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 int iser_cq_poll_limit = 512;
48 
49 static void iser_cq_tasklet_fn(unsigned long data);
50 static void iser_cq_callback(struct ib_cq *cq, void *cq_context);
51 
52 static void iser_cq_event_callback(struct ib_event *cause, void *context)
53 {
54 	iser_err("got cq event %d \n", cause->event);
55 }
56 
57 static void iser_qp_event_callback(struct ib_event *cause, void *context)
58 {
59 	iser_err("got qp event %d\n",cause->event);
60 }
61 
62 static void iser_event_handler(struct ib_event_handler *handler,
63 				struct ib_event *event)
64 {
65 	iser_err("async event %d on device %s port %d\n", event->event,
66 		event->device->name, event->element.port_num);
67 }
68 
69 /**
70  * iser_create_device_ib_res - creates Protection Domain (PD), Completion
71  * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
72  * the adapator.
73  *
74  * returns 0 on success, -1 on failure
75  */
76 static int iser_create_device_ib_res(struct iser_device *device)
77 {
78 	struct ib_device_attr *dev_attr = &device->dev_attr;
79 	int ret, i, max_cqe;
80 
81 	ret = ib_query_device(device->ib_device, dev_attr);
82 	if (ret) {
83 		pr_warn("Query device failed for %s\n", device->ib_device->name);
84 		return ret;
85 	}
86 
87 	/* Assign function handles  - based on FMR support */
88 	if (device->ib_device->alloc_fmr && device->ib_device->dealloc_fmr &&
89 	    device->ib_device->map_phys_fmr && device->ib_device->unmap_fmr) {
90 		iser_info("FMR supported, using FMR for registration\n");
91 		device->iser_alloc_rdma_reg_res = iser_create_fmr_pool;
92 		device->iser_free_rdma_reg_res = iser_free_fmr_pool;
93 		device->iser_reg_rdma_mem = iser_reg_rdma_mem_fmr;
94 		device->iser_unreg_rdma_mem = iser_unreg_mem_fmr;
95 	} else
96 	if (dev_attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
97 		iser_info("FastReg supported, using FastReg for registration\n");
98 		device->iser_alloc_rdma_reg_res = iser_create_fastreg_pool;
99 		device->iser_free_rdma_reg_res = iser_free_fastreg_pool;
100 		device->iser_reg_rdma_mem = iser_reg_rdma_mem_fastreg;
101 		device->iser_unreg_rdma_mem = iser_unreg_mem_fastreg;
102 	} else {
103 		iser_err("IB device does not support FMRs nor FastRegs, can't register memory\n");
104 		return -1;
105 	}
106 
107 	device->comps_used = min_t(int, num_online_cpus(),
108 				 device->ib_device->num_comp_vectors);
109 
110 	device->comps = kcalloc(device->comps_used, sizeof(*device->comps),
111 				GFP_KERNEL);
112 	if (!device->comps)
113 		goto comps_err;
114 
115 	max_cqe = min(ISER_MAX_CQ_LEN, dev_attr->max_cqe);
116 
117 	iser_info("using %d CQs, device %s supports %d vectors max_cqe %d\n",
118 		  device->comps_used, device->ib_device->name,
119 		  device->ib_device->num_comp_vectors, max_cqe);
120 
121 	device->pd = ib_alloc_pd(device->ib_device);
122 	if (IS_ERR(device->pd))
123 		goto pd_err;
124 
125 	for (i = 0; i < device->comps_used; i++) {
126 		struct iser_comp *comp = &device->comps[i];
127 
128 		comp->device = device;
129 		comp->cq = ib_create_cq(device->ib_device,
130 					iser_cq_callback,
131 					iser_cq_event_callback,
132 					(void *)comp,
133 					max_cqe, i);
134 		if (IS_ERR(comp->cq)) {
135 			comp->cq = NULL;
136 			goto cq_err;
137 		}
138 
139 		if (ib_req_notify_cq(comp->cq, IB_CQ_NEXT_COMP))
140 			goto cq_err;
141 
142 		tasklet_init(&comp->tasklet, iser_cq_tasklet_fn,
143 			     (unsigned long)comp);
144 	}
145 
146 	device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
147 				   IB_ACCESS_REMOTE_WRITE |
148 				   IB_ACCESS_REMOTE_READ);
149 	if (IS_ERR(device->mr))
150 		goto dma_mr_err;
151 
152 	INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
153 				iser_event_handler);
154 	if (ib_register_event_handler(&device->event_handler))
155 		goto handler_err;
156 
157 	return 0;
158 
159 handler_err:
160 	ib_dereg_mr(device->mr);
161 dma_mr_err:
162 	for (i = 0; i < device->comps_used; i++)
163 		tasklet_kill(&device->comps[i].tasklet);
164 cq_err:
165 	for (i = 0; i < device->comps_used; i++) {
166 		struct iser_comp *comp = &device->comps[i];
167 
168 		if (comp->cq)
169 			ib_destroy_cq(comp->cq);
170 	}
171 	ib_dealloc_pd(device->pd);
172 pd_err:
173 	kfree(device->comps);
174 comps_err:
175 	iser_err("failed to allocate an IB resource\n");
176 	return -1;
177 }
178 
179 /**
180  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
181  * CQ and PD created with the device associated with the adapator.
182  */
183 static void iser_free_device_ib_res(struct iser_device *device)
184 {
185 	int i;
186 	BUG_ON(device->mr == NULL);
187 
188 	for (i = 0; i < device->comps_used; i++) {
189 		struct iser_comp *comp = &device->comps[i];
190 
191 		tasklet_kill(&comp->tasklet);
192 		ib_destroy_cq(comp->cq);
193 		comp->cq = NULL;
194 	}
195 
196 	(void)ib_unregister_event_handler(&device->event_handler);
197 	(void)ib_dereg_mr(device->mr);
198 	(void)ib_dealloc_pd(device->pd);
199 
200 	kfree(device->comps);
201 	device->comps = NULL;
202 
203 	device->mr = NULL;
204 	device->pd = NULL;
205 }
206 
207 /**
208  * iser_create_fmr_pool - Creates FMR pool and page_vector
209  *
210  * returns 0 on success, or errno code on failure
211  */
212 int iser_create_fmr_pool(struct ib_conn *ib_conn, unsigned cmds_max)
213 {
214 	struct iser_device *device = ib_conn->device;
215 	struct ib_fmr_pool_param params;
216 	int ret = -ENOMEM;
217 
218 	ib_conn->fmr.page_vec = kmalloc(sizeof(*ib_conn->fmr.page_vec) +
219 					(sizeof(u64)*(ISCSI_ISER_SG_TABLESIZE + 1)),
220 					GFP_KERNEL);
221 	if (!ib_conn->fmr.page_vec)
222 		return ret;
223 
224 	ib_conn->fmr.page_vec->pages = (u64 *)(ib_conn->fmr.page_vec + 1);
225 
226 	params.page_shift        = SHIFT_4K;
227 	/* when the first/last SG element are not start/end *
228 	 * page aligned, the map whould be of N+1 pages     */
229 	params.max_pages_per_fmr = ISCSI_ISER_SG_TABLESIZE + 1;
230 	/* make the pool size twice the max number of SCSI commands *
231 	 * the ML is expected to queue, watermark for unmap at 50%  */
232 	params.pool_size	 = cmds_max * 2;
233 	params.dirty_watermark	 = cmds_max;
234 	params.cache		 = 0;
235 	params.flush_function	 = NULL;
236 	params.access		 = (IB_ACCESS_LOCAL_WRITE  |
237 				    IB_ACCESS_REMOTE_WRITE |
238 				    IB_ACCESS_REMOTE_READ);
239 
240 	ib_conn->fmr.pool = ib_create_fmr_pool(device->pd, &params);
241 	if (!IS_ERR(ib_conn->fmr.pool))
242 		return 0;
243 
244 	/* no FMR => no need for page_vec */
245 	kfree(ib_conn->fmr.page_vec);
246 	ib_conn->fmr.page_vec = NULL;
247 
248 	ret = PTR_ERR(ib_conn->fmr.pool);
249 	ib_conn->fmr.pool = NULL;
250 	if (ret != -ENOSYS) {
251 		iser_err("FMR allocation failed, err %d\n", ret);
252 		return ret;
253 	} else {
254 		iser_warn("FMRs are not supported, using unaligned mode\n");
255 		return 0;
256 	}
257 }
258 
259 /**
260  * iser_free_fmr_pool - releases the FMR pool and page vec
261  */
262 void iser_free_fmr_pool(struct ib_conn *ib_conn)
263 {
264 	iser_info("freeing conn %p fmr pool %p\n",
265 		  ib_conn, ib_conn->fmr.pool);
266 
267 	if (ib_conn->fmr.pool != NULL)
268 		ib_destroy_fmr_pool(ib_conn->fmr.pool);
269 
270 	ib_conn->fmr.pool = NULL;
271 
272 	kfree(ib_conn->fmr.page_vec);
273 	ib_conn->fmr.page_vec = NULL;
274 }
275 
276 static int
277 iser_alloc_pi_ctx(struct ib_device *ib_device, struct ib_pd *pd,
278 		  struct fast_reg_descriptor *desc)
279 {
280 	struct iser_pi_context *pi_ctx = NULL;
281 	struct ib_mr_init_attr mr_init_attr = {.max_reg_descriptors = 2,
282 					       .flags = IB_MR_SIGNATURE_EN};
283 	int ret = 0;
284 
285 	desc->pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
286 	if (!desc->pi_ctx)
287 		return -ENOMEM;
288 
289 	pi_ctx = desc->pi_ctx;
290 
291 	pi_ctx->prot_frpl = ib_alloc_fast_reg_page_list(ib_device,
292 					    ISCSI_ISER_SG_TABLESIZE);
293 	if (IS_ERR(pi_ctx->prot_frpl)) {
294 		ret = PTR_ERR(pi_ctx->prot_frpl);
295 		goto prot_frpl_failure;
296 	}
297 
298 	pi_ctx->prot_mr = ib_alloc_fast_reg_mr(pd,
299 					ISCSI_ISER_SG_TABLESIZE + 1);
300 	if (IS_ERR(pi_ctx->prot_mr)) {
301 		ret = PTR_ERR(pi_ctx->prot_mr);
302 		goto prot_mr_failure;
303 	}
304 	desc->reg_indicators |= ISER_PROT_KEY_VALID;
305 
306 	pi_ctx->sig_mr = ib_create_mr(pd, &mr_init_attr);
307 	if (IS_ERR(pi_ctx->sig_mr)) {
308 		ret = PTR_ERR(pi_ctx->sig_mr);
309 		goto sig_mr_failure;
310 	}
311 	desc->reg_indicators |= ISER_SIG_KEY_VALID;
312 	desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
313 
314 	return 0;
315 
316 sig_mr_failure:
317 	ib_dereg_mr(desc->pi_ctx->prot_mr);
318 prot_mr_failure:
319 	ib_free_fast_reg_page_list(desc->pi_ctx->prot_frpl);
320 prot_frpl_failure:
321 	kfree(desc->pi_ctx);
322 
323 	return ret;
324 }
325 
326 static void
327 iser_free_pi_ctx(struct iser_pi_context *pi_ctx)
328 {
329 	ib_free_fast_reg_page_list(pi_ctx->prot_frpl);
330 	ib_dereg_mr(pi_ctx->prot_mr);
331 	ib_destroy_mr(pi_ctx->sig_mr);
332 	kfree(pi_ctx);
333 }
334 
335 static int
336 iser_create_fastreg_desc(struct ib_device *ib_device, struct ib_pd *pd,
337 			 bool pi_enable, struct fast_reg_descriptor *desc)
338 {
339 	int ret;
340 
341 	desc->data_frpl = ib_alloc_fast_reg_page_list(ib_device,
342 						      ISCSI_ISER_SG_TABLESIZE + 1);
343 	if (IS_ERR(desc->data_frpl)) {
344 		ret = PTR_ERR(desc->data_frpl);
345 		iser_err("Failed to allocate ib_fast_reg_page_list err=%d\n",
346 			 ret);
347 		return PTR_ERR(desc->data_frpl);
348 	}
349 
350 	desc->data_mr = ib_alloc_fast_reg_mr(pd, ISCSI_ISER_SG_TABLESIZE + 1);
351 	if (IS_ERR(desc->data_mr)) {
352 		ret = PTR_ERR(desc->data_mr);
353 		iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
354 		goto fast_reg_mr_failure;
355 	}
356 	desc->reg_indicators |= ISER_DATA_KEY_VALID;
357 
358 	if (pi_enable) {
359 		ret = iser_alloc_pi_ctx(ib_device, pd, desc);
360 		if (ret)
361 			goto pi_ctx_alloc_failure;
362 	}
363 
364 	return 0;
365 pi_ctx_alloc_failure:
366 	ib_dereg_mr(desc->data_mr);
367 fast_reg_mr_failure:
368 	ib_free_fast_reg_page_list(desc->data_frpl);
369 
370 	return ret;
371 }
372 
373 /**
374  * iser_create_fastreg_pool - Creates pool of fast_reg descriptors
375  * for fast registration work requests.
376  * returns 0 on success, or errno code on failure
377  */
378 int iser_create_fastreg_pool(struct ib_conn *ib_conn, unsigned cmds_max)
379 {
380 	struct iser_device *device = ib_conn->device;
381 	struct fast_reg_descriptor *desc;
382 	int i, ret;
383 
384 	INIT_LIST_HEAD(&ib_conn->fastreg.pool);
385 	ib_conn->fastreg.pool_size = 0;
386 	for (i = 0; i < cmds_max; i++) {
387 		desc = kzalloc(sizeof(*desc), GFP_KERNEL);
388 		if (!desc) {
389 			iser_err("Failed to allocate a new fast_reg descriptor\n");
390 			ret = -ENOMEM;
391 			goto err;
392 		}
393 
394 		ret = iser_create_fastreg_desc(device->ib_device, device->pd,
395 					       ib_conn->pi_support, desc);
396 		if (ret) {
397 			iser_err("Failed to create fastreg descriptor err=%d\n",
398 				 ret);
399 			kfree(desc);
400 			goto err;
401 		}
402 
403 		list_add_tail(&desc->list, &ib_conn->fastreg.pool);
404 		ib_conn->fastreg.pool_size++;
405 	}
406 
407 	return 0;
408 
409 err:
410 	iser_free_fastreg_pool(ib_conn);
411 	return ret;
412 }
413 
414 /**
415  * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
416  */
417 void iser_free_fastreg_pool(struct ib_conn *ib_conn)
418 {
419 	struct fast_reg_descriptor *desc, *tmp;
420 	int i = 0;
421 
422 	if (list_empty(&ib_conn->fastreg.pool))
423 		return;
424 
425 	iser_info("freeing conn %p fr pool\n", ib_conn);
426 
427 	list_for_each_entry_safe(desc, tmp, &ib_conn->fastreg.pool, list) {
428 		list_del(&desc->list);
429 		ib_free_fast_reg_page_list(desc->data_frpl);
430 		ib_dereg_mr(desc->data_mr);
431 		if (desc->pi_ctx)
432 			iser_free_pi_ctx(desc->pi_ctx);
433 		kfree(desc);
434 		++i;
435 	}
436 
437 	if (i < ib_conn->fastreg.pool_size)
438 		iser_warn("pool still has %d regions registered\n",
439 			  ib_conn->fastreg.pool_size - i);
440 }
441 
442 /**
443  * iser_create_ib_conn_res - Queue-Pair (QP)
444  *
445  * returns 0 on success, -1 on failure
446  */
447 static int iser_create_ib_conn_res(struct ib_conn *ib_conn)
448 {
449 	struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
450 						   ib_conn);
451 	struct iser_device	*device;
452 	struct ib_device_attr *dev_attr;
453 	struct ib_qp_init_attr	init_attr;
454 	int			ret = -ENOMEM;
455 	int index, min_index = 0;
456 
457 	BUG_ON(ib_conn->device == NULL);
458 
459 	device = ib_conn->device;
460 	dev_attr = &device->dev_attr;
461 
462 	memset(&init_attr, 0, sizeof init_attr);
463 
464 	mutex_lock(&ig.connlist_mutex);
465 	/* select the CQ with the minimal number of usages */
466 	for (index = 0; index < device->comps_used; index++) {
467 		if (device->comps[index].active_qps <
468 		    device->comps[min_index].active_qps)
469 			min_index = index;
470 	}
471 	ib_conn->comp = &device->comps[min_index];
472 	ib_conn->comp->active_qps++;
473 	mutex_unlock(&ig.connlist_mutex);
474 	iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
475 
476 	init_attr.event_handler = iser_qp_event_callback;
477 	init_attr.qp_context	= (void *)ib_conn;
478 	init_attr.send_cq	= ib_conn->comp->cq;
479 	init_attr.recv_cq	= ib_conn->comp->cq;
480 	init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
481 	init_attr.cap.max_send_sge = 2;
482 	init_attr.cap.max_recv_sge = 1;
483 	init_attr.sq_sig_type	= IB_SIGNAL_REQ_WR;
484 	init_attr.qp_type	= IB_QPT_RC;
485 	if (ib_conn->pi_support) {
486 		init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS + 1;
487 		init_attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
488 		iser_conn->max_cmds =
489 			ISER_GET_MAX_XMIT_CMDS(ISER_QP_SIG_MAX_REQ_DTOS);
490 	} else {
491 		if (dev_attr->max_qp_wr > ISER_QP_MAX_REQ_DTOS) {
492 			init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS + 1;
493 			iser_conn->max_cmds =
494 				ISER_GET_MAX_XMIT_CMDS(ISER_QP_MAX_REQ_DTOS);
495 		} else {
496 			init_attr.cap.max_send_wr = dev_attr->max_qp_wr;
497 			iser_conn->max_cmds =
498 				ISER_GET_MAX_XMIT_CMDS(dev_attr->max_qp_wr);
499 			iser_dbg("device %s supports max_send_wr %d\n",
500 				 device->ib_device->name, dev_attr->max_qp_wr);
501 		}
502 	}
503 
504 	ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
505 	if (ret)
506 		goto out_err;
507 
508 	ib_conn->qp = ib_conn->cma_id->qp;
509 	iser_info("setting conn %p cma_id %p qp %p\n",
510 		  ib_conn, ib_conn->cma_id,
511 		  ib_conn->cma_id->qp);
512 	return ret;
513 
514 out_err:
515 	mutex_lock(&ig.connlist_mutex);
516 	ib_conn->comp->active_qps--;
517 	mutex_unlock(&ig.connlist_mutex);
518 	iser_err("unable to alloc mem or create resource, err %d\n", ret);
519 
520 	return ret;
521 }
522 
523 /**
524  * based on the resolved device node GUID see if there already allocated
525  * device for this device. If there's no such, create one.
526  */
527 static
528 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
529 {
530 	struct iser_device *device;
531 
532 	mutex_lock(&ig.device_list_mutex);
533 
534 	list_for_each_entry(device, &ig.device_list, ig_list)
535 		/* find if there's a match using the node GUID */
536 		if (device->ib_device->node_guid == cma_id->device->node_guid)
537 			goto inc_refcnt;
538 
539 	device = kzalloc(sizeof *device, GFP_KERNEL);
540 	if (device == NULL)
541 		goto out;
542 
543 	/* assign this device to the device */
544 	device->ib_device = cma_id->device;
545 	/* init the device and link it into ig device list */
546 	if (iser_create_device_ib_res(device)) {
547 		kfree(device);
548 		device = NULL;
549 		goto out;
550 	}
551 	list_add(&device->ig_list, &ig.device_list);
552 
553 inc_refcnt:
554 	device->refcount++;
555 out:
556 	mutex_unlock(&ig.device_list_mutex);
557 	return device;
558 }
559 
560 /* if there's no demand for this device, release it */
561 static void iser_device_try_release(struct iser_device *device)
562 {
563 	mutex_lock(&ig.device_list_mutex);
564 	device->refcount--;
565 	iser_info("device %p refcount %d\n", device, device->refcount);
566 	if (!device->refcount) {
567 		iser_free_device_ib_res(device);
568 		list_del(&device->ig_list);
569 		kfree(device);
570 	}
571 	mutex_unlock(&ig.device_list_mutex);
572 }
573 
574 /**
575  * Called with state mutex held
576  **/
577 static int iser_conn_state_comp_exch(struct iser_conn *iser_conn,
578 				     enum iser_conn_state comp,
579 				     enum iser_conn_state exch)
580 {
581 	int ret;
582 
583 	ret = (iser_conn->state == comp);
584 	if (ret)
585 		iser_conn->state = exch;
586 
587 	return ret;
588 }
589 
590 void iser_release_work(struct work_struct *work)
591 {
592 	struct iser_conn *iser_conn;
593 
594 	iser_conn = container_of(work, struct iser_conn, release_work);
595 
596 	/* Wait for conn_stop to complete */
597 	wait_for_completion(&iser_conn->stop_completion);
598 	/* Wait for IB resouces cleanup to complete */
599 	wait_for_completion(&iser_conn->ib_completion);
600 
601 	mutex_lock(&iser_conn->state_mutex);
602 	iser_conn->state = ISER_CONN_DOWN;
603 	mutex_unlock(&iser_conn->state_mutex);
604 
605 	iser_conn_release(iser_conn);
606 }
607 
608 /**
609  * iser_free_ib_conn_res - release IB related resources
610  * @iser_conn: iser connection struct
611  * @destroy: indicator if we need to try to release the
612  *     iser device and memory regoins pool (only iscsi
613  *     shutdown and DEVICE_REMOVAL will use this).
614  *
615  * This routine is called with the iser state mutex held
616  * so the cm_id removal is out of here. It is Safe to
617  * be invoked multiple times.
618  */
619 static void iser_free_ib_conn_res(struct iser_conn *iser_conn,
620 				  bool destroy)
621 {
622 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
623 	struct iser_device *device = ib_conn->device;
624 
625 	iser_info("freeing conn %p cma_id %p qp %p\n",
626 		  iser_conn, ib_conn->cma_id, ib_conn->qp);
627 
628 	if (ib_conn->qp != NULL) {
629 		ib_conn->comp->active_qps--;
630 		rdma_destroy_qp(ib_conn->cma_id);
631 		ib_conn->qp = NULL;
632 	}
633 
634 	if (destroy) {
635 		if (iser_conn->rx_descs)
636 			iser_free_rx_descriptors(iser_conn);
637 
638 		if (device != NULL) {
639 			iser_device_try_release(device);
640 			ib_conn->device = NULL;
641 		}
642 	}
643 }
644 
645 /**
646  * Frees all conn objects and deallocs conn descriptor
647  */
648 void iser_conn_release(struct iser_conn *iser_conn)
649 {
650 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
651 
652 	mutex_lock(&ig.connlist_mutex);
653 	list_del(&iser_conn->conn_list);
654 	mutex_unlock(&ig.connlist_mutex);
655 
656 	mutex_lock(&iser_conn->state_mutex);
657 	/* In case we endup here without ep_disconnect being invoked. */
658 	if (iser_conn->state != ISER_CONN_DOWN) {
659 		iser_warn("iser conn %p state %d, expected state down.\n",
660 			  iser_conn, iser_conn->state);
661 		iscsi_destroy_endpoint(iser_conn->ep);
662 		iser_conn->state = ISER_CONN_DOWN;
663 	}
664 	/*
665 	 * In case we never got to bind stage, we still need to
666 	 * release IB resources (which is safe to call more than once).
667 	 */
668 	iser_free_ib_conn_res(iser_conn, true);
669 	mutex_unlock(&iser_conn->state_mutex);
670 
671 	if (ib_conn->cma_id != NULL) {
672 		rdma_destroy_id(ib_conn->cma_id);
673 		ib_conn->cma_id = NULL;
674 	}
675 
676 	kfree(iser_conn);
677 }
678 
679 /**
680  * triggers start of the disconnect procedures and wait for them to be done
681  * Called with state mutex held
682  */
683 int iser_conn_terminate(struct iser_conn *iser_conn)
684 {
685 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
686 	struct ib_send_wr *bad_wr;
687 	int err = 0;
688 
689 	/* terminate the iser conn only if the conn state is UP */
690 	if (!iser_conn_state_comp_exch(iser_conn, ISER_CONN_UP,
691 				       ISER_CONN_TERMINATING))
692 		return 0;
693 
694 	iser_info("iser_conn %p state %d\n", iser_conn, iser_conn->state);
695 
696 	/* suspend queuing of new iscsi commands */
697 	if (iser_conn->iscsi_conn)
698 		iscsi_suspend_queue(iser_conn->iscsi_conn);
699 
700 	/*
701 	 * In case we didn't already clean up the cma_id (peer initiated
702 	 * a disconnection), we need to Cause the CMA to change the QP
703 	 * state to ERROR.
704 	 */
705 	if (ib_conn->cma_id) {
706 		err = rdma_disconnect(ib_conn->cma_id);
707 		if (err)
708 			iser_err("Failed to disconnect, conn: 0x%p err %d\n",
709 				 iser_conn, err);
710 
711 		/* post an indication that all flush errors were consumed */
712 		err = ib_post_send(ib_conn->qp, &ib_conn->beacon, &bad_wr);
713 		if (err) {
714 			iser_err("conn %p failed to post beacon", ib_conn);
715 			return 1;
716 		}
717 
718 		wait_for_completion(&ib_conn->flush_comp);
719 	}
720 
721 	return 1;
722 }
723 
724 /**
725  * Called with state mutex held
726  **/
727 static void iser_connect_error(struct rdma_cm_id *cma_id)
728 {
729 	struct iser_conn *iser_conn;
730 
731 	iser_conn = (struct iser_conn *)cma_id->context;
732 	iser_conn->state = ISER_CONN_TERMINATING;
733 }
734 
735 /**
736  * Called with state mutex held
737  **/
738 static void iser_addr_handler(struct rdma_cm_id *cma_id)
739 {
740 	struct iser_device *device;
741 	struct iser_conn   *iser_conn;
742 	struct ib_conn   *ib_conn;
743 	int    ret;
744 
745 	iser_conn = (struct iser_conn *)cma_id->context;
746 	if (iser_conn->state != ISER_CONN_PENDING)
747 		/* bailout */
748 		return;
749 
750 	ib_conn = &iser_conn->ib_conn;
751 	device = iser_device_find_by_ib_device(cma_id);
752 	if (!device) {
753 		iser_err("device lookup/creation failed\n");
754 		iser_connect_error(cma_id);
755 		return;
756 	}
757 
758 	ib_conn->device = device;
759 
760 	/* connection T10-PI support */
761 	if (iser_pi_enable) {
762 		if (!(device->dev_attr.device_cap_flags &
763 		      IB_DEVICE_SIGNATURE_HANDOVER)) {
764 			iser_warn("T10-PI requested but not supported on %s, "
765 				  "continue without T10-PI\n",
766 				  ib_conn->device->ib_device->name);
767 			ib_conn->pi_support = false;
768 		} else {
769 			ib_conn->pi_support = true;
770 		}
771 	}
772 
773 	ret = rdma_resolve_route(cma_id, 1000);
774 	if (ret) {
775 		iser_err("resolve route failed: %d\n", ret);
776 		iser_connect_error(cma_id);
777 		return;
778 	}
779 }
780 
781 /**
782  * Called with state mutex held
783  **/
784 static void iser_route_handler(struct rdma_cm_id *cma_id)
785 {
786 	struct rdma_conn_param conn_param;
787 	int    ret;
788 	struct iser_cm_hdr req_hdr;
789 	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
790 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
791 	struct iser_device *device = ib_conn->device;
792 
793 	if (iser_conn->state != ISER_CONN_PENDING)
794 		/* bailout */
795 		return;
796 
797 	ret = iser_create_ib_conn_res(ib_conn);
798 	if (ret)
799 		goto failure;
800 
801 	memset(&conn_param, 0, sizeof conn_param);
802 	conn_param.responder_resources = device->dev_attr.max_qp_rd_atom;
803 	conn_param.initiator_depth     = 1;
804 	conn_param.retry_count	       = 7;
805 	conn_param.rnr_retry_count     = 6;
806 
807 	memset(&req_hdr, 0, sizeof(req_hdr));
808 	req_hdr.flags = (ISER_ZBVA_NOT_SUPPORTED |
809 			ISER_SEND_W_INV_NOT_SUPPORTED);
810 	conn_param.private_data		= (void *)&req_hdr;
811 	conn_param.private_data_len	= sizeof(struct iser_cm_hdr);
812 
813 	ret = rdma_connect(cma_id, &conn_param);
814 	if (ret) {
815 		iser_err("failure connecting: %d\n", ret);
816 		goto failure;
817 	}
818 
819 	return;
820 failure:
821 	iser_connect_error(cma_id);
822 }
823 
824 static void iser_connected_handler(struct rdma_cm_id *cma_id)
825 {
826 	struct iser_conn *iser_conn;
827 	struct ib_qp_attr attr;
828 	struct ib_qp_init_attr init_attr;
829 
830 	iser_conn = (struct iser_conn *)cma_id->context;
831 	if (iser_conn->state != ISER_CONN_PENDING)
832 		/* bailout */
833 		return;
834 
835 	(void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
836 	iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
837 
838 	iser_conn->state = ISER_CONN_UP;
839 	complete(&iser_conn->up_completion);
840 }
841 
842 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
843 {
844 	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
845 
846 	if (iser_conn_terminate(iser_conn)) {
847 		if (iser_conn->iscsi_conn)
848 			iscsi_conn_failure(iser_conn->iscsi_conn,
849 					   ISCSI_ERR_CONN_FAILED);
850 		else
851 			iser_err("iscsi_iser connection isn't bound\n");
852 	}
853 }
854 
855 static void iser_cleanup_handler(struct rdma_cm_id *cma_id,
856 				 bool destroy)
857 {
858 	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
859 
860 	/*
861 	 * We are not guaranteed that we visited disconnected_handler
862 	 * by now, call it here to be safe that we handle CM drep
863 	 * and flush errors.
864 	 */
865 	iser_disconnected_handler(cma_id);
866 	iser_free_ib_conn_res(iser_conn, destroy);
867 	complete(&iser_conn->ib_completion);
868 };
869 
870 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
871 {
872 	struct iser_conn *iser_conn;
873 	int ret = 0;
874 
875 	iser_conn = (struct iser_conn *)cma_id->context;
876 	iser_info("event %d status %d conn %p id %p\n",
877 		  event->event, event->status, cma_id->context, cma_id);
878 
879 	mutex_lock(&iser_conn->state_mutex);
880 	switch (event->event) {
881 	case RDMA_CM_EVENT_ADDR_RESOLVED:
882 		iser_addr_handler(cma_id);
883 		break;
884 	case RDMA_CM_EVENT_ROUTE_RESOLVED:
885 		iser_route_handler(cma_id);
886 		break;
887 	case RDMA_CM_EVENT_ESTABLISHED:
888 		iser_connected_handler(cma_id);
889 		break;
890 	case RDMA_CM_EVENT_ADDR_ERROR:
891 	case RDMA_CM_EVENT_ROUTE_ERROR:
892 	case RDMA_CM_EVENT_CONNECT_ERROR:
893 	case RDMA_CM_EVENT_UNREACHABLE:
894 	case RDMA_CM_EVENT_REJECTED:
895 		iser_connect_error(cma_id);
896 		break;
897 	case RDMA_CM_EVENT_DISCONNECTED:
898 	case RDMA_CM_EVENT_ADDR_CHANGE:
899 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
900 		iser_cleanup_handler(cma_id, false);
901 		break;
902 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
903 		/*
904 		 * we *must* destroy the device as we cannot rely
905 		 * on iscsid to be around to initiate error handling.
906 		 * also if we are not in state DOWN implicitly destroy
907 		 * the cma_id.
908 		 */
909 		iser_cleanup_handler(cma_id, true);
910 		if (iser_conn->state != ISER_CONN_DOWN) {
911 			iser_conn->ib_conn.cma_id = NULL;
912 			ret = 1;
913 		}
914 		break;
915 	default:
916 		iser_err("Unexpected RDMA CM event (%d)\n", event->event);
917 		break;
918 	}
919 	mutex_unlock(&iser_conn->state_mutex);
920 
921 	return ret;
922 }
923 
924 void iser_conn_init(struct iser_conn *iser_conn)
925 {
926 	iser_conn->state = ISER_CONN_INIT;
927 	iser_conn->ib_conn.post_recv_buf_count = 0;
928 	init_completion(&iser_conn->ib_conn.flush_comp);
929 	init_completion(&iser_conn->stop_completion);
930 	init_completion(&iser_conn->ib_completion);
931 	init_completion(&iser_conn->up_completion);
932 	INIT_LIST_HEAD(&iser_conn->conn_list);
933 	spin_lock_init(&iser_conn->ib_conn.lock);
934 	mutex_init(&iser_conn->state_mutex);
935 }
936 
937  /**
938  * starts the process of connecting to the target
939  * sleeps until the connection is established or rejected
940  */
941 int iser_connect(struct iser_conn   *iser_conn,
942 		 struct sockaddr    *src_addr,
943 		 struct sockaddr    *dst_addr,
944 		 int                 non_blocking)
945 {
946 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
947 	int err = 0;
948 
949 	mutex_lock(&iser_conn->state_mutex);
950 
951 	sprintf(iser_conn->name, "%pISp", dst_addr);
952 
953 	iser_info("connecting to: %s\n", iser_conn->name);
954 
955 	/* the device is known only --after-- address resolution */
956 	ib_conn->device = NULL;
957 
958 	iser_conn->state = ISER_CONN_PENDING;
959 
960 	ib_conn->beacon.wr_id = ISER_BEACON_WRID;
961 	ib_conn->beacon.opcode = IB_WR_SEND;
962 
963 	ib_conn->cma_id = rdma_create_id(iser_cma_handler,
964 					 (void *)iser_conn,
965 					 RDMA_PS_TCP, IB_QPT_RC);
966 	if (IS_ERR(ib_conn->cma_id)) {
967 		err = PTR_ERR(ib_conn->cma_id);
968 		iser_err("rdma_create_id failed: %d\n", err);
969 		goto id_failure;
970 	}
971 
972 	err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
973 	if (err) {
974 		iser_err("rdma_resolve_addr failed: %d\n", err);
975 		goto addr_failure;
976 	}
977 
978 	if (!non_blocking) {
979 		wait_for_completion_interruptible(&iser_conn->up_completion);
980 
981 		if (iser_conn->state != ISER_CONN_UP) {
982 			err =  -EIO;
983 			goto connect_failure;
984 		}
985 	}
986 	mutex_unlock(&iser_conn->state_mutex);
987 
988 	mutex_lock(&ig.connlist_mutex);
989 	list_add(&iser_conn->conn_list, &ig.connlist);
990 	mutex_unlock(&ig.connlist_mutex);
991 	return 0;
992 
993 id_failure:
994 	ib_conn->cma_id = NULL;
995 addr_failure:
996 	iser_conn->state = ISER_CONN_DOWN;
997 connect_failure:
998 	mutex_unlock(&iser_conn->state_mutex);
999 	iser_conn_release(iser_conn);
1000 	return err;
1001 }
1002 
1003 int iser_post_recvl(struct iser_conn *iser_conn)
1004 {
1005 	struct ib_recv_wr rx_wr, *rx_wr_failed;
1006 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
1007 	struct ib_sge	  sge;
1008 	int ib_ret;
1009 
1010 	sge.addr   = iser_conn->login_resp_dma;
1011 	sge.length = ISER_RX_LOGIN_SIZE;
1012 	sge.lkey   = ib_conn->device->mr->lkey;
1013 
1014 	rx_wr.wr_id   = (uintptr_t)iser_conn->login_resp_buf;
1015 	rx_wr.sg_list = &sge;
1016 	rx_wr.num_sge = 1;
1017 	rx_wr.next    = NULL;
1018 
1019 	ib_conn->post_recv_buf_count++;
1020 	ib_ret	= ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
1021 	if (ib_ret) {
1022 		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1023 		ib_conn->post_recv_buf_count--;
1024 	}
1025 	return ib_ret;
1026 }
1027 
1028 int iser_post_recvm(struct iser_conn *iser_conn, int count)
1029 {
1030 	struct ib_recv_wr *rx_wr, *rx_wr_failed;
1031 	int i, ib_ret;
1032 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
1033 	unsigned int my_rx_head = iser_conn->rx_desc_head;
1034 	struct iser_rx_desc *rx_desc;
1035 
1036 	for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
1037 		rx_desc		= &iser_conn->rx_descs[my_rx_head];
1038 		rx_wr->wr_id	= (uintptr_t)rx_desc;
1039 		rx_wr->sg_list	= &rx_desc->rx_sg;
1040 		rx_wr->num_sge	= 1;
1041 		rx_wr->next	= rx_wr + 1;
1042 		my_rx_head = (my_rx_head + 1) & iser_conn->qp_max_recv_dtos_mask;
1043 	}
1044 
1045 	rx_wr--;
1046 	rx_wr->next = NULL; /* mark end of work requests list */
1047 
1048 	ib_conn->post_recv_buf_count += count;
1049 	ib_ret	= ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
1050 	if (ib_ret) {
1051 		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1052 		ib_conn->post_recv_buf_count -= count;
1053 	} else
1054 		iser_conn->rx_desc_head = my_rx_head;
1055 	return ib_ret;
1056 }
1057 
1058 
1059 /**
1060  * iser_start_send - Initiate a Send DTO operation
1061  *
1062  * returns 0 on success, -1 on failure
1063  */
1064 int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
1065 		   bool signal)
1066 {
1067 	int		  ib_ret;
1068 	struct ib_send_wr send_wr, *send_wr_failed;
1069 
1070 	ib_dma_sync_single_for_device(ib_conn->device->ib_device,
1071 				      tx_desc->dma_addr, ISER_HEADERS_LEN,
1072 				      DMA_TO_DEVICE);
1073 
1074 	send_wr.next	   = NULL;
1075 	send_wr.wr_id	   = (uintptr_t)tx_desc;
1076 	send_wr.sg_list	   = tx_desc->tx_sg;
1077 	send_wr.num_sge	   = tx_desc->num_sge;
1078 	send_wr.opcode	   = IB_WR_SEND;
1079 	send_wr.send_flags = signal ? IB_SEND_SIGNALED : 0;
1080 
1081 	ib_ret = ib_post_send(ib_conn->qp, &send_wr, &send_wr_failed);
1082 	if (ib_ret)
1083 		iser_err("ib_post_send failed, ret:%d\n", ib_ret);
1084 
1085 	return ib_ret;
1086 }
1087 
1088 /**
1089  * is_iser_tx_desc - Indicate if the completion wr_id
1090  *     is a TX descriptor or not.
1091  * @iser_conn: iser connection
1092  * @wr_id: completion WR identifier
1093  *
1094  * Since we cannot rely on wc opcode in FLUSH errors
1095  * we must work around it by checking if the wr_id address
1096  * falls in the iser connection rx_descs buffer. If so
1097  * it is an RX descriptor, otherwize it is a TX.
1098  */
1099 static inline bool
1100 is_iser_tx_desc(struct iser_conn *iser_conn, void *wr_id)
1101 {
1102 	void *start = iser_conn->rx_descs;
1103 	int len = iser_conn->num_rx_descs * sizeof(*iser_conn->rx_descs);
1104 
1105 	if (wr_id >= start && wr_id < start + len)
1106 		return false;
1107 
1108 	return true;
1109 }
1110 
1111 /**
1112  * iser_handle_comp_error() - Handle error completion
1113  * @ib_conn:   connection RDMA resources
1114  * @wc:        work completion
1115  *
1116  * Notes: We may handle a FLUSH error completion and in this case
1117  *        we only cleanup in case TX type was DATAOUT. For non-FLUSH
1118  *        error completion we should also notify iscsi layer that
1119  *        connection is failed (in case we passed bind stage).
1120  */
1121 static void
1122 iser_handle_comp_error(struct ib_conn *ib_conn,
1123 		       struct ib_wc *wc)
1124 {
1125 	void *wr_id = (void *)(uintptr_t)wc->wr_id;
1126 	struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
1127 						   ib_conn);
1128 
1129 	if (wc->status != IB_WC_WR_FLUSH_ERR)
1130 		if (iser_conn->iscsi_conn)
1131 			iscsi_conn_failure(iser_conn->iscsi_conn,
1132 					   ISCSI_ERR_CONN_FAILED);
1133 
1134 	if (wc->wr_id == ISER_FASTREG_LI_WRID)
1135 		return;
1136 
1137 	if (is_iser_tx_desc(iser_conn, wr_id)) {
1138 		struct iser_tx_desc *desc = wr_id;
1139 
1140 		if (desc->type == ISCSI_TX_DATAOUT)
1141 			kmem_cache_free(ig.desc_cache, desc);
1142 	} else {
1143 		ib_conn->post_recv_buf_count--;
1144 	}
1145 }
1146 
1147 /**
1148  * iser_handle_wc - handle a single work completion
1149  * @wc: work completion
1150  *
1151  * Soft-IRQ context, work completion can be either
1152  * SEND or RECV, and can turn out successful or
1153  * with error (or flush error).
1154  */
1155 static void iser_handle_wc(struct ib_wc *wc)
1156 {
1157 	struct ib_conn *ib_conn;
1158 	struct iser_tx_desc *tx_desc;
1159 	struct iser_rx_desc *rx_desc;
1160 
1161 	ib_conn = wc->qp->qp_context;
1162 	if (likely(wc->status == IB_WC_SUCCESS)) {
1163 		if (wc->opcode == IB_WC_RECV) {
1164 			rx_desc = (struct iser_rx_desc *)(uintptr_t)wc->wr_id;
1165 			iser_rcv_completion(rx_desc, wc->byte_len,
1166 					    ib_conn);
1167 		} else
1168 		if (wc->opcode == IB_WC_SEND) {
1169 			tx_desc = (struct iser_tx_desc *)(uintptr_t)wc->wr_id;
1170 			iser_snd_completion(tx_desc, ib_conn);
1171 		} else {
1172 			iser_err("Unknown wc opcode %d\n", wc->opcode);
1173 		}
1174 	} else {
1175 		if (wc->status != IB_WC_WR_FLUSH_ERR)
1176 			iser_err("wr id %llx status %d vend_err %x\n",
1177 				 wc->wr_id, wc->status, wc->vendor_err);
1178 		else
1179 			iser_dbg("flush error: wr id %llx\n", wc->wr_id);
1180 
1181 		if (wc->wr_id == ISER_BEACON_WRID)
1182 			/* all flush errors were consumed */
1183 			complete(&ib_conn->flush_comp);
1184 		else
1185 			iser_handle_comp_error(ib_conn, wc);
1186 	}
1187 }
1188 
1189 /**
1190  * iser_cq_tasklet_fn - iSER completion polling loop
1191  * @data: iSER completion context
1192  *
1193  * Soft-IRQ context, polling connection CQ until
1194  * either CQ was empty or we exausted polling budget
1195  */
1196 static void iser_cq_tasklet_fn(unsigned long data)
1197 {
1198 	struct iser_comp *comp = (struct iser_comp *)data;
1199 	struct ib_cq *cq = comp->cq;
1200 	struct ib_wc *const wcs = comp->wcs;
1201 	int i, n, completed = 0;
1202 
1203 	while ((n = ib_poll_cq(cq, ARRAY_SIZE(comp->wcs), wcs)) > 0) {
1204 		for (i = 0; i < n; i++)
1205 			iser_handle_wc(&wcs[i]);
1206 
1207 		completed += n;
1208 		if (completed >= iser_cq_poll_limit)
1209 			break;
1210 	}
1211 
1212 	/*
1213 	 * It is assumed here that arming CQ only once its empty
1214 	 * would not cause interrupts to be missed.
1215 	 */
1216 	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1217 
1218 	iser_dbg("got %d completions\n", completed);
1219 }
1220 
1221 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
1222 {
1223 	struct iser_comp *comp = cq_context;
1224 
1225 	tasklet_schedule(&comp->tasklet);
1226 }
1227 
1228 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
1229 			     enum iser_data_dir cmd_dir, sector_t *sector)
1230 {
1231 	struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
1232 	struct fast_reg_descriptor *desc = reg->mem_h;
1233 	unsigned long sector_size = iser_task->sc->device->sector_size;
1234 	struct ib_mr_status mr_status;
1235 	int ret;
1236 
1237 	if (desc && desc->reg_indicators & ISER_FASTREG_PROTECTED) {
1238 		desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
1239 		ret = ib_check_mr_status(desc->pi_ctx->sig_mr,
1240 					 IB_MR_CHECK_SIG_STATUS, &mr_status);
1241 		if (ret) {
1242 			pr_err("ib_check_mr_status failed, ret %d\n", ret);
1243 			goto err;
1244 		}
1245 
1246 		if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1247 			sector_t sector_off = mr_status.sig_err.sig_err_offset;
1248 
1249 			do_div(sector_off, sector_size + 8);
1250 			*sector = scsi_get_lba(iser_task->sc) + sector_off;
1251 
1252 			pr_err("PI error found type %d at sector %llx "
1253 			       "expected %x vs actual %x\n",
1254 			       mr_status.sig_err.err_type,
1255 			       (unsigned long long)*sector,
1256 			       mr_status.sig_err.expected,
1257 			       mr_status.sig_err.actual);
1258 
1259 			switch (mr_status.sig_err.err_type) {
1260 			case IB_SIG_BAD_GUARD:
1261 				return 0x1;
1262 			case IB_SIG_BAD_REFTAG:
1263 				return 0x3;
1264 			case IB_SIG_BAD_APPTAG:
1265 				return 0x2;
1266 			}
1267 		}
1268 	}
1269 
1270 	return 0;
1271 err:
1272 	/* Not alot we can do here, return ambiguous guard error */
1273 	return 0x1;
1274 }
1275