = PTR_ERR(desc->rsc.sig_mr);
135			iser_err("Failed to allocate sig_mr err=%d\n", ret);
136			goto err_alloc_mr_integrity;
137		}
138	}
139
140	return desc;
141
142err_alloc_mr_integrity:
143	ib_dereg_mr(desc->rsc.mr);
144err_alloc_mr:
145	kfree(desc);
146
147	return ERR_PTR(ret);
148}
149
150static void iser_destroy_fastreg_desc(struct iser_fr_desc *desc)
151{
152	struct iser_reg_resources *res = &desc->rsc;
153
154	ib_dereg_mr(res->mr);
155	if (res->sig_mr) {
156		ib_dereg_mr(res->sig_mr);
157		res->sig_mr = NULL;
158	}
159	kfree(desc);
160}
161
162/**
163 * iser_alloc_fastreg_pool - Creates pool of fast_reg descriptors
164 * for fast registration work requests.
165 * @ib_conn: connection RDMA resources
166 * @cmds_max: max number of SCSI commands for this connection
167 * @size: max number of pages per map request
168 *
169 * Return: 0 on success, or errno code on failure
170 */
171int iser_alloc_fastreg_pool(struct ib_conn *ib_conn,
172			    unsigned cmds_max,
173			    unsigned int size)
174{
175	struct iser_device *device = ib_conn->device;
176	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
177	struct iser_fr_desc *desc;
178	int i, ret;
179
180	INIT_LIST_HEAD(&fr_pool->list);
181	INIT_LIST_HEAD(&fr_pool->all_list);
182	spin_lock_init(&fr_pool->lock);
183	fr_pool->size = 0;
184	for (i = 0; i < cmds_max; i++) {
185		desc = iser_create_fastreg_desc(device, device->pd,
186						ib_conn->pi_support, size);
187		if (IS_ERR(desc)) {
188			ret = PTR_ERR(desc);
189			goto err;
190		}
191
192		list_add_tail(&desc->list, &fr_pool->list);
193		list_add_tail(&desc->all_list, &fr_pool->all_list);
194		fr_pool->size++;
195	}
196
197	return 0;
198
199err:
200	iser_free_fastreg_pool(ib_conn);
201	return ret;
202}
203
204/**
205 * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
206 * @ib_conn: connection RDMA resources
207 */
208void iser_free_fastreg_pool(struct ib_conn *ib_conn)
209{
210	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
211	struct iser_fr_desc *desc, *tmp;
212	int i = 0;
213
214	if (list_empty(&fr_pool->all_list))
215		return;
216
217	iser_info("freeing conn %p fr pool\n", ib_conn);
218
219	list_for_each_entry_safe(desc, tmp, &fr_pool->all_list, all_list) {
220		list_del(&desc->all_list);
221		iser_destroy_fastreg_desc(desc);
222		++i;
223	}
224
225	if (i < fr_pool->size)
226		iser_warn("pool still has %d regions registered\n",
227			  fr_pool->size - i);
228}
229
230/*
231 * iser_create_ib_conn_res - Queue-Pair (QP)
232 *
233 * Return: 0 on success, -1 on failure
234 */
235static int iser_create_ib_conn_res(struct ib_conn *ib_conn)
236{
237	struct iser_conn *iser_conn = to_iser_conn(ib_conn);
238	struct iser_device	*device;
239	struct ib_device	*ib_dev;
240	struct ib_qp_init_attr	init_attr;
241	int			ret = -ENOMEM;
242	unsigned int max_send_wr, cq_size;
243
244	BUG_ON(ib_conn->device == NULL);
245
246	device = ib_conn->device;
247	ib_dev = device->ib_device;
248
249	if (ib_conn->pi_support)
250		max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS + 1;
251	else
252		max_send_wr = ISER_QP_MAX_REQ_DTOS + 1;
253	max_send_wr = min_t(unsigned int, max_send_wr,
254			    (unsigned int)ib_dev->attrs.max_qp_wr);
255
256	cq_size = max_send_wr + ISER_QP_MAX_RECV_DTOS;
257	ib_conn->cq = ib_cq_pool_get(ib_dev, cq_size, -1, IB_POLL_SOFTIRQ);
258	if (IS_ERR(ib_conn->cq)) {
259		ret = PTR_ERR(ib_conn->cq);
260		goto cq_err;
261	}
262	ib_conn->cq_size = cq_size;
263
264	memset(&init_attr, 0, sizeof(init_attr));
265
266	init_attr.event_handler = iser_qp_event_callback;
267	init_attr.qp_context	= (void *)ib_conn;
268	init_attr.send_cq	= ib_conn->cq;
269	init_attr.recv_cq	= ib_conn->cq;
270	init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
271	init_attr.cap.max_send_sge = 2;
272	init_attr.cap.max_recv_sge = 1;
273	init_attr.sq_sig_type	= IB_SIGNAL_REQ_WR;
274	init_attr.qp_type	= IB_QPT_RC;
275	init_attr.cap.max_send_wr = max_send_wr;
276	if (ib_conn->pi_support)
277		init_attr.create_flags |= IB_QP_CREATE_INTEGRITY_EN;
278	iser_conn->max_cmds = ISER_GET_MAX_XMIT_CMDS(max_send_wr - 1);
279
280	ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
281	if (ret)
282		goto out_err;
283
284	ib_conn->qp = ib_conn->cma_id->qp;
285	iser_info("setting conn %p cma_id %p qp %p max_send_wr %d\n",
286		  ib_conn, ib_conn->cma_id,
287		  ib_conn->cma_id->qp, max_send_wr);
288	return ret;
289
290out_err:
291	ib_cq_pool_put(ib_conn->cq, ib_conn->cq_size);
292cq_err:
293	iser_err("unable to alloc mem or create resource, err %d\n", ret);
294
295	return ret;
296}
297
298/*
299 * based on the resolved device node GUID see if there already allocated
300 * device for this device. If there's no such, create one.
301 */
302static
303struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
304{
305	struct iser_device *device;
306
307	mutex_lock(&ig.device_list_mutex);
308
309	list_for_each_entry(device, &ig.device_list, ig_list)
310		/* find if there's a match using the node GUID */
311		if (device->ib_device->node_guid == cma_id->device->node_guid)
312			goto inc_refcnt;
313
314	device = kzalloc(sizeof *device, GFP_KERNEL);
315	if (device == NULL)
316		goto out;
317
318	/* assign this device to the device */
319	device->ib_device = cma_id->device;
320	/* init the device and link it into ig device list */
321	if (iser_create_device_ib_res(device)) {
322		kfree(device);
323		device = NULL;
324		goto out;
325	}
326	list_add(&device->ig_list, &ig.device_list);
327
328inc_refcnt:
329	device->refcount++;
330out:
331	mutex_unlock(&ig.device_list_mutex);
332	return device;
333}
334
335/* if there's no demand for this device, release it */
336static void iser_device_try_release(struct iser_device *device)
337{
338	mutex_lock(&ig.device_list_mutex);
339	device->refcount--;
340	iser_info("device %p refcount %d\n", device, device->refcount);
341	if (!device->refcount) {
342		iser_free_device_ib_res(device);
343		list_del(&device->ig_list);
344		kfree(device);
345	}
346	mutex_unlock(&ig.device_list_mutex);
347}
348
349/*
350 * Called with state mutex held
351 */
352static int iser_conn_state_comp_exch(struct iser_conn *iser_conn,
353				     enum iser_conn_state comp,
354				     enum iser_conn_state exch)
355{
356	int ret;
357
358	ret = (iser_conn->state == comp);
359	if (ret)
360		iser_conn->state = exch;
361
362	return ret;
363}
364
365void iser_release_work(struct work_struct *work)
366{
367	struct iser_conn *iser_conn;
368
369	iser_conn = container_of(work, struct iser_conn, release_work);
370
371	/* Wait for conn_stop to complete */
372	wait_for_completion(&iser_conn->stop_completion);
373	/* Wait for IB resouces cleanup to complete */
374	wait_for_completion(&iser_conn->ib_completion);
375
376	mutex_lock(&iser_conn->state_mutex);
377	iser_conn->state = ISER_CONN_DOWN;
378	mutex_unlock(&iser_conn->state_mutex);
379
380	iser_conn_release(iser_conn);
381}
382
383/**
384 * iser_free_ib_conn_res - release IB related resources
385 * @iser_conn: iser connection struct
386 * @destroy: indicator if we need to try to release the
387 *     iser device and memory regoins pool (only iscsi
388 *     shutdown and DEVICE_REMOVAL will use this).
389 *
390 * This routine is called with the iser state mutex held
391 * so the cm_id removal is out of here. It is Safe to
392 * be invoked multiple times.
393 */
394static void iser_free_ib_conn_res(struct iser_conn *iser_conn,
395				  bool destroy)
396{
397	struct ib_conn *ib_conn = &iser_conn->ib_conn;
398	struct iser_device *device = ib_conn->device;
399
400	iser_info("freeing conn %p cma_id %p qp %p\n",
401		  iser_conn, ib_conn->cma_id, ib_conn->qp);
402
403	if (ib_conn->qp != NULL) {
404		rdma_destroy_qp(ib_conn->cma_id);
405		ib_cq_pool_put(ib_conn->cq, ib_conn->cq_size);
406		ib_conn->qp = NULL;
407	}
408
409	if (destroy) {
410		if (iser_conn->rx_descs)
411			iser_free_rx_descriptors(iser_conn);
412
413		if (device != NULL) {
414			iser_device_try_release(device);
415			ib_conn->device = NULL;
416		}
417	}
418}
419
420/**
421 * iser_conn_release - Frees all conn objects and deallocs conn descriptor
422 * @iser_conn: iSER connection context
423 */
424void iser_conn_release(struct iser_conn *iser_conn)
425{
426	struct ib_conn *ib_conn = &iser_conn->ib_conn;
427
428	mutex_lock(&ig.connlist_mutex);
429	list_del(&iser_conn->conn_list);
430	mutex_unlock(&ig.connlist_mutex);
431
432	mutex_lock(&iser_conn->state_mutex);
433	/* In case we endup here without ep_disconnect being invoked. */
434	if (iser_conn->state != ISER_CONN_DOWN) {
435		iser_warn("iser conn %p state %d, expected state down.\n",
436			  iser_conn, iser_conn->state);
437		iscsi_destroy_endpoint(iser_conn->ep);
438		iser_conn->state = ISER_CONN_DOWN;
439	}
440	/*
441	 * In case we never got to bind stage, we still need to
442	 * release IB resources (which is safe to call more than once).
443	 */
444	iser_free_ib_conn_res(iser_conn, true);
445	mutex_unlock(&iser_conn->state_mutex);
446
447	if (ib_conn->cma_id != NULL) {
448		rdma_destroy_id(ib_conn->cma_id);
449		ib_conn->cma_id = NULL;
450	}
451
452	kfree(iser_conn);
453}
454
455/**
456 * iser_conn_terminate - triggers start of the disconnect procedures and
457 * waits for them to be done
458 * @iser_conn: iSER connection context
459 *
460 * Called with state mutex held
461 */
462int iser_conn_terminate(struct iser_conn *iser_conn)
463{
464	struct ib_conn *ib_conn = &iser_conn->ib_conn;
465	int err = 0;
466
467	/* terminate the iser conn only if the conn state is UP */
468	if (!iser_conn_state_comp_exch(iser_conn, ISER_CONN_UP,
469				       ISER_CONN_TERMINATING))
470		return 0;
471
472	iser_info("iser_conn %p state %d\n", iser_conn, iser_conn->state);
473
474	/* suspend queuing of new iscsi commands */
475	if (iser_conn->iscsi_conn)
476		iscsi_suspend_queue(iser_conn->iscsi_conn);
477
478	/*
479	 * In case we didn't already clean up the cma_id (peer initiated
480	 * a disconnection), we need to Cause the CMA to change the QP
481	 * state to ERROR.
482	 */
483	if (ib_conn->cma_id) {
484		err = rdma_disconnect(ib_conn->cma_id);
485		if (err)
486			iser_err("Failed to disconnect, conn: 0x%p err %d\n",
487				 iser_conn, err);
488
489		/* block until all flush errors are consumed */
490		ib_drain_sq(ib_conn->qp);
491	}
492
493	return 1;
494}
495
496/*
497 * Called with state mutex held
498 */
499static void iser_connect_error(struct rdma_cm_id *cma_id)
500{
501	struct iser_conn *iser_conn;
502
503	iser_conn = (struct iser_conn *)cma_id->context;
504	iser_conn->state = ISER_CONN_TERMINATING;
505}
506
507static void
508iser_calc_scsi_params(struct iser_conn *iser_conn,
509		      unsigned int max_sectors)
510{
511	struct iser_device *device = iser_conn->ib_conn.device;
512	struct ib_device_attr *attr = &device->ib_device->attrs;
513	unsigned short sg_tablesize, sup_sg_tablesize;
514	unsigned short reserved_mr_pages;
515	u32 max_num_sg;
516
517	/*
518	 * FRs without SG_GAPS can only map up to a (device) page per entry,
519	 * but if the first entry is misaligned we'll end up using two entries
520	 * (head and tail) for a single page worth data, so one additional
521	 * entry is required.
522	 */
523	if (attr->device_cap_flags & IB_DEVICE_SG_GAPS_REG)
524		reserved_mr_pages = 0;
525	else
526		reserved_mr_pages = 1;
527
528	if (iser_conn->ib_conn.pi_support)
529		max_num_sg = attr->max_pi_fast_reg_page_list_len;
530	else
531		max_num_sg = attr->max_fast_reg_page_list_len;
532
533	sg_tablesize = DIV_ROUND_UP(max_sectors * SECTOR_SIZE, SZ_4K);
534	sup_sg_tablesize = min_t(uint, ISCSI_ISER_MAX_SG_TABLESIZE,
535				 max_num_sg - reserved_mr_pages);
536	iser_conn->scsi_sg_tablesize = min(sg_tablesize, sup_sg_tablesize);
537	iser_conn->pages_per_mr =
538		iser_conn->scsi_sg_tablesize + reserved_mr_pages;
539}
540
541/*
542 * Called with state mutex held
543 */
544static void iser_addr_handler(struct rdma_cm_id *cma_id)
545{
546	struct iser_device *device;
547	struct iser_conn   *iser_conn;
548	struct ib_conn   *ib_conn;
549	int    ret;
550
551	iser_conn = (struct iser_conn *)cma_id->context;
552	if (iser_conn->state != ISER_CONN_PENDING)
553		/* bailout */
554		return;
555
556	ib_conn = &iser_conn->ib_conn;
557	device = iser_device_find_by_ib_device(cma_id);
558	if (!device) {
559		iser_err("device lookup/creation failed\n");
560		iser_connect_error(cma_id);
561		return;
562	}
563
564	ib_conn->device = device;
565
566	/* connection T10-PI support */
567	if (iser_pi_enable) {
568		if (!(device->ib_device->attrs.device_cap_flags &
569		      IB_DEVICE_INTEGRITY_HANDOVER)) {
570			iser_warn("T10-PI requested but not supported on %s, "
571				  "continue without T10-PI\n",
572				  dev_name(&ib_conn->device->ib_device->dev));
573			ib_conn->pi_support = false;
574		} else {
575			ib_conn->pi_support = true;
576		}
577	}
578
579	iser_calc_scsi_params(iser_conn, iser_max_sectors);
580
581	ret = rdma_resolve_route(cma_id, 1000);
582	if (ret) {
583		iser_err("resolve route failed: %d\n", ret);
584		iser_connect_error(cma_id);
585		return;
586	}
587}
588
589/*
590 * Called with state mutex held
591 */
592static void iser_route_handler(struct rdma_cm_id *cma_id)
593{
594	struct rdma_conn_param conn_param;
595	int    ret;
596	struct iser_cm_hdr req_hdr;
597	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
598	struct ib_conn *ib_conn = &iser_conn->ib_conn;
599	struct ib_device *ib_dev = ib_conn->device->ib_device;
600
601	if (iser_conn->state != ISER_CONN_PENDING)
602		/* bailout */
603		return;
604
605	ret = iser_create_ib_conn_res(ib_conn);
606	if (ret)
607		goto failure;
608
609	memset(&conn_param, 0, sizeof conn_param);
610	conn_param.responder_resources = ib_dev->attrs.max_qp_rd_atom;
611	conn_param.initiator_depth     = 1;
612	conn_param.retry_count	       = 7;
613	conn_param.rnr_retry_count     = 6;
614
615	memset(&req_hdr, 0, sizeof(req_hdr));
616	req_hdr.flags = ISER_ZBVA_NOT_SUP;
617	if (!iser_always_reg)
618		req_hdr.flags |= ISER_SEND_W_INV_NOT_SUP;
619	conn_param.private_data	= (void *)&req_hdr;
620	conn_param.private_data_len = sizeof(struct iser_cm_hdr);
621
622	ret = rdma_connect_locked(cma_id, &conn_param);
623	if (ret) {
624		iser_err("failure connecting: %d\n", ret);
625		goto failure;
626	}
627
628	return;
629failure:
630	iser_connect_error(cma_id);
631}
632
633static void iser_connected_handler(struct rdma_cm_id *cma_id,
634				   const void *private_data)
635{
636	struct iser_conn *iser_conn;
637	struct ib_qp_attr attr;
638	struct ib_qp_init_attr init_attr;
639
640	iser_conn = (struct iser_conn *)cma_id->context;
641	if (iser_conn->state != ISER_CONN_PENDING)
642		/* bailout */
643		return;
644
645	(void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
646	iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
647
648	if (private_data) {
649		u8 flags = *(u8 *)private_data;
650
651		iser_conn->snd_w_inv = !(flags & ISER_SEND_W_INV_NOT_SUP);
652	}
653
654	iser_info("conn %p: negotiated %s invalidation\n",
655		  iser_conn, iser_conn->snd_w_inv ? "remote" : "local");
656
657	iser_conn->state = ISER_CONN_UP;
658	complete(&iser_conn->up_completion);
659}
660
661static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
662{
663	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
664
665	if (iser_conn_terminate(iser_conn)) {
666		if (iser_conn->iscsi_conn)
667			iscsi_conn_failure(iser_conn->iscsi_conn,
668					   ISCSI_ERR_CONN_FAILED);
669		else
670			iser_err("iscsi_iser connection isn't bound\n");
671	}
672}
673
674static void iser_cleanup_handler(struct rdma_cm_id *cma_id,
675				 bool destroy)
676{
677	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
678
679	/*
680	 * We are not guaranteed that we visited disconnected_handler
681	 * by now, call it here to be safe that we handle CM drep
682	 * and flush errors.
683	 */
684	iser_disconnected_handler(cma_id);
685	iser_free_ib_conn_res(iser_conn, destroy);
686	complete(&iser_conn->ib_completion);
687};
688
689static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
690{
691	struct iser_conn *iser_conn;
692	int ret = 0;
693
694	iser_conn = (struct iser_conn *)cma_id->context;
695	iser_info("%s (%d): status %d conn %p id %p\n",
696		  rdma_event_msg(event->event), event->event,
697		  event->status, cma_id->context, cma_id);
698
699	mutex_lock(&iser_conn->state_mutex);
700	switch (event->event) {
701	case RDMA_CM_EVENT_ADDR_RESOLVED:
702		iser_addr_handler(cma_id);
703		break;
704	case RDMA_CM_EVENT_ROUTE_RESOLVED:
705		iser_route_handler(cma_id);
706		break;
707	case RDMA_CM_EVENT_ESTABLISHED:
708		iser_connected_handler(cma_id, event->param.conn.private_data);
709		break;
710	case RDMA_CM_EVENT_REJECTED:
711		iser_info("Connection rejected: %s\n",
712			 rdma_reject_msg(cma_id, event->status));
713		fallthrough;
714	case RDMA_CM_EVENT_ADDR_ERROR:
715	case RDMA_CM_EVENT_ROUTE_ERROR:
716	case RDMA_CM_EVENT_CONNECT_ERROR:
717	case RDMA_CM_EVENT_UNREACHABLE:
718		iser_connect_error(cma_id);
719		break;
720	case RDMA_CM_EVENT_DISCONNECTED:
721	case RDMA_CM_EVENT_ADDR_CHANGE:
722	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
723		iser_cleanup_handler(cma_id, false);
724		break;
725	case RDMA_CM_EVENT_DEVICE_REMOVAL:
726		/*
727		 * we *must* destroy the device as we cannot rely
728		 * on iscsid to be around to initiate error handling.
729		 * also if we are not in state DOWN implicitly destroy
730		 * the cma_id.
731		 */
732		iser_cleanup_handler(cma_id, true);
733		if (iser_conn->state != ISER_CONN_DOWN) {
734			iser_conn->ib_conn.cma_id = NULL;
735			ret = 1;
736		}
737		break;
738	default:
739		iser_err("Unexpected RDMA CM event: %s (%d)\n",
740			 rdma_event_msg(event->event), event->event);
741		break;
742	}
743	mutex_unlock(&iser_conn->state_mutex);
744
745	return ret;
746}
747
748void iser_conn_init(struct iser_conn *iser_conn)
749{
750	struct ib_conn *ib_conn = &iser_conn->ib_conn;
751
752	iser_conn->state = ISER_CONN_INIT;
753	init_completion(&iser_conn->stop_completion);
754	init_completion(&iser_conn->ib_completion);
755	init_completion(&iser_conn->up_completion);
756	INIT_LIST_HEAD(&iser_conn->conn_list);
757	mutex_init(&iser_conn->state_mutex);
758
759	ib_conn->post_recv_buf_count = 0;
760	ib_conn->reg_cqe.done = iser_reg_comp;
761}
762
763 /**
764 * starts the process of connecting to the target
765 * sleeps until the connection is established or rejected
766 */
767int iser_connect(struct iser_conn   *iser_conn,
768		 struct sockaddr    *src_addr,
769		 struct sockaddr    *dst_addr,
770		 int                 non_blocking)
771{
772	struct ib_conn *ib_conn = &iser_conn->ib_conn;
773	int err = 0;
774
775	mutex_lock(&iser_conn->state_mutex);
776
777	sprintf(iser_conn->name, "%pISp", dst_addr);
778
779	iser_info("connecting to: %s\n", iser_conn->name);
780
781	/* the device is known only --after-- address resolution */
782	ib_conn->device = NULL;
783
784	iser_conn->state = ISER_CONN_PENDING;
785
786	ib_conn->cma_id = rdma_create_id(&init_net, iser_cma_handler,
787					 (void *)iser_conn,
788					 RDMA_PS_TCP, IB_QPT_RC);
789	if (IS_ERR(ib_conn->cma_id)) {
790		err = PTR_ERR(ib_conn->cma_id);
791		iser_err("rdma_create_id failed: %d\n", err);
792		goto id_failure;
793	}
794
795	err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
796	if (err) {
797		iser_err("rdma_resolve_addr failed: %d\n", err);
798		goto addr_failure;
799	}
800
801	if (!non_blocking) {
802		wait_for_completion_interruptible(&iser_conn->up_completion);
803
804		if (iser_conn->state != ISER_CONN_UP) {
805			err =  -EIO;
806			goto connect_failure;
807		}
808	}
809	mutex_unlock(&iser_conn->state_mutex);
810
811	mutex_lock(&ig.connlist_mutex);
812	list_add(&iser_conn->conn_list, &ig.connlist);
813	mutex_unlock(&ig.connlist_mutex);
814	return 0;
815
816id_failure:
817	ib_conn->cma_id = NULL;
818addr_failure:
819	iser_conn->state = ISER_CONN_DOWN;
820connect_failure:
821	mutex_unlock(&iser_conn->state_mutex);
822	iser_conn_release(iser_conn);
823	return err;
824}
825
826int iser_post_recvl(struct iser_conn *iser_conn)
827{
828	struct ib_conn *ib_conn = &iser_conn->ib_conn;
829	struct iser_login_desc *desc = &iser_conn->login_desc;
830	struct ib_recv_wr wr;
831	int ib_ret;
832
833	desc->sge.addr = desc->rsp_dma;
834	desc->sge.length = ISER_RX_LOGIN_SIZE;
835	desc->sge.lkey = ib_conn->device->pd->local_dma_lkey;
836
837	desc->cqe.done = iser_login_rsp;
838	wr.wr_cqe = &desc->cqe;
839	wr.sg_list = &desc->sge;
840	wr.num_sge = 1;
841	wr.next = NULL;
842
843	ib_conn->post_recv_buf_count++;
844	ib_ret = ib_post_recv(ib_conn->qp, &wr, NULL);
845	if (ib_ret) {
846		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
847		ib_conn->post_recv_buf_count--;
848	}
849
850	return ib_ret;
851}
852
853int iser_post_recvm(struct iser_conn *iser_conn, int count)
854{
855	struct ib_conn *ib_conn = &iser_conn->ib_conn;
856	unsigned int my_rx_head = iser_conn->rx_desc_head;
857	struct iser_rx_desc *rx_desc;
858	struct ib_recv_wr *wr;
859	int i, ib_ret;
860
861	for (wr = ib_conn->rx_wr, i = 0; i < count; i++, wr++) {
862		rx_desc = &iser_conn->rx_descs[my_rx_head];
863		rx_desc->cqe.done = iser_task_rsp;
864		wr->wr_cqe = &rx_desc->cqe;
865		wr->sg_list = &rx_desc->rx_sg;
866		wr->num_sge = 1;
867		wr->next = wr + 1;
868		my_rx_head = (my_rx_head + 1) & iser_conn->qp_max_recv_dtos_mask;
869	}
870
871	wr--;
872	wr->next = NULL; /* mark end of work requests list */
873
874	ib_conn->post_recv_buf_count += count;
875	ib_ret = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, NULL);
876	if (unlikely(ib_ret)) {
877		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
878		ib_conn->post_recv_buf_count -= count;
879	} else
880		iser_conn->rx_desc_head = my_rx_head;
881
882	return ib_ret;
883}
884
885
886/**
887 * iser_post_send - Initiate a Send DTO operation
888 * @ib_conn: connection RDMA resources
889 * @tx_desc: iSER TX descriptor
890 * @signal: true to send work request as SIGNALED
891 *
892 * Return: 0 on success, -1 on failure
893 */
894int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
895		   bool signal)
896{
897	struct ib_send_wr *wr = &tx_desc->send_wr;
898	struct ib_send_wr *first_wr;
899	int ib_ret;
900
901	ib_dma_sync_single_for_device(ib_conn->device->ib_device,
902				      tx_desc->dma_addr, ISER_HEADERS_LEN,
903				      DMA_TO_DEVICE);
904
905	wr->next = NULL;
906	wr->wr_cqe = &tx_desc->cqe;
907	wr->sg_list = tx_desc->tx_sg;
908	wr->num_sge = tx_desc->num_sge;
909	wr->opcode = IB_WR_SEND;
910	wr->send_flags = signal ? IB_SEND_SIGNALED : 0;
911
912	if (tx_desc->inv_wr.next)
913		first_wr = &tx_desc->inv_wr;
914	else if (tx_desc->reg_wr.wr.next)
915		first_wr = &tx_desc->reg_wr.wr;
916	else
917		first_wr = wr;
918
919	ib_ret = ib_post_send(ib_conn->qp, first_wr, NULL);
920	if (unlikely(ib_ret))
921		iser_err("ib_post_send failed, ret:%d opcode:%d\n",
922			 ib_ret, wr->opcode);
923
924	return ib_ret;
925}
926
927u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
928			     enum iser_data_dir cmd_dir, sector_t *sector)
929{
930	struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
931	struct iser_fr_desc *desc = reg->mem_h;
932	unsigned long sector_size = iser_task->sc->device->sector_size;
933	struct ib_mr_status mr_status;
934	int ret;
935
936	if (desc && desc->sig_protected) {
937		desc->sig_protected = false;
938		ret = ib_check_mr_status(desc->rsc.sig_mr,
939					 IB_MR_CHECK_SIG_STATUS, &mr_status);
940		if (ret) {
941			iser_err("ib_check_mr_status failed, ret %d\n", ret);
942			/* Not a lot we can do, return ambiguous guard error */
943			*sector = 0;
944			return 0x1;
945		}
946
947		if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
948			sector_t sector_off = mr_status.sig_err.sig_err_offset;
949
950			sector_div(sector_off, sector_size + 8);
951			*sector = scsi_get_lba(iser_task->sc) + sector_off;
952
953			iser_err("PI error found type %d at sector %llx "
954			       "expected %x vs actual %x\n",
955			       mr_status.sig_err.err_type,
956			       (unsigned long long)*sector,
957			       mr_status.sig_err.expected,
958			       mr_status.sig_err.actual);
959
960			switch (mr_status.sig_err.err_type) {
961			case IB_SIG_BAD_GUARD:
962				return 0x1;
963			case IB_SIG_BAD_REFTAG:
964				return 0x3;
965			case IB_SIG_BAD_APPTAG:
966				return 0x2;
967			}
968		}
969	}
970
971	return 0;
972}
973
974void iser_err_comp(struct ib_wc *wc, const char *type)
975{
976	if (wc->status != IB_WC_WR_FLUSH_ERR) {
977		struct iser_conn *iser_conn = to_iser_conn(wc->qp->qp_context);
978
979		iser_err("%s failure: %s (%d) vend_err %#x\n", type,
980			 ib_wc_status_msg(wc->status), wc->status,
981			 wc->vendor_err);
982
983		if (iser_conn->iscsi_conn)
984			iscsi_conn_failure(iser_conn->iscsi_conn,
985					   ISCSI_ERR_CONN_FAILED);
986	} else {
987		iser_dbg("%s failure: %s (%d)\n", type,
988			 ib_wc_status_msg(wc->status), wc->status);
989	}
990}
991