xref: /linux/drivers/infiniband/ulp/srp/ib_srp.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /*
2  * Copyright (c) 2005 Cisco Systems.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34 
35 #include <linux/module.h>
36 #include <linux/init.h>
37 #include <linux/slab.h>
38 #include <linux/err.h>
39 #include <linux/string.h>
40 #include <linux/parser.h>
41 #include <linux/random.h>
42 #include <linux/jiffies.h>
43 #include <rdma/ib_cache.h>
44 
45 #include <linux/atomic.h>
46 
47 #include <scsi/scsi.h>
48 #include <scsi/scsi_device.h>
49 #include <scsi/scsi_dbg.h>
50 #include <scsi/scsi_tcq.h>
51 #include <scsi/srp.h>
52 #include <scsi/scsi_transport_srp.h>
53 
54 #include "ib_srp.h"
55 
56 #define DRV_NAME	"ib_srp"
57 #define PFX		DRV_NAME ": "
58 #define DRV_VERSION	"2.0"
59 #define DRV_RELDATE	"July 26, 2015"
60 
61 MODULE_AUTHOR("Roland Dreier");
62 MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol initiator");
63 MODULE_LICENSE("Dual BSD/GPL");
64 MODULE_VERSION(DRV_VERSION);
65 MODULE_INFO(release_date, DRV_RELDATE);
66 
67 static unsigned int srp_sg_tablesize;
68 static unsigned int cmd_sg_entries;
69 static unsigned int indirect_sg_entries;
70 static bool allow_ext_sg;
71 static bool prefer_fr = true;
72 static bool register_always = true;
73 static int topspin_workarounds = 1;
74 
75 module_param(srp_sg_tablesize, uint, 0444);
76 MODULE_PARM_DESC(srp_sg_tablesize, "Deprecated name for cmd_sg_entries");
77 
78 module_param(cmd_sg_entries, uint, 0444);
79 MODULE_PARM_DESC(cmd_sg_entries,
80 		 "Default number of gather/scatter entries in the SRP command (default is 12, max 255)");
81 
82 module_param(indirect_sg_entries, uint, 0444);
83 MODULE_PARM_DESC(indirect_sg_entries,
84 		 "Default max number of gather/scatter entries (default is 12, max is " __stringify(SCSI_MAX_SG_CHAIN_SEGMENTS) ")");
85 
86 module_param(allow_ext_sg, bool, 0444);
87 MODULE_PARM_DESC(allow_ext_sg,
88 		  "Default behavior when there are more than cmd_sg_entries S/G entries after mapping; fails the request when false (default false)");
89 
90 module_param(topspin_workarounds, int, 0444);
91 MODULE_PARM_DESC(topspin_workarounds,
92 		 "Enable workarounds for Topspin/Cisco SRP target bugs if != 0");
93 
94 module_param(prefer_fr, bool, 0444);
95 MODULE_PARM_DESC(prefer_fr,
96 "Whether to use fast registration if both FMR and fast registration are supported");
97 
98 module_param(register_always, bool, 0444);
99 MODULE_PARM_DESC(register_always,
100 		 "Use memory registration even for contiguous memory regions");
101 
102 static const struct kernel_param_ops srp_tmo_ops;
103 
104 static int srp_reconnect_delay = 10;
105 module_param_cb(reconnect_delay, &srp_tmo_ops, &srp_reconnect_delay,
106 		S_IRUGO | S_IWUSR);
107 MODULE_PARM_DESC(reconnect_delay, "Time between successive reconnect attempts");
108 
109 static int srp_fast_io_fail_tmo = 15;
110 module_param_cb(fast_io_fail_tmo, &srp_tmo_ops, &srp_fast_io_fail_tmo,
111 		S_IRUGO | S_IWUSR);
112 MODULE_PARM_DESC(fast_io_fail_tmo,
113 		 "Number of seconds between the observation of a transport"
114 		 " layer error and failing all I/O. \"off\" means that this"
115 		 " functionality is disabled.");
116 
117 static int srp_dev_loss_tmo = 600;
118 module_param_cb(dev_loss_tmo, &srp_tmo_ops, &srp_dev_loss_tmo,
119 		S_IRUGO | S_IWUSR);
120 MODULE_PARM_DESC(dev_loss_tmo,
121 		 "Maximum number of seconds that the SRP transport should"
122 		 " insulate transport layer errors. After this time has been"
123 		 " exceeded the SCSI host is removed. Should be"
124 		 " between 1 and " __stringify(SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
125 		 " if fast_io_fail_tmo has not been set. \"off\" means that"
126 		 " this functionality is disabled.");
127 
128 static unsigned ch_count;
129 module_param(ch_count, uint, 0444);
130 MODULE_PARM_DESC(ch_count,
131 		 "Number of RDMA channels to use for communication with an SRP target. Using more than one channel improves performance if the HCA supports multiple completion vectors. The default value is the minimum of four times the number of online CPU sockets and the number of completion vectors supported by the HCA.");
132 
133 static void srp_add_one(struct ib_device *device);
134 static void srp_remove_one(struct ib_device *device, void *client_data);
135 static void srp_recv_completion(struct ib_cq *cq, void *ch_ptr);
136 static void srp_send_completion(struct ib_cq *cq, void *ch_ptr);
137 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);
138 
139 static struct scsi_transport_template *ib_srp_transport_template;
140 static struct workqueue_struct *srp_remove_wq;
141 
142 static struct ib_client srp_client = {
143 	.name   = "srp",
144 	.add    = srp_add_one,
145 	.remove = srp_remove_one
146 };
147 
148 static struct ib_sa_client srp_sa_client;
149 
150 static int srp_tmo_get(char *buffer, const struct kernel_param *kp)
151 {
152 	int tmo = *(int *)kp->arg;
153 
154 	if (tmo >= 0)
155 		return sprintf(buffer, "%d", tmo);
156 	else
157 		return sprintf(buffer, "off");
158 }
159 
160 static int srp_tmo_set(const char *val, const struct kernel_param *kp)
161 {
162 	int tmo, res;
163 
164 	res = srp_parse_tmo(&tmo, val);
165 	if (res)
166 		goto out;
167 
168 	if (kp->arg == &srp_reconnect_delay)
169 		res = srp_tmo_valid(tmo, srp_fast_io_fail_tmo,
170 				    srp_dev_loss_tmo);
171 	else if (kp->arg == &srp_fast_io_fail_tmo)
172 		res = srp_tmo_valid(srp_reconnect_delay, tmo, srp_dev_loss_tmo);
173 	else
174 		res = srp_tmo_valid(srp_reconnect_delay, srp_fast_io_fail_tmo,
175 				    tmo);
176 	if (res)
177 		goto out;
178 	*(int *)kp->arg = tmo;
179 
180 out:
181 	return res;
182 }
183 
184 static const struct kernel_param_ops srp_tmo_ops = {
185 	.get = srp_tmo_get,
186 	.set = srp_tmo_set,
187 };
188 
189 static inline struct srp_target_port *host_to_target(struct Scsi_Host *host)
190 {
191 	return (struct srp_target_port *) host->hostdata;
192 }
193 
194 static const char *srp_target_info(struct Scsi_Host *host)
195 {
196 	return host_to_target(host)->target_name;
197 }
198 
199 static int srp_target_is_topspin(struct srp_target_port *target)
200 {
201 	static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
202 	static const u8 cisco_oui[3]   = { 0x00, 0x1b, 0x0d };
203 
204 	return topspin_workarounds &&
205 		(!memcmp(&target->ioc_guid, topspin_oui, sizeof topspin_oui) ||
206 		 !memcmp(&target->ioc_guid, cisco_oui, sizeof cisco_oui));
207 }
208 
209 static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
210 				   gfp_t gfp_mask,
211 				   enum dma_data_direction direction)
212 {
213 	struct srp_iu *iu;
214 
215 	iu = kmalloc(sizeof *iu, gfp_mask);
216 	if (!iu)
217 		goto out;
218 
219 	iu->buf = kzalloc(size, gfp_mask);
220 	if (!iu->buf)
221 		goto out_free_iu;
222 
223 	iu->dma = ib_dma_map_single(host->srp_dev->dev, iu->buf, size,
224 				    direction);
225 	if (ib_dma_mapping_error(host->srp_dev->dev, iu->dma))
226 		goto out_free_buf;
227 
228 	iu->size      = size;
229 	iu->direction = direction;
230 
231 	return iu;
232 
233 out_free_buf:
234 	kfree(iu->buf);
235 out_free_iu:
236 	kfree(iu);
237 out:
238 	return NULL;
239 }
240 
241 static void srp_free_iu(struct srp_host *host, struct srp_iu *iu)
242 {
243 	if (!iu)
244 		return;
245 
246 	ib_dma_unmap_single(host->srp_dev->dev, iu->dma, iu->size,
247 			    iu->direction);
248 	kfree(iu->buf);
249 	kfree(iu);
250 }
251 
252 static void srp_qp_event(struct ib_event *event, void *context)
253 {
254 	pr_debug("QP event %s (%d)\n",
255 		 ib_event_msg(event->event), event->event);
256 }
257 
258 static int srp_init_qp(struct srp_target_port *target,
259 		       struct ib_qp *qp)
260 {
261 	struct ib_qp_attr *attr;
262 	int ret;
263 
264 	attr = kmalloc(sizeof *attr, GFP_KERNEL);
265 	if (!attr)
266 		return -ENOMEM;
267 
268 	ret = ib_find_cached_pkey(target->srp_host->srp_dev->dev,
269 				  target->srp_host->port,
270 				  be16_to_cpu(target->pkey),
271 				  &attr->pkey_index);
272 	if (ret)
273 		goto out;
274 
275 	attr->qp_state        = IB_QPS_INIT;
276 	attr->qp_access_flags = (IB_ACCESS_REMOTE_READ |
277 				    IB_ACCESS_REMOTE_WRITE);
278 	attr->port_num        = target->srp_host->port;
279 
280 	ret = ib_modify_qp(qp, attr,
281 			   IB_QP_STATE		|
282 			   IB_QP_PKEY_INDEX	|
283 			   IB_QP_ACCESS_FLAGS	|
284 			   IB_QP_PORT);
285 
286 out:
287 	kfree(attr);
288 	return ret;
289 }
290 
291 static int srp_new_cm_id(struct srp_rdma_ch *ch)
292 {
293 	struct srp_target_port *target = ch->target;
294 	struct ib_cm_id *new_cm_id;
295 
296 	new_cm_id = ib_create_cm_id(target->srp_host->srp_dev->dev,
297 				    srp_cm_handler, ch);
298 	if (IS_ERR(new_cm_id))
299 		return PTR_ERR(new_cm_id);
300 
301 	if (ch->cm_id)
302 		ib_destroy_cm_id(ch->cm_id);
303 	ch->cm_id = new_cm_id;
304 	ch->path.sgid = target->sgid;
305 	ch->path.dgid = target->orig_dgid;
306 	ch->path.pkey = target->pkey;
307 	ch->path.service_id = target->service_id;
308 
309 	return 0;
310 }
311 
312 static struct ib_fmr_pool *srp_alloc_fmr_pool(struct srp_target_port *target)
313 {
314 	struct srp_device *dev = target->srp_host->srp_dev;
315 	struct ib_fmr_pool_param fmr_param;
316 
317 	memset(&fmr_param, 0, sizeof(fmr_param));
318 	fmr_param.pool_size	    = target->scsi_host->can_queue;
319 	fmr_param.dirty_watermark   = fmr_param.pool_size / 4;
320 	fmr_param.cache		    = 1;
321 	fmr_param.max_pages_per_fmr = dev->max_pages_per_mr;
322 	fmr_param.page_shift	    = ilog2(dev->mr_page_size);
323 	fmr_param.access	    = (IB_ACCESS_LOCAL_WRITE |
324 				       IB_ACCESS_REMOTE_WRITE |
325 				       IB_ACCESS_REMOTE_READ);
326 
327 	return ib_create_fmr_pool(dev->pd, &fmr_param);
328 }
329 
330 /**
331  * srp_destroy_fr_pool() - free the resources owned by a pool
332  * @pool: Fast registration pool to be destroyed.
333  */
334 static void srp_destroy_fr_pool(struct srp_fr_pool *pool)
335 {
336 	int i;
337 	struct srp_fr_desc *d;
338 
339 	if (!pool)
340 		return;
341 
342 	for (i = 0, d = &pool->desc[0]; i < pool->size; i++, d++) {
343 		if (d->frpl)
344 			ib_free_fast_reg_page_list(d->frpl);
345 		if (d->mr)
346 			ib_dereg_mr(d->mr);
347 	}
348 	kfree(pool);
349 }
350 
351 /**
352  * srp_create_fr_pool() - allocate and initialize a pool for fast registration
353  * @device:            IB device to allocate fast registration descriptors for.
354  * @pd:                Protection domain associated with the FR descriptors.
355  * @pool_size:         Number of descriptors to allocate.
356  * @max_page_list_len: Maximum fast registration work request page list length.
357  */
358 static struct srp_fr_pool *srp_create_fr_pool(struct ib_device *device,
359 					      struct ib_pd *pd, int pool_size,
360 					      int max_page_list_len)
361 {
362 	struct srp_fr_pool *pool;
363 	struct srp_fr_desc *d;
364 	struct ib_mr *mr;
365 	struct ib_fast_reg_page_list *frpl;
366 	int i, ret = -EINVAL;
367 
368 	if (pool_size <= 0)
369 		goto err;
370 	ret = -ENOMEM;
371 	pool = kzalloc(sizeof(struct srp_fr_pool) +
372 		       pool_size * sizeof(struct srp_fr_desc), GFP_KERNEL);
373 	if (!pool)
374 		goto err;
375 	pool->size = pool_size;
376 	pool->max_page_list_len = max_page_list_len;
377 	spin_lock_init(&pool->lock);
378 	INIT_LIST_HEAD(&pool->free_list);
379 
380 	for (i = 0, d = &pool->desc[0]; i < pool->size; i++, d++) {
381 		mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG,
382 				 max_page_list_len);
383 		if (IS_ERR(mr)) {
384 			ret = PTR_ERR(mr);
385 			goto destroy_pool;
386 		}
387 		d->mr = mr;
388 		frpl = ib_alloc_fast_reg_page_list(device, max_page_list_len);
389 		if (IS_ERR(frpl)) {
390 			ret = PTR_ERR(frpl);
391 			goto destroy_pool;
392 		}
393 		d->frpl = frpl;
394 		list_add_tail(&d->entry, &pool->free_list);
395 	}
396 
397 out:
398 	return pool;
399 
400 destroy_pool:
401 	srp_destroy_fr_pool(pool);
402 
403 err:
404 	pool = ERR_PTR(ret);
405 	goto out;
406 }
407 
408 /**
409  * srp_fr_pool_get() - obtain a descriptor suitable for fast registration
410  * @pool: Pool to obtain descriptor from.
411  */
412 static struct srp_fr_desc *srp_fr_pool_get(struct srp_fr_pool *pool)
413 {
414 	struct srp_fr_desc *d = NULL;
415 	unsigned long flags;
416 
417 	spin_lock_irqsave(&pool->lock, flags);
418 	if (!list_empty(&pool->free_list)) {
419 		d = list_first_entry(&pool->free_list, typeof(*d), entry);
420 		list_del(&d->entry);
421 	}
422 	spin_unlock_irqrestore(&pool->lock, flags);
423 
424 	return d;
425 }
426 
427 /**
428  * srp_fr_pool_put() - put an FR descriptor back in the free list
429  * @pool: Pool the descriptor was allocated from.
430  * @desc: Pointer to an array of fast registration descriptor pointers.
431  * @n:    Number of descriptors to put back.
432  *
433  * Note: The caller must already have queued an invalidation request for
434  * desc->mr->rkey before calling this function.
435  */
436 static void srp_fr_pool_put(struct srp_fr_pool *pool, struct srp_fr_desc **desc,
437 			    int n)
438 {
439 	unsigned long flags;
440 	int i;
441 
442 	spin_lock_irqsave(&pool->lock, flags);
443 	for (i = 0; i < n; i++)
444 		list_add(&desc[i]->entry, &pool->free_list);
445 	spin_unlock_irqrestore(&pool->lock, flags);
446 }
447 
448 static struct srp_fr_pool *srp_alloc_fr_pool(struct srp_target_port *target)
449 {
450 	struct srp_device *dev = target->srp_host->srp_dev;
451 
452 	return srp_create_fr_pool(dev->dev, dev->pd,
453 				  target->scsi_host->can_queue,
454 				  dev->max_pages_per_mr);
455 }
456 
457 /**
458  * srp_destroy_qp() - destroy an RDMA queue pair
459  * @ch: SRP RDMA channel.
460  *
461  * Change a queue pair into the error state and wait until all receive
462  * completions have been processed before destroying it. This avoids that
463  * the receive completion handler can access the queue pair while it is
464  * being destroyed.
465  */
466 static void srp_destroy_qp(struct srp_rdma_ch *ch)
467 {
468 	static struct ib_qp_attr attr = { .qp_state = IB_QPS_ERR };
469 	static struct ib_recv_wr wr = { .wr_id = SRP_LAST_WR_ID };
470 	struct ib_recv_wr *bad_wr;
471 	int ret;
472 
473 	/* Destroying a QP and reusing ch->done is only safe if not connected */
474 	WARN_ON_ONCE(ch->connected);
475 
476 	ret = ib_modify_qp(ch->qp, &attr, IB_QP_STATE);
477 	WARN_ONCE(ret, "ib_cm_init_qp_attr() returned %d\n", ret);
478 	if (ret)
479 		goto out;
480 
481 	init_completion(&ch->done);
482 	ret = ib_post_recv(ch->qp, &wr, &bad_wr);
483 	WARN_ONCE(ret, "ib_post_recv() returned %d\n", ret);
484 	if (ret == 0)
485 		wait_for_completion(&ch->done);
486 
487 out:
488 	ib_destroy_qp(ch->qp);
489 }
490 
491 static int srp_create_ch_ib(struct srp_rdma_ch *ch)
492 {
493 	struct srp_target_port *target = ch->target;
494 	struct srp_device *dev = target->srp_host->srp_dev;
495 	struct ib_qp_init_attr *init_attr;
496 	struct ib_cq *recv_cq, *send_cq;
497 	struct ib_qp *qp;
498 	struct ib_fmr_pool *fmr_pool = NULL;
499 	struct srp_fr_pool *fr_pool = NULL;
500 	const int m = 1 + dev->use_fast_reg;
501 	struct ib_cq_init_attr cq_attr = {};
502 	int ret;
503 
504 	init_attr = kzalloc(sizeof *init_attr, GFP_KERNEL);
505 	if (!init_attr)
506 		return -ENOMEM;
507 
508 	/* + 1 for SRP_LAST_WR_ID */
509 	cq_attr.cqe = target->queue_size + 1;
510 	cq_attr.comp_vector = ch->comp_vector;
511 	recv_cq = ib_create_cq(dev->dev, srp_recv_completion, NULL, ch,
512 			       &cq_attr);
513 	if (IS_ERR(recv_cq)) {
514 		ret = PTR_ERR(recv_cq);
515 		goto err;
516 	}
517 
518 	cq_attr.cqe = m * target->queue_size;
519 	cq_attr.comp_vector = ch->comp_vector;
520 	send_cq = ib_create_cq(dev->dev, srp_send_completion, NULL, ch,
521 			       &cq_attr);
522 	if (IS_ERR(send_cq)) {
523 		ret = PTR_ERR(send_cq);
524 		goto err_recv_cq;
525 	}
526 
527 	ib_req_notify_cq(recv_cq, IB_CQ_NEXT_COMP);
528 
529 	init_attr->event_handler       = srp_qp_event;
530 	init_attr->cap.max_send_wr     = m * target->queue_size;
531 	init_attr->cap.max_recv_wr     = target->queue_size + 1;
532 	init_attr->cap.max_recv_sge    = 1;
533 	init_attr->cap.max_send_sge    = 1;
534 	init_attr->sq_sig_type         = IB_SIGNAL_REQ_WR;
535 	init_attr->qp_type             = IB_QPT_RC;
536 	init_attr->send_cq             = send_cq;
537 	init_attr->recv_cq             = recv_cq;
538 
539 	qp = ib_create_qp(dev->pd, init_attr);
540 	if (IS_ERR(qp)) {
541 		ret = PTR_ERR(qp);
542 		goto err_send_cq;
543 	}
544 
545 	ret = srp_init_qp(target, qp);
546 	if (ret)
547 		goto err_qp;
548 
549 	if (dev->use_fast_reg) {
550 		fr_pool = srp_alloc_fr_pool(target);
551 		if (IS_ERR(fr_pool)) {
552 			ret = PTR_ERR(fr_pool);
553 			shost_printk(KERN_WARNING, target->scsi_host, PFX
554 				     "FR pool allocation failed (%d)\n", ret);
555 			goto err_qp;
556 		}
557 	} else if (dev->use_fmr) {
558 		fmr_pool = srp_alloc_fmr_pool(target);
559 		if (IS_ERR(fmr_pool)) {
560 			ret = PTR_ERR(fmr_pool);
561 			shost_printk(KERN_WARNING, target->scsi_host, PFX
562 				     "FMR pool allocation failed (%d)\n", ret);
563 			goto err_qp;
564 		}
565 	}
566 
567 	if (ch->qp)
568 		srp_destroy_qp(ch);
569 	if (ch->recv_cq)
570 		ib_destroy_cq(ch->recv_cq);
571 	if (ch->send_cq)
572 		ib_destroy_cq(ch->send_cq);
573 
574 	ch->qp = qp;
575 	ch->recv_cq = recv_cq;
576 	ch->send_cq = send_cq;
577 
578 	if (dev->use_fast_reg) {
579 		if (ch->fr_pool)
580 			srp_destroy_fr_pool(ch->fr_pool);
581 		ch->fr_pool = fr_pool;
582 	} else if (dev->use_fmr) {
583 		if (ch->fmr_pool)
584 			ib_destroy_fmr_pool(ch->fmr_pool);
585 		ch->fmr_pool = fmr_pool;
586 	}
587 
588 	kfree(init_attr);
589 	return 0;
590 
591 err_qp:
592 	ib_destroy_qp(qp);
593 
594 err_send_cq:
595 	ib_destroy_cq(send_cq);
596 
597 err_recv_cq:
598 	ib_destroy_cq(recv_cq);
599 
600 err:
601 	kfree(init_attr);
602 	return ret;
603 }
604 
605 /*
606  * Note: this function may be called without srp_alloc_iu_bufs() having been
607  * invoked. Hence the ch->[rt]x_ring checks.
608  */
609 static void srp_free_ch_ib(struct srp_target_port *target,
610 			   struct srp_rdma_ch *ch)
611 {
612 	struct srp_device *dev = target->srp_host->srp_dev;
613 	int i;
614 
615 	if (!ch->target)
616 		return;
617 
618 	if (ch->cm_id) {
619 		ib_destroy_cm_id(ch->cm_id);
620 		ch->cm_id = NULL;
621 	}
622 
623 	/* If srp_new_cm_id() succeeded but srp_create_ch_ib() not, return. */
624 	if (!ch->qp)
625 		return;
626 
627 	if (dev->use_fast_reg) {
628 		if (ch->fr_pool)
629 			srp_destroy_fr_pool(ch->fr_pool);
630 	} else if (dev->use_fmr) {
631 		if (ch->fmr_pool)
632 			ib_destroy_fmr_pool(ch->fmr_pool);
633 	}
634 	srp_destroy_qp(ch);
635 	ib_destroy_cq(ch->send_cq);
636 	ib_destroy_cq(ch->recv_cq);
637 
638 	/*
639 	 * Avoid that the SCSI error handler tries to use this channel after
640 	 * it has been freed. The SCSI error handler can namely continue
641 	 * trying to perform recovery actions after scsi_remove_host()
642 	 * returned.
643 	 */
644 	ch->target = NULL;
645 
646 	ch->qp = NULL;
647 	ch->send_cq = ch->recv_cq = NULL;
648 
649 	if (ch->rx_ring) {
650 		for (i = 0; i < target->queue_size; ++i)
651 			srp_free_iu(target->srp_host, ch->rx_ring[i]);
652 		kfree(ch->rx_ring);
653 		ch->rx_ring = NULL;
654 	}
655 	if (ch->tx_ring) {
656 		for (i = 0; i < target->queue_size; ++i)
657 			srp_free_iu(target->srp_host, ch->tx_ring[i]);
658 		kfree(ch->tx_ring);
659 		ch->tx_ring = NULL;
660 	}
661 }
662 
663 static void srp_path_rec_completion(int status,
664 				    struct ib_sa_path_rec *pathrec,
665 				    void *ch_ptr)
666 {
667 	struct srp_rdma_ch *ch = ch_ptr;
668 	struct srp_target_port *target = ch->target;
669 
670 	ch->status = status;
671 	if (status)
672 		shost_printk(KERN_ERR, target->scsi_host,
673 			     PFX "Got failed path rec status %d\n", status);
674 	else
675 		ch->path = *pathrec;
676 	complete(&ch->done);
677 }
678 
679 static int srp_lookup_path(struct srp_rdma_ch *ch)
680 {
681 	struct srp_target_port *target = ch->target;
682 	int ret;
683 
684 	ch->path.numb_path = 1;
685 
686 	init_completion(&ch->done);
687 
688 	ch->path_query_id = ib_sa_path_rec_get(&srp_sa_client,
689 					       target->srp_host->srp_dev->dev,
690 					       target->srp_host->port,
691 					       &ch->path,
692 					       IB_SA_PATH_REC_SERVICE_ID |
693 					       IB_SA_PATH_REC_DGID	 |
694 					       IB_SA_PATH_REC_SGID	 |
695 					       IB_SA_PATH_REC_NUMB_PATH	 |
696 					       IB_SA_PATH_REC_PKEY,
697 					       SRP_PATH_REC_TIMEOUT_MS,
698 					       GFP_KERNEL,
699 					       srp_path_rec_completion,
700 					       ch, &ch->path_query);
701 	if (ch->path_query_id < 0)
702 		return ch->path_query_id;
703 
704 	ret = wait_for_completion_interruptible(&ch->done);
705 	if (ret < 0)
706 		return ret;
707 
708 	if (ch->status < 0)
709 		shost_printk(KERN_WARNING, target->scsi_host,
710 			     PFX "Path record query failed\n");
711 
712 	return ch->status;
713 }
714 
715 static int srp_send_req(struct srp_rdma_ch *ch, bool multich)
716 {
717 	struct srp_target_port *target = ch->target;
718 	struct {
719 		struct ib_cm_req_param param;
720 		struct srp_login_req   priv;
721 	} *req = NULL;
722 	int status;
723 
724 	req = kzalloc(sizeof *req, GFP_KERNEL);
725 	if (!req)
726 		return -ENOMEM;
727 
728 	req->param.primary_path		      = &ch->path;
729 	req->param.alternate_path 	      = NULL;
730 	req->param.service_id 		      = target->service_id;
731 	req->param.qp_num		      = ch->qp->qp_num;
732 	req->param.qp_type		      = ch->qp->qp_type;
733 	req->param.private_data 	      = &req->priv;
734 	req->param.private_data_len 	      = sizeof req->priv;
735 	req->param.flow_control 	      = 1;
736 
737 	get_random_bytes(&req->param.starting_psn, 4);
738 	req->param.starting_psn 	     &= 0xffffff;
739 
740 	/*
741 	 * Pick some arbitrary defaults here; we could make these
742 	 * module parameters if anyone cared about setting them.
743 	 */
744 	req->param.responder_resources	      = 4;
745 	req->param.remote_cm_response_timeout = 20;
746 	req->param.local_cm_response_timeout  = 20;
747 	req->param.retry_count                = target->tl_retry_count;
748 	req->param.rnr_retry_count 	      = 7;
749 	req->param.max_cm_retries 	      = 15;
750 
751 	req->priv.opcode     	= SRP_LOGIN_REQ;
752 	req->priv.tag        	= 0;
753 	req->priv.req_it_iu_len = cpu_to_be32(target->max_iu_len);
754 	req->priv.req_buf_fmt 	= cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
755 					      SRP_BUF_FORMAT_INDIRECT);
756 	req->priv.req_flags	= (multich ? SRP_MULTICHAN_MULTI :
757 				   SRP_MULTICHAN_SINGLE);
758 	/*
759 	 * In the published SRP specification (draft rev. 16a), the
760 	 * port identifier format is 8 bytes of ID extension followed
761 	 * by 8 bytes of GUID.  Older drafts put the two halves in the
762 	 * opposite order, so that the GUID comes first.
763 	 *
764 	 * Targets conforming to these obsolete drafts can be
765 	 * recognized by the I/O Class they report.
766 	 */
767 	if (target->io_class == SRP_REV10_IB_IO_CLASS) {
768 		memcpy(req->priv.initiator_port_id,
769 		       &target->sgid.global.interface_id, 8);
770 		memcpy(req->priv.initiator_port_id + 8,
771 		       &target->initiator_ext, 8);
772 		memcpy(req->priv.target_port_id,     &target->ioc_guid, 8);
773 		memcpy(req->priv.target_port_id + 8, &target->id_ext, 8);
774 	} else {
775 		memcpy(req->priv.initiator_port_id,
776 		       &target->initiator_ext, 8);
777 		memcpy(req->priv.initiator_port_id + 8,
778 		       &target->sgid.global.interface_id, 8);
779 		memcpy(req->priv.target_port_id,     &target->id_ext, 8);
780 		memcpy(req->priv.target_port_id + 8, &target->ioc_guid, 8);
781 	}
782 
783 	/*
784 	 * Topspin/Cisco SRP targets will reject our login unless we
785 	 * zero out the first 8 bytes of our initiator port ID and set
786 	 * the second 8 bytes to the local node GUID.
787 	 */
788 	if (srp_target_is_topspin(target)) {
789 		shost_printk(KERN_DEBUG, target->scsi_host,
790 			     PFX "Topspin/Cisco initiator port ID workaround "
791 			     "activated for target GUID %016llx\n",
792 			     be64_to_cpu(target->ioc_guid));
793 		memset(req->priv.initiator_port_id, 0, 8);
794 		memcpy(req->priv.initiator_port_id + 8,
795 		       &target->srp_host->srp_dev->dev->node_guid, 8);
796 	}
797 
798 	status = ib_send_cm_req(ch->cm_id, &req->param);
799 
800 	kfree(req);
801 
802 	return status;
803 }
804 
805 static bool srp_queue_remove_work(struct srp_target_port *target)
806 {
807 	bool changed = false;
808 
809 	spin_lock_irq(&target->lock);
810 	if (target->state != SRP_TARGET_REMOVED) {
811 		target->state = SRP_TARGET_REMOVED;
812 		changed = true;
813 	}
814 	spin_unlock_irq(&target->lock);
815 
816 	if (changed)
817 		queue_work(srp_remove_wq, &target->remove_work);
818 
819 	return changed;
820 }
821 
822 static void srp_disconnect_target(struct srp_target_port *target)
823 {
824 	struct srp_rdma_ch *ch;
825 	int i;
826 
827 	/* XXX should send SRP_I_LOGOUT request */
828 
829 	for (i = 0; i < target->ch_count; i++) {
830 		ch = &target->ch[i];
831 		ch->connected = false;
832 		if (ch->cm_id && ib_send_cm_dreq(ch->cm_id, NULL, 0)) {
833 			shost_printk(KERN_DEBUG, target->scsi_host,
834 				     PFX "Sending CM DREQ failed\n");
835 		}
836 	}
837 }
838 
839 static void srp_free_req_data(struct srp_target_port *target,
840 			      struct srp_rdma_ch *ch)
841 {
842 	struct srp_device *dev = target->srp_host->srp_dev;
843 	struct ib_device *ibdev = dev->dev;
844 	struct srp_request *req;
845 	int i;
846 
847 	if (!ch->req_ring)
848 		return;
849 
850 	for (i = 0; i < target->req_ring_size; ++i) {
851 		req = &ch->req_ring[i];
852 		if (dev->use_fast_reg)
853 			kfree(req->fr_list);
854 		else
855 			kfree(req->fmr_list);
856 		kfree(req->map_page);
857 		if (req->indirect_dma_addr) {
858 			ib_dma_unmap_single(ibdev, req->indirect_dma_addr,
859 					    target->indirect_size,
860 					    DMA_TO_DEVICE);
861 		}
862 		kfree(req->indirect_desc);
863 	}
864 
865 	kfree(ch->req_ring);
866 	ch->req_ring = NULL;
867 }
868 
869 static int srp_alloc_req_data(struct srp_rdma_ch *ch)
870 {
871 	struct srp_target_port *target = ch->target;
872 	struct srp_device *srp_dev = target->srp_host->srp_dev;
873 	struct ib_device *ibdev = srp_dev->dev;
874 	struct srp_request *req;
875 	void *mr_list;
876 	dma_addr_t dma_addr;
877 	int i, ret = -ENOMEM;
878 
879 	ch->req_ring = kcalloc(target->req_ring_size, sizeof(*ch->req_ring),
880 			       GFP_KERNEL);
881 	if (!ch->req_ring)
882 		goto out;
883 
884 	for (i = 0; i < target->req_ring_size; ++i) {
885 		req = &ch->req_ring[i];
886 		mr_list = kmalloc(target->cmd_sg_cnt * sizeof(void *),
887 				  GFP_KERNEL);
888 		if (!mr_list)
889 			goto out;
890 		if (srp_dev->use_fast_reg)
891 			req->fr_list = mr_list;
892 		else
893 			req->fmr_list = mr_list;
894 		req->map_page = kmalloc(srp_dev->max_pages_per_mr *
895 					sizeof(void *), GFP_KERNEL);
896 		if (!req->map_page)
897 			goto out;
898 		req->indirect_desc = kmalloc(target->indirect_size, GFP_KERNEL);
899 		if (!req->indirect_desc)
900 			goto out;
901 
902 		dma_addr = ib_dma_map_single(ibdev, req->indirect_desc,
903 					     target->indirect_size,
904 					     DMA_TO_DEVICE);
905 		if (ib_dma_mapping_error(ibdev, dma_addr))
906 			goto out;
907 
908 		req->indirect_dma_addr = dma_addr;
909 	}
910 	ret = 0;
911 
912 out:
913 	return ret;
914 }
915 
916 /**
917  * srp_del_scsi_host_attr() - Remove attributes defined in the host template.
918  * @shost: SCSI host whose attributes to remove from sysfs.
919  *
920  * Note: Any attributes defined in the host template and that did not exist
921  * before invocation of this function will be ignored.
922  */
923 static void srp_del_scsi_host_attr(struct Scsi_Host *shost)
924 {
925 	struct device_attribute **attr;
926 
927 	for (attr = shost->hostt->shost_attrs; attr && *attr; ++attr)
928 		device_remove_file(&shost->shost_dev, *attr);
929 }
930 
931 static void srp_remove_target(struct srp_target_port *target)
932 {
933 	struct srp_rdma_ch *ch;
934 	int i;
935 
936 	WARN_ON_ONCE(target->state != SRP_TARGET_REMOVED);
937 
938 	srp_del_scsi_host_attr(target->scsi_host);
939 	srp_rport_get(target->rport);
940 	srp_remove_host(target->scsi_host);
941 	scsi_remove_host(target->scsi_host);
942 	srp_stop_rport_timers(target->rport);
943 	srp_disconnect_target(target);
944 	for (i = 0; i < target->ch_count; i++) {
945 		ch = &target->ch[i];
946 		srp_free_ch_ib(target, ch);
947 	}
948 	cancel_work_sync(&target->tl_err_work);
949 	srp_rport_put(target->rport);
950 	for (i = 0; i < target->ch_count; i++) {
951 		ch = &target->ch[i];
952 		srp_free_req_data(target, ch);
953 	}
954 	kfree(target->ch);
955 	target->ch = NULL;
956 
957 	spin_lock(&target->srp_host->target_lock);
958 	list_del(&target->list);
959 	spin_unlock(&target->srp_host->target_lock);
960 
961 	scsi_host_put(target->scsi_host);
962 }
963 
964 static void srp_remove_work(struct work_struct *work)
965 {
966 	struct srp_target_port *target =
967 		container_of(work, struct srp_target_port, remove_work);
968 
969 	WARN_ON_ONCE(target->state != SRP_TARGET_REMOVED);
970 
971 	srp_remove_target(target);
972 }
973 
974 static void srp_rport_delete(struct srp_rport *rport)
975 {
976 	struct srp_target_port *target = rport->lld_data;
977 
978 	srp_queue_remove_work(target);
979 }
980 
981 /**
982  * srp_connected_ch() - number of connected channels
983  * @target: SRP target port.
984  */
985 static int srp_connected_ch(struct srp_target_port *target)
986 {
987 	int i, c = 0;
988 
989 	for (i = 0; i < target->ch_count; i++)
990 		c += target->ch[i].connected;
991 
992 	return c;
993 }
994 
995 static int srp_connect_ch(struct srp_rdma_ch *ch, bool multich)
996 {
997 	struct srp_target_port *target = ch->target;
998 	int ret;
999 
1000 	WARN_ON_ONCE(!multich && srp_connected_ch(target) > 0);
1001 
1002 	ret = srp_lookup_path(ch);
1003 	if (ret)
1004 		return ret;
1005 
1006 	while (1) {
1007 		init_completion(&ch->done);
1008 		ret = srp_send_req(ch, multich);
1009 		if (ret)
1010 			return ret;
1011 		ret = wait_for_completion_interruptible(&ch->done);
1012 		if (ret < 0)
1013 			return ret;
1014 
1015 		/*
1016 		 * The CM event handling code will set status to
1017 		 * SRP_PORT_REDIRECT if we get a port redirect REJ
1018 		 * back, or SRP_DLID_REDIRECT if we get a lid/qp
1019 		 * redirect REJ back.
1020 		 */
1021 		switch (ch->status) {
1022 		case 0:
1023 			ch->connected = true;
1024 			return 0;
1025 
1026 		case SRP_PORT_REDIRECT:
1027 			ret = srp_lookup_path(ch);
1028 			if (ret)
1029 				return ret;
1030 			break;
1031 
1032 		case SRP_DLID_REDIRECT:
1033 			break;
1034 
1035 		case SRP_STALE_CONN:
1036 			shost_printk(KERN_ERR, target->scsi_host, PFX
1037 				     "giving up on stale connection\n");
1038 			ch->status = -ECONNRESET;
1039 			return ch->status;
1040 
1041 		default:
1042 			return ch->status;
1043 		}
1044 	}
1045 }
1046 
1047 static int srp_inv_rkey(struct srp_rdma_ch *ch, u32 rkey)
1048 {
1049 	struct ib_send_wr *bad_wr;
1050 	struct ib_send_wr wr = {
1051 		.opcode		    = IB_WR_LOCAL_INV,
1052 		.wr_id		    = LOCAL_INV_WR_ID_MASK,
1053 		.next		    = NULL,
1054 		.num_sge	    = 0,
1055 		.send_flags	    = 0,
1056 		.ex.invalidate_rkey = rkey,
1057 	};
1058 
1059 	return ib_post_send(ch->qp, &wr, &bad_wr);
1060 }
1061 
1062 static void srp_unmap_data(struct scsi_cmnd *scmnd,
1063 			   struct srp_rdma_ch *ch,
1064 			   struct srp_request *req)
1065 {
1066 	struct srp_target_port *target = ch->target;
1067 	struct srp_device *dev = target->srp_host->srp_dev;
1068 	struct ib_device *ibdev = dev->dev;
1069 	int i, res;
1070 
1071 	if (!scsi_sglist(scmnd) ||
1072 	    (scmnd->sc_data_direction != DMA_TO_DEVICE &&
1073 	     scmnd->sc_data_direction != DMA_FROM_DEVICE))
1074 		return;
1075 
1076 	if (dev->use_fast_reg) {
1077 		struct srp_fr_desc **pfr;
1078 
1079 		for (i = req->nmdesc, pfr = req->fr_list; i > 0; i--, pfr++) {
1080 			res = srp_inv_rkey(ch, (*pfr)->mr->rkey);
1081 			if (res < 0) {
1082 				shost_printk(KERN_ERR, target->scsi_host, PFX
1083 				  "Queueing INV WR for rkey %#x failed (%d)\n",
1084 				  (*pfr)->mr->rkey, res);
1085 				queue_work(system_long_wq,
1086 					   &target->tl_err_work);
1087 			}
1088 		}
1089 		if (req->nmdesc)
1090 			srp_fr_pool_put(ch->fr_pool, req->fr_list,
1091 					req->nmdesc);
1092 	} else if (dev->use_fmr) {
1093 		struct ib_pool_fmr **pfmr;
1094 
1095 		for (i = req->nmdesc, pfmr = req->fmr_list; i > 0; i--, pfmr++)
1096 			ib_fmr_pool_unmap(*pfmr);
1097 	}
1098 
1099 	ib_dma_unmap_sg(ibdev, scsi_sglist(scmnd), scsi_sg_count(scmnd),
1100 			scmnd->sc_data_direction);
1101 }
1102 
1103 /**
1104  * srp_claim_req - Take ownership of the scmnd associated with a request.
1105  * @ch: SRP RDMA channel.
1106  * @req: SRP request.
1107  * @sdev: If not NULL, only take ownership for this SCSI device.
1108  * @scmnd: If NULL, take ownership of @req->scmnd. If not NULL, only take
1109  *         ownership of @req->scmnd if it equals @scmnd.
1110  *
1111  * Return value:
1112  * Either NULL or a pointer to the SCSI command the caller became owner of.
1113  */
1114 static struct scsi_cmnd *srp_claim_req(struct srp_rdma_ch *ch,
1115 				       struct srp_request *req,
1116 				       struct scsi_device *sdev,
1117 				       struct scsi_cmnd *scmnd)
1118 {
1119 	unsigned long flags;
1120 
1121 	spin_lock_irqsave(&ch->lock, flags);
1122 	if (req->scmnd &&
1123 	    (!sdev || req->scmnd->device == sdev) &&
1124 	    (!scmnd || req->scmnd == scmnd)) {
1125 		scmnd = req->scmnd;
1126 		req->scmnd = NULL;
1127 	} else {
1128 		scmnd = NULL;
1129 	}
1130 	spin_unlock_irqrestore(&ch->lock, flags);
1131 
1132 	return scmnd;
1133 }
1134 
1135 /**
1136  * srp_free_req() - Unmap data and add request to the free request list.
1137  * @ch:     SRP RDMA channel.
1138  * @req:    Request to be freed.
1139  * @scmnd:  SCSI command associated with @req.
1140  * @req_lim_delta: Amount to be added to @target->req_lim.
1141  */
1142 static void srp_free_req(struct srp_rdma_ch *ch, struct srp_request *req,
1143 			 struct scsi_cmnd *scmnd, s32 req_lim_delta)
1144 {
1145 	unsigned long flags;
1146 
1147 	srp_unmap_data(scmnd, ch, req);
1148 
1149 	spin_lock_irqsave(&ch->lock, flags);
1150 	ch->req_lim += req_lim_delta;
1151 	spin_unlock_irqrestore(&ch->lock, flags);
1152 }
1153 
1154 static void srp_finish_req(struct srp_rdma_ch *ch, struct srp_request *req,
1155 			   struct scsi_device *sdev, int result)
1156 {
1157 	struct scsi_cmnd *scmnd = srp_claim_req(ch, req, sdev, NULL);
1158 
1159 	if (scmnd) {
1160 		srp_free_req(ch, req, scmnd, 0);
1161 		scmnd->result = result;
1162 		scmnd->scsi_done(scmnd);
1163 	}
1164 }
1165 
1166 static void srp_terminate_io(struct srp_rport *rport)
1167 {
1168 	struct srp_target_port *target = rport->lld_data;
1169 	struct srp_rdma_ch *ch;
1170 	struct Scsi_Host *shost = target->scsi_host;
1171 	struct scsi_device *sdev;
1172 	int i, j;
1173 
1174 	/*
1175 	 * Invoking srp_terminate_io() while srp_queuecommand() is running
1176 	 * is not safe. Hence the warning statement below.
1177 	 */
1178 	shost_for_each_device(sdev, shost)
1179 		WARN_ON_ONCE(sdev->request_queue->request_fn_active);
1180 
1181 	for (i = 0; i < target->ch_count; i++) {
1182 		ch = &target->ch[i];
1183 
1184 		for (j = 0; j < target->req_ring_size; ++j) {
1185 			struct srp_request *req = &ch->req_ring[j];
1186 
1187 			srp_finish_req(ch, req, NULL,
1188 				       DID_TRANSPORT_FAILFAST << 16);
1189 		}
1190 	}
1191 }
1192 
1193 /*
1194  * It is up to the caller to ensure that srp_rport_reconnect() calls are
1195  * serialized and that no concurrent srp_queuecommand(), srp_abort(),
1196  * srp_reset_device() or srp_reset_host() calls will occur while this function
1197  * is in progress. One way to realize that is not to call this function
1198  * directly but to call srp_reconnect_rport() instead since that last function
1199  * serializes calls of this function via rport->mutex and also blocks
1200  * srp_queuecommand() calls before invoking this function.
1201  */
1202 static int srp_rport_reconnect(struct srp_rport *rport)
1203 {
1204 	struct srp_target_port *target = rport->lld_data;
1205 	struct srp_rdma_ch *ch;
1206 	int i, j, ret = 0;
1207 	bool multich = false;
1208 
1209 	srp_disconnect_target(target);
1210 
1211 	if (target->state == SRP_TARGET_SCANNING)
1212 		return -ENODEV;
1213 
1214 	/*
1215 	 * Now get a new local CM ID so that we avoid confusing the target in
1216 	 * case things are really fouled up. Doing so also ensures that all CM
1217 	 * callbacks will have finished before a new QP is allocated.
1218 	 */
1219 	for (i = 0; i < target->ch_count; i++) {
1220 		ch = &target->ch[i];
1221 		ret += srp_new_cm_id(ch);
1222 	}
1223 	for (i = 0; i < target->ch_count; i++) {
1224 		ch = &target->ch[i];
1225 		for (j = 0; j < target->req_ring_size; ++j) {
1226 			struct srp_request *req = &ch->req_ring[j];
1227 
1228 			srp_finish_req(ch, req, NULL, DID_RESET << 16);
1229 		}
1230 	}
1231 	for (i = 0; i < target->ch_count; i++) {
1232 		ch = &target->ch[i];
1233 		/*
1234 		 * Whether or not creating a new CM ID succeeded, create a new
1235 		 * QP. This guarantees that all completion callback function
1236 		 * invocations have finished before request resetting starts.
1237 		 */
1238 		ret += srp_create_ch_ib(ch);
1239 
1240 		INIT_LIST_HEAD(&ch->free_tx);
1241 		for (j = 0; j < target->queue_size; ++j)
1242 			list_add(&ch->tx_ring[j]->list, &ch->free_tx);
1243 	}
1244 
1245 	target->qp_in_error = false;
1246 
1247 	for (i = 0; i < target->ch_count; i++) {
1248 		ch = &target->ch[i];
1249 		if (ret)
1250 			break;
1251 		ret = srp_connect_ch(ch, multich);
1252 		multich = true;
1253 	}
1254 
1255 	if (ret == 0)
1256 		shost_printk(KERN_INFO, target->scsi_host,
1257 			     PFX "reconnect succeeded\n");
1258 
1259 	return ret;
1260 }
1261 
1262 static void srp_map_desc(struct srp_map_state *state, dma_addr_t dma_addr,
1263 			 unsigned int dma_len, u32 rkey)
1264 {
1265 	struct srp_direct_buf *desc = state->desc;
1266 
1267 	WARN_ON_ONCE(!dma_len);
1268 
1269 	desc->va = cpu_to_be64(dma_addr);
1270 	desc->key = cpu_to_be32(rkey);
1271 	desc->len = cpu_to_be32(dma_len);
1272 
1273 	state->total_len += dma_len;
1274 	state->desc++;
1275 	state->ndesc++;
1276 }
1277 
1278 static int srp_map_finish_fmr(struct srp_map_state *state,
1279 			      struct srp_rdma_ch *ch)
1280 {
1281 	struct srp_target_port *target = ch->target;
1282 	struct srp_device *dev = target->srp_host->srp_dev;
1283 	struct ib_pool_fmr *fmr;
1284 	u64 io_addr = 0;
1285 
1286 	if (state->fmr.next >= state->fmr.end)
1287 		return -ENOMEM;
1288 
1289 	fmr = ib_fmr_pool_map_phys(ch->fmr_pool, state->pages,
1290 				   state->npages, io_addr);
1291 	if (IS_ERR(fmr))
1292 		return PTR_ERR(fmr);
1293 
1294 	*state->fmr.next++ = fmr;
1295 	state->nmdesc++;
1296 
1297 	srp_map_desc(state, state->base_dma_addr & ~dev->mr_page_mask,
1298 		     state->dma_len, fmr->fmr->rkey);
1299 
1300 	return 0;
1301 }
1302 
1303 static int srp_map_finish_fr(struct srp_map_state *state,
1304 			     struct srp_rdma_ch *ch)
1305 {
1306 	struct srp_target_port *target = ch->target;
1307 	struct srp_device *dev = target->srp_host->srp_dev;
1308 	struct ib_send_wr *bad_wr;
1309 	struct ib_send_wr wr;
1310 	struct srp_fr_desc *desc;
1311 	u32 rkey;
1312 
1313 	if (state->fr.next >= state->fr.end)
1314 		return -ENOMEM;
1315 
1316 	desc = srp_fr_pool_get(ch->fr_pool);
1317 	if (!desc)
1318 		return -ENOMEM;
1319 
1320 	rkey = ib_inc_rkey(desc->mr->rkey);
1321 	ib_update_fast_reg_key(desc->mr, rkey);
1322 
1323 	memcpy(desc->frpl->page_list, state->pages,
1324 	       sizeof(state->pages[0]) * state->npages);
1325 
1326 	memset(&wr, 0, sizeof(wr));
1327 	wr.opcode = IB_WR_FAST_REG_MR;
1328 	wr.wr_id = FAST_REG_WR_ID_MASK;
1329 	wr.wr.fast_reg.iova_start = state->base_dma_addr;
1330 	wr.wr.fast_reg.page_list = desc->frpl;
1331 	wr.wr.fast_reg.page_list_len = state->npages;
1332 	wr.wr.fast_reg.page_shift = ilog2(dev->mr_page_size);
1333 	wr.wr.fast_reg.length = state->dma_len;
1334 	wr.wr.fast_reg.access_flags = (IB_ACCESS_LOCAL_WRITE |
1335 				       IB_ACCESS_REMOTE_READ |
1336 				       IB_ACCESS_REMOTE_WRITE);
1337 	wr.wr.fast_reg.rkey = desc->mr->lkey;
1338 
1339 	*state->fr.next++ = desc;
1340 	state->nmdesc++;
1341 
1342 	srp_map_desc(state, state->base_dma_addr, state->dma_len,
1343 		     desc->mr->rkey);
1344 
1345 	return ib_post_send(ch->qp, &wr, &bad_wr);
1346 }
1347 
1348 static int srp_finish_mapping(struct srp_map_state *state,
1349 			      struct srp_rdma_ch *ch)
1350 {
1351 	struct srp_target_port *target = ch->target;
1352 	struct srp_device *dev = target->srp_host->srp_dev;
1353 	int ret = 0;
1354 
1355 	WARN_ON_ONCE(!dev->use_fast_reg && !dev->use_fmr);
1356 
1357 	if (state->npages == 0)
1358 		return 0;
1359 
1360 	if (state->npages == 1 && target->global_mr)
1361 		srp_map_desc(state, state->base_dma_addr, state->dma_len,
1362 			     target->global_mr->rkey);
1363 	else
1364 		ret = dev->use_fast_reg ? srp_map_finish_fr(state, ch) :
1365 			srp_map_finish_fmr(state, ch);
1366 
1367 	if (ret == 0) {
1368 		state->npages = 0;
1369 		state->dma_len = 0;
1370 	}
1371 
1372 	return ret;
1373 }
1374 
1375 static int srp_map_sg_entry(struct srp_map_state *state,
1376 			    struct srp_rdma_ch *ch,
1377 			    struct scatterlist *sg, int sg_index)
1378 {
1379 	struct srp_target_port *target = ch->target;
1380 	struct srp_device *dev = target->srp_host->srp_dev;
1381 	struct ib_device *ibdev = dev->dev;
1382 	dma_addr_t dma_addr = ib_sg_dma_address(ibdev, sg);
1383 	unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
1384 	unsigned int len = 0;
1385 	int ret;
1386 
1387 	WARN_ON_ONCE(!dma_len);
1388 
1389 	while (dma_len) {
1390 		unsigned offset = dma_addr & ~dev->mr_page_mask;
1391 		if (state->npages == dev->max_pages_per_mr || offset != 0) {
1392 			ret = srp_finish_mapping(state, ch);
1393 			if (ret)
1394 				return ret;
1395 		}
1396 
1397 		len = min_t(unsigned int, dma_len, dev->mr_page_size - offset);
1398 
1399 		if (!state->npages)
1400 			state->base_dma_addr = dma_addr;
1401 		state->pages[state->npages++] = dma_addr & dev->mr_page_mask;
1402 		state->dma_len += len;
1403 		dma_addr += len;
1404 		dma_len -= len;
1405 	}
1406 
1407 	/*
1408 	 * If the last entry of the MR wasn't a full page, then we need to
1409 	 * close it out and start a new one -- we can only merge at page
1410 	 * boundries.
1411 	 */
1412 	ret = 0;
1413 	if (len != dev->mr_page_size)
1414 		ret = srp_finish_mapping(state, ch);
1415 	return ret;
1416 }
1417 
1418 static int srp_map_sg(struct srp_map_state *state, struct srp_rdma_ch *ch,
1419 		      struct srp_request *req, struct scatterlist *scat,
1420 		      int count)
1421 {
1422 	struct srp_target_port *target = ch->target;
1423 	struct srp_device *dev = target->srp_host->srp_dev;
1424 	struct scatterlist *sg;
1425 	int i, ret;
1426 
1427 	state->desc	= req->indirect_desc;
1428 	state->pages	= req->map_page;
1429 	if (dev->use_fast_reg) {
1430 		state->fr.next = req->fr_list;
1431 		state->fr.end = req->fr_list + target->cmd_sg_cnt;
1432 	} else if (dev->use_fmr) {
1433 		state->fmr.next = req->fmr_list;
1434 		state->fmr.end = req->fmr_list + target->cmd_sg_cnt;
1435 	}
1436 
1437 	if (dev->use_fast_reg || dev->use_fmr) {
1438 		for_each_sg(scat, sg, count, i) {
1439 			ret = srp_map_sg_entry(state, ch, sg, i);
1440 			if (ret)
1441 				goto out;
1442 		}
1443 		ret = srp_finish_mapping(state, ch);
1444 		if (ret)
1445 			goto out;
1446 	} else {
1447 		for_each_sg(scat, sg, count, i) {
1448 			srp_map_desc(state, ib_sg_dma_address(dev->dev, sg),
1449 				     ib_sg_dma_len(dev->dev, sg),
1450 				     target->global_mr->rkey);
1451 		}
1452 	}
1453 
1454 	req->nmdesc = state->nmdesc;
1455 	ret = 0;
1456 
1457 out:
1458 	return ret;
1459 }
1460 
1461 /*
1462  * Register the indirect data buffer descriptor with the HCA.
1463  *
1464  * Note: since the indirect data buffer descriptor has been allocated with
1465  * kmalloc() it is guaranteed that this buffer is a physically contiguous
1466  * memory buffer.
1467  */
1468 static int srp_map_idb(struct srp_rdma_ch *ch, struct srp_request *req,
1469 		       void **next_mr, void **end_mr, u32 idb_len,
1470 		       __be32 *idb_rkey)
1471 {
1472 	struct srp_target_port *target = ch->target;
1473 	struct srp_device *dev = target->srp_host->srp_dev;
1474 	struct srp_map_state state;
1475 	struct srp_direct_buf idb_desc;
1476 	u64 idb_pages[1];
1477 	int ret;
1478 
1479 	memset(&state, 0, sizeof(state));
1480 	memset(&idb_desc, 0, sizeof(idb_desc));
1481 	state.gen.next = next_mr;
1482 	state.gen.end = end_mr;
1483 	state.desc = &idb_desc;
1484 	state.pages = idb_pages;
1485 	state.pages[0] = (req->indirect_dma_addr &
1486 			  dev->mr_page_mask);
1487 	state.npages = 1;
1488 	state.base_dma_addr = req->indirect_dma_addr;
1489 	state.dma_len = idb_len;
1490 	ret = srp_finish_mapping(&state, ch);
1491 	if (ret < 0)
1492 		goto out;
1493 
1494 	*idb_rkey = idb_desc.key;
1495 
1496 out:
1497 	return ret;
1498 }
1499 
1500 static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch,
1501 			struct srp_request *req)
1502 {
1503 	struct srp_target_port *target = ch->target;
1504 	struct scatterlist *scat;
1505 	struct srp_cmd *cmd = req->cmd->buf;
1506 	int len, nents, count, ret;
1507 	struct srp_device *dev;
1508 	struct ib_device *ibdev;
1509 	struct srp_map_state state;
1510 	struct srp_indirect_buf *indirect_hdr;
1511 	u32 idb_len, table_len;
1512 	__be32 idb_rkey;
1513 	u8 fmt;
1514 
1515 	if (!scsi_sglist(scmnd) || scmnd->sc_data_direction == DMA_NONE)
1516 		return sizeof (struct srp_cmd);
1517 
1518 	if (scmnd->sc_data_direction != DMA_FROM_DEVICE &&
1519 	    scmnd->sc_data_direction != DMA_TO_DEVICE) {
1520 		shost_printk(KERN_WARNING, target->scsi_host,
1521 			     PFX "Unhandled data direction %d\n",
1522 			     scmnd->sc_data_direction);
1523 		return -EINVAL;
1524 	}
1525 
1526 	nents = scsi_sg_count(scmnd);
1527 	scat  = scsi_sglist(scmnd);
1528 
1529 	dev = target->srp_host->srp_dev;
1530 	ibdev = dev->dev;
1531 
1532 	count = ib_dma_map_sg(ibdev, scat, nents, scmnd->sc_data_direction);
1533 	if (unlikely(count == 0))
1534 		return -EIO;
1535 
1536 	fmt = SRP_DATA_DESC_DIRECT;
1537 	len = sizeof (struct srp_cmd) +	sizeof (struct srp_direct_buf);
1538 
1539 	if (count == 1 && target->global_mr) {
1540 		/*
1541 		 * The midlayer only generated a single gather/scatter
1542 		 * entry, or DMA mapping coalesced everything to a
1543 		 * single entry.  So a direct descriptor along with
1544 		 * the DMA MR suffices.
1545 		 */
1546 		struct srp_direct_buf *buf = (void *) cmd->add_data;
1547 
1548 		buf->va  = cpu_to_be64(ib_sg_dma_address(ibdev, scat));
1549 		buf->key = cpu_to_be32(target->global_mr->rkey);
1550 		buf->len = cpu_to_be32(ib_sg_dma_len(ibdev, scat));
1551 
1552 		req->nmdesc = 0;
1553 		goto map_complete;
1554 	}
1555 
1556 	/*
1557 	 * We have more than one scatter/gather entry, so build our indirect
1558 	 * descriptor table, trying to merge as many entries as we can.
1559 	 */
1560 	indirect_hdr = (void *) cmd->add_data;
1561 
1562 	ib_dma_sync_single_for_cpu(ibdev, req->indirect_dma_addr,
1563 				   target->indirect_size, DMA_TO_DEVICE);
1564 
1565 	memset(&state, 0, sizeof(state));
1566 	srp_map_sg(&state, ch, req, scat, count);
1567 
1568 	/* We've mapped the request, now pull as much of the indirect
1569 	 * descriptor table as we can into the command buffer. If this
1570 	 * target is not using an external indirect table, we are
1571 	 * guaranteed to fit into the command, as the SCSI layer won't
1572 	 * give us more S/G entries than we allow.
1573 	 */
1574 	if (state.ndesc == 1) {
1575 		/*
1576 		 * Memory registration collapsed the sg-list into one entry,
1577 		 * so use a direct descriptor.
1578 		 */
1579 		struct srp_direct_buf *buf = (void *) cmd->add_data;
1580 
1581 		*buf = req->indirect_desc[0];
1582 		goto map_complete;
1583 	}
1584 
1585 	if (unlikely(target->cmd_sg_cnt < state.ndesc &&
1586 						!target->allow_ext_sg)) {
1587 		shost_printk(KERN_ERR, target->scsi_host,
1588 			     "Could not fit S/G list into SRP_CMD\n");
1589 		return -EIO;
1590 	}
1591 
1592 	count = min(state.ndesc, target->cmd_sg_cnt);
1593 	table_len = state.ndesc * sizeof (struct srp_direct_buf);
1594 	idb_len = sizeof(struct srp_indirect_buf) + table_len;
1595 
1596 	fmt = SRP_DATA_DESC_INDIRECT;
1597 	len = sizeof(struct srp_cmd) + sizeof (struct srp_indirect_buf);
1598 	len += count * sizeof (struct srp_direct_buf);
1599 
1600 	memcpy(indirect_hdr->desc_list, req->indirect_desc,
1601 	       count * sizeof (struct srp_direct_buf));
1602 
1603 	if (!target->global_mr) {
1604 		ret = srp_map_idb(ch, req, state.gen.next, state.gen.end,
1605 				  idb_len, &idb_rkey);
1606 		if (ret < 0)
1607 			return ret;
1608 		req->nmdesc++;
1609 	} else {
1610 		idb_rkey = target->global_mr->rkey;
1611 	}
1612 
1613 	indirect_hdr->table_desc.va = cpu_to_be64(req->indirect_dma_addr);
1614 	indirect_hdr->table_desc.key = idb_rkey;
1615 	indirect_hdr->table_desc.len = cpu_to_be32(table_len);
1616 	indirect_hdr->len = cpu_to_be32(state.total_len);
1617 
1618 	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
1619 		cmd->data_out_desc_cnt = count;
1620 	else
1621 		cmd->data_in_desc_cnt = count;
1622 
1623 	ib_dma_sync_single_for_device(ibdev, req->indirect_dma_addr, table_len,
1624 				      DMA_TO_DEVICE);
1625 
1626 map_complete:
1627 	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
1628 		cmd->buf_fmt = fmt << 4;
1629 	else
1630 		cmd->buf_fmt = fmt;
1631 
1632 	return len;
1633 }
1634 
1635 /*
1636  * Return an IU and possible credit to the free pool
1637  */
1638 static void srp_put_tx_iu(struct srp_rdma_ch *ch, struct srp_iu *iu,
1639 			  enum srp_iu_type iu_type)
1640 {
1641 	unsigned long flags;
1642 
1643 	spin_lock_irqsave(&ch->lock, flags);
1644 	list_add(&iu->list, &ch->free_tx);
1645 	if (iu_type != SRP_IU_RSP)
1646 		++ch->req_lim;
1647 	spin_unlock_irqrestore(&ch->lock, flags);
1648 }
1649 
1650 /*
1651  * Must be called with ch->lock held to protect req_lim and free_tx.
1652  * If IU is not sent, it must be returned using srp_put_tx_iu().
1653  *
1654  * Note:
1655  * An upper limit for the number of allocated information units for each
1656  * request type is:
1657  * - SRP_IU_CMD: SRP_CMD_SQ_SIZE, since the SCSI mid-layer never queues
1658  *   more than Scsi_Host.can_queue requests.
1659  * - SRP_IU_TSK_MGMT: SRP_TSK_MGMT_SQ_SIZE.
1660  * - SRP_IU_RSP: 1, since a conforming SRP target never sends more than
1661  *   one unanswered SRP request to an initiator.
1662  */
1663 static struct srp_iu *__srp_get_tx_iu(struct srp_rdma_ch *ch,
1664 				      enum srp_iu_type iu_type)
1665 {
1666 	struct srp_target_port *target = ch->target;
1667 	s32 rsv = (iu_type == SRP_IU_TSK_MGMT) ? 0 : SRP_TSK_MGMT_SQ_SIZE;
1668 	struct srp_iu *iu;
1669 
1670 	srp_send_completion(ch->send_cq, ch);
1671 
1672 	if (list_empty(&ch->free_tx))
1673 		return NULL;
1674 
1675 	/* Initiator responses to target requests do not consume credits */
1676 	if (iu_type != SRP_IU_RSP) {
1677 		if (ch->req_lim <= rsv) {
1678 			++target->zero_req_lim;
1679 			return NULL;
1680 		}
1681 
1682 		--ch->req_lim;
1683 	}
1684 
1685 	iu = list_first_entry(&ch->free_tx, struct srp_iu, list);
1686 	list_del(&iu->list);
1687 	return iu;
1688 }
1689 
1690 static int srp_post_send(struct srp_rdma_ch *ch, struct srp_iu *iu, int len)
1691 {
1692 	struct srp_target_port *target = ch->target;
1693 	struct ib_sge list;
1694 	struct ib_send_wr wr, *bad_wr;
1695 
1696 	list.addr   = iu->dma;
1697 	list.length = len;
1698 	list.lkey   = target->lkey;
1699 
1700 	wr.next       = NULL;
1701 	wr.wr_id      = (uintptr_t) iu;
1702 	wr.sg_list    = &list;
1703 	wr.num_sge    = 1;
1704 	wr.opcode     = IB_WR_SEND;
1705 	wr.send_flags = IB_SEND_SIGNALED;
1706 
1707 	return ib_post_send(ch->qp, &wr, &bad_wr);
1708 }
1709 
1710 static int srp_post_recv(struct srp_rdma_ch *ch, struct srp_iu *iu)
1711 {
1712 	struct srp_target_port *target = ch->target;
1713 	struct ib_recv_wr wr, *bad_wr;
1714 	struct ib_sge list;
1715 
1716 	list.addr   = iu->dma;
1717 	list.length = iu->size;
1718 	list.lkey   = target->lkey;
1719 
1720 	wr.next     = NULL;
1721 	wr.wr_id    = (uintptr_t) iu;
1722 	wr.sg_list  = &list;
1723 	wr.num_sge  = 1;
1724 
1725 	return ib_post_recv(ch->qp, &wr, &bad_wr);
1726 }
1727 
1728 static void srp_process_rsp(struct srp_rdma_ch *ch, struct srp_rsp *rsp)
1729 {
1730 	struct srp_target_port *target = ch->target;
1731 	struct srp_request *req;
1732 	struct scsi_cmnd *scmnd;
1733 	unsigned long flags;
1734 
1735 	if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
1736 		spin_lock_irqsave(&ch->lock, flags);
1737 		ch->req_lim += be32_to_cpu(rsp->req_lim_delta);
1738 		spin_unlock_irqrestore(&ch->lock, flags);
1739 
1740 		ch->tsk_mgmt_status = -1;
1741 		if (be32_to_cpu(rsp->resp_data_len) >= 4)
1742 			ch->tsk_mgmt_status = rsp->data[3];
1743 		complete(&ch->tsk_mgmt_done);
1744 	} else {
1745 		scmnd = scsi_host_find_tag(target->scsi_host, rsp->tag);
1746 		if (scmnd) {
1747 			req = (void *)scmnd->host_scribble;
1748 			scmnd = srp_claim_req(ch, req, NULL, scmnd);
1749 		}
1750 		if (!scmnd) {
1751 			shost_printk(KERN_ERR, target->scsi_host,
1752 				     "Null scmnd for RSP w/tag %#016llx received on ch %td / QP %#x\n",
1753 				     rsp->tag, ch - target->ch, ch->qp->qp_num);
1754 
1755 			spin_lock_irqsave(&ch->lock, flags);
1756 			ch->req_lim += be32_to_cpu(rsp->req_lim_delta);
1757 			spin_unlock_irqrestore(&ch->lock, flags);
1758 
1759 			return;
1760 		}
1761 		scmnd->result = rsp->status;
1762 
1763 		if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
1764 			memcpy(scmnd->sense_buffer, rsp->data +
1765 			       be32_to_cpu(rsp->resp_data_len),
1766 			       min_t(int, be32_to_cpu(rsp->sense_data_len),
1767 				     SCSI_SENSE_BUFFERSIZE));
1768 		}
1769 
1770 		if (unlikely(rsp->flags & SRP_RSP_FLAG_DIUNDER))
1771 			scsi_set_resid(scmnd, be32_to_cpu(rsp->data_in_res_cnt));
1772 		else if (unlikely(rsp->flags & SRP_RSP_FLAG_DIOVER))
1773 			scsi_set_resid(scmnd, -be32_to_cpu(rsp->data_in_res_cnt));
1774 		else if (unlikely(rsp->flags & SRP_RSP_FLAG_DOUNDER))
1775 			scsi_set_resid(scmnd, be32_to_cpu(rsp->data_out_res_cnt));
1776 		else if (unlikely(rsp->flags & SRP_RSP_FLAG_DOOVER))
1777 			scsi_set_resid(scmnd, -be32_to_cpu(rsp->data_out_res_cnt));
1778 
1779 		srp_free_req(ch, req, scmnd,
1780 			     be32_to_cpu(rsp->req_lim_delta));
1781 
1782 		scmnd->host_scribble = NULL;
1783 		scmnd->scsi_done(scmnd);
1784 	}
1785 }
1786 
1787 static int srp_response_common(struct srp_rdma_ch *ch, s32 req_delta,
1788 			       void *rsp, int len)
1789 {
1790 	struct srp_target_port *target = ch->target;
1791 	struct ib_device *dev = target->srp_host->srp_dev->dev;
1792 	unsigned long flags;
1793 	struct srp_iu *iu;
1794 	int err;
1795 
1796 	spin_lock_irqsave(&ch->lock, flags);
1797 	ch->req_lim += req_delta;
1798 	iu = __srp_get_tx_iu(ch, SRP_IU_RSP);
1799 	spin_unlock_irqrestore(&ch->lock, flags);
1800 
1801 	if (!iu) {
1802 		shost_printk(KERN_ERR, target->scsi_host, PFX
1803 			     "no IU available to send response\n");
1804 		return 1;
1805 	}
1806 
1807 	ib_dma_sync_single_for_cpu(dev, iu->dma, len, DMA_TO_DEVICE);
1808 	memcpy(iu->buf, rsp, len);
1809 	ib_dma_sync_single_for_device(dev, iu->dma, len, DMA_TO_DEVICE);
1810 
1811 	err = srp_post_send(ch, iu, len);
1812 	if (err) {
1813 		shost_printk(KERN_ERR, target->scsi_host, PFX
1814 			     "unable to post response: %d\n", err);
1815 		srp_put_tx_iu(ch, iu, SRP_IU_RSP);
1816 	}
1817 
1818 	return err;
1819 }
1820 
1821 static void srp_process_cred_req(struct srp_rdma_ch *ch,
1822 				 struct srp_cred_req *req)
1823 {
1824 	struct srp_cred_rsp rsp = {
1825 		.opcode = SRP_CRED_RSP,
1826 		.tag = req->tag,
1827 	};
1828 	s32 delta = be32_to_cpu(req->req_lim_delta);
1829 
1830 	if (srp_response_common(ch, delta, &rsp, sizeof(rsp)))
1831 		shost_printk(KERN_ERR, ch->target->scsi_host, PFX
1832 			     "problems processing SRP_CRED_REQ\n");
1833 }
1834 
1835 static void srp_process_aer_req(struct srp_rdma_ch *ch,
1836 				struct srp_aer_req *req)
1837 {
1838 	struct srp_target_port *target = ch->target;
1839 	struct srp_aer_rsp rsp = {
1840 		.opcode = SRP_AER_RSP,
1841 		.tag = req->tag,
1842 	};
1843 	s32 delta = be32_to_cpu(req->req_lim_delta);
1844 
1845 	shost_printk(KERN_ERR, target->scsi_host, PFX
1846 		     "ignoring AER for LUN %llu\n", scsilun_to_int(&req->lun));
1847 
1848 	if (srp_response_common(ch, delta, &rsp, sizeof(rsp)))
1849 		shost_printk(KERN_ERR, target->scsi_host, PFX
1850 			     "problems processing SRP_AER_REQ\n");
1851 }
1852 
1853 static void srp_handle_recv(struct srp_rdma_ch *ch, struct ib_wc *wc)
1854 {
1855 	struct srp_target_port *target = ch->target;
1856 	struct ib_device *dev = target->srp_host->srp_dev->dev;
1857 	struct srp_iu *iu = (struct srp_iu *) (uintptr_t) wc->wr_id;
1858 	int res;
1859 	u8 opcode;
1860 
1861 	ib_dma_sync_single_for_cpu(dev, iu->dma, ch->max_ti_iu_len,
1862 				   DMA_FROM_DEVICE);
1863 
1864 	opcode = *(u8 *) iu->buf;
1865 
1866 	if (0) {
1867 		shost_printk(KERN_ERR, target->scsi_host,
1868 			     PFX "recv completion, opcode 0x%02x\n", opcode);
1869 		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 8, 1,
1870 			       iu->buf, wc->byte_len, true);
1871 	}
1872 
1873 	switch (opcode) {
1874 	case SRP_RSP:
1875 		srp_process_rsp(ch, iu->buf);
1876 		break;
1877 
1878 	case SRP_CRED_REQ:
1879 		srp_process_cred_req(ch, iu->buf);
1880 		break;
1881 
1882 	case SRP_AER_REQ:
1883 		srp_process_aer_req(ch, iu->buf);
1884 		break;
1885 
1886 	case SRP_T_LOGOUT:
1887 		/* XXX Handle target logout */
1888 		shost_printk(KERN_WARNING, target->scsi_host,
1889 			     PFX "Got target logout request\n");
1890 		break;
1891 
1892 	default:
1893 		shost_printk(KERN_WARNING, target->scsi_host,
1894 			     PFX "Unhandled SRP opcode 0x%02x\n", opcode);
1895 		break;
1896 	}
1897 
1898 	ib_dma_sync_single_for_device(dev, iu->dma, ch->max_ti_iu_len,
1899 				      DMA_FROM_DEVICE);
1900 
1901 	res = srp_post_recv(ch, iu);
1902 	if (res != 0)
1903 		shost_printk(KERN_ERR, target->scsi_host,
1904 			     PFX "Recv failed with error code %d\n", res);
1905 }
1906 
1907 /**
1908  * srp_tl_err_work() - handle a transport layer error
1909  * @work: Work structure embedded in an SRP target port.
1910  *
1911  * Note: This function may get invoked before the rport has been created,
1912  * hence the target->rport test.
1913  */
1914 static void srp_tl_err_work(struct work_struct *work)
1915 {
1916 	struct srp_target_port *target;
1917 
1918 	target = container_of(work, struct srp_target_port, tl_err_work);
1919 	if (target->rport)
1920 		srp_start_tl_fail_timers(target->rport);
1921 }
1922 
1923 static void srp_handle_qp_err(u64 wr_id, enum ib_wc_status wc_status,
1924 			      bool send_err, struct srp_rdma_ch *ch)
1925 {
1926 	struct srp_target_port *target = ch->target;
1927 
1928 	if (wr_id == SRP_LAST_WR_ID) {
1929 		complete(&ch->done);
1930 		return;
1931 	}
1932 
1933 	if (ch->connected && !target->qp_in_error) {
1934 		if (wr_id & LOCAL_INV_WR_ID_MASK) {
1935 			shost_printk(KERN_ERR, target->scsi_host, PFX
1936 				     "LOCAL_INV failed with status %s (%d)\n",
1937 				     ib_wc_status_msg(wc_status), wc_status);
1938 		} else if (wr_id & FAST_REG_WR_ID_MASK) {
1939 			shost_printk(KERN_ERR, target->scsi_host, PFX
1940 				     "FAST_REG_MR failed status %s (%d)\n",
1941 				     ib_wc_status_msg(wc_status), wc_status);
1942 		} else {
1943 			shost_printk(KERN_ERR, target->scsi_host,
1944 				     PFX "failed %s status %s (%d) for iu %p\n",
1945 				     send_err ? "send" : "receive",
1946 				     ib_wc_status_msg(wc_status), wc_status,
1947 				     (void *)(uintptr_t)wr_id);
1948 		}
1949 		queue_work(system_long_wq, &target->tl_err_work);
1950 	}
1951 	target->qp_in_error = true;
1952 }
1953 
1954 static void srp_recv_completion(struct ib_cq *cq, void *ch_ptr)
1955 {
1956 	struct srp_rdma_ch *ch = ch_ptr;
1957 	struct ib_wc wc;
1958 
1959 	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1960 	while (ib_poll_cq(cq, 1, &wc) > 0) {
1961 		if (likely(wc.status == IB_WC_SUCCESS)) {
1962 			srp_handle_recv(ch, &wc);
1963 		} else {
1964 			srp_handle_qp_err(wc.wr_id, wc.status, false, ch);
1965 		}
1966 	}
1967 }
1968 
1969 static void srp_send_completion(struct ib_cq *cq, void *ch_ptr)
1970 {
1971 	struct srp_rdma_ch *ch = ch_ptr;
1972 	struct ib_wc wc;
1973 	struct srp_iu *iu;
1974 
1975 	while (ib_poll_cq(cq, 1, &wc) > 0) {
1976 		if (likely(wc.status == IB_WC_SUCCESS)) {
1977 			iu = (struct srp_iu *) (uintptr_t) wc.wr_id;
1978 			list_add(&iu->list, &ch->free_tx);
1979 		} else {
1980 			srp_handle_qp_err(wc.wr_id, wc.status, true, ch);
1981 		}
1982 	}
1983 }
1984 
1985 static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
1986 {
1987 	struct srp_target_port *target = host_to_target(shost);
1988 	struct srp_rport *rport = target->rport;
1989 	struct srp_rdma_ch *ch;
1990 	struct srp_request *req;
1991 	struct srp_iu *iu;
1992 	struct srp_cmd *cmd;
1993 	struct ib_device *dev;
1994 	unsigned long flags;
1995 	u32 tag;
1996 	u16 idx;
1997 	int len, ret;
1998 	const bool in_scsi_eh = !in_interrupt() && current == shost->ehandler;
1999 
2000 	/*
2001 	 * The SCSI EH thread is the only context from which srp_queuecommand()
2002 	 * can get invoked for blocked devices (SDEV_BLOCK /
2003 	 * SDEV_CREATED_BLOCK). Avoid racing with srp_reconnect_rport() by
2004 	 * locking the rport mutex if invoked from inside the SCSI EH.
2005 	 */
2006 	if (in_scsi_eh)
2007 		mutex_lock(&rport->mutex);
2008 
2009 	scmnd->result = srp_chkready(target->rport);
2010 	if (unlikely(scmnd->result))
2011 		goto err;
2012 
2013 	WARN_ON_ONCE(scmnd->request->tag < 0);
2014 	tag = blk_mq_unique_tag(scmnd->request);
2015 	ch = &target->ch[blk_mq_unique_tag_to_hwq(tag)];
2016 	idx = blk_mq_unique_tag_to_tag(tag);
2017 	WARN_ONCE(idx >= target->req_ring_size, "%s: tag %#x: idx %d >= %d\n",
2018 		  dev_name(&shost->shost_gendev), tag, idx,
2019 		  target->req_ring_size);
2020 
2021 	spin_lock_irqsave(&ch->lock, flags);
2022 	iu = __srp_get_tx_iu(ch, SRP_IU_CMD);
2023 	spin_unlock_irqrestore(&ch->lock, flags);
2024 
2025 	if (!iu)
2026 		goto err;
2027 
2028 	req = &ch->req_ring[idx];
2029 	dev = target->srp_host->srp_dev->dev;
2030 	ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_iu_len,
2031 				   DMA_TO_DEVICE);
2032 
2033 	scmnd->host_scribble = (void *) req;
2034 
2035 	cmd = iu->buf;
2036 	memset(cmd, 0, sizeof *cmd);
2037 
2038 	cmd->opcode = SRP_CMD;
2039 	int_to_scsilun(scmnd->device->lun, &cmd->lun);
2040 	cmd->tag    = tag;
2041 	memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
2042 
2043 	req->scmnd    = scmnd;
2044 	req->cmd      = iu;
2045 
2046 	len = srp_map_data(scmnd, ch, req);
2047 	if (len < 0) {
2048 		shost_printk(KERN_ERR, target->scsi_host,
2049 			     PFX "Failed to map data (%d)\n", len);
2050 		/*
2051 		 * If we ran out of memory descriptors (-ENOMEM) because an
2052 		 * application is queuing many requests with more than
2053 		 * max_pages_per_mr sg-list elements, tell the SCSI mid-layer
2054 		 * to reduce queue depth temporarily.
2055 		 */
2056 		scmnd->result = len == -ENOMEM ?
2057 			DID_OK << 16 | QUEUE_FULL << 1 : DID_ERROR << 16;
2058 		goto err_iu;
2059 	}
2060 
2061 	ib_dma_sync_single_for_device(dev, iu->dma, target->max_iu_len,
2062 				      DMA_TO_DEVICE);
2063 
2064 	if (srp_post_send(ch, iu, len)) {
2065 		shost_printk(KERN_ERR, target->scsi_host, PFX "Send failed\n");
2066 		goto err_unmap;
2067 	}
2068 
2069 	ret = 0;
2070 
2071 unlock_rport:
2072 	if (in_scsi_eh)
2073 		mutex_unlock(&rport->mutex);
2074 
2075 	return ret;
2076 
2077 err_unmap:
2078 	srp_unmap_data(scmnd, ch, req);
2079 
2080 err_iu:
2081 	srp_put_tx_iu(ch, iu, SRP_IU_CMD);
2082 
2083 	/*
2084 	 * Avoid that the loops that iterate over the request ring can
2085 	 * encounter a dangling SCSI command pointer.
2086 	 */
2087 	req->scmnd = NULL;
2088 
2089 err:
2090 	if (scmnd->result) {
2091 		scmnd->scsi_done(scmnd);
2092 		ret = 0;
2093 	} else {
2094 		ret = SCSI_MLQUEUE_HOST_BUSY;
2095 	}
2096 
2097 	goto unlock_rport;
2098 }
2099 
2100 /*
2101  * Note: the resources allocated in this function are freed in
2102  * srp_free_ch_ib().
2103  */
2104 static int srp_alloc_iu_bufs(struct srp_rdma_ch *ch)
2105 {
2106 	struct srp_target_port *target = ch->target;
2107 	int i;
2108 
2109 	ch->rx_ring = kcalloc(target->queue_size, sizeof(*ch->rx_ring),
2110 			      GFP_KERNEL);
2111 	if (!ch->rx_ring)
2112 		goto err_no_ring;
2113 	ch->tx_ring = kcalloc(target->queue_size, sizeof(*ch->tx_ring),
2114 			      GFP_KERNEL);
2115 	if (!ch->tx_ring)
2116 		goto err_no_ring;
2117 
2118 	for (i = 0; i < target->queue_size; ++i) {
2119 		ch->rx_ring[i] = srp_alloc_iu(target->srp_host,
2120 					      ch->max_ti_iu_len,
2121 					      GFP_KERNEL, DMA_FROM_DEVICE);
2122 		if (!ch->rx_ring[i])
2123 			goto err;
2124 	}
2125 
2126 	for (i = 0; i < target->queue_size; ++i) {
2127 		ch->tx_ring[i] = srp_alloc_iu(target->srp_host,
2128 					      target->max_iu_len,
2129 					      GFP_KERNEL, DMA_TO_DEVICE);
2130 		if (!ch->tx_ring[i])
2131 			goto err;
2132 
2133 		list_add(&ch->tx_ring[i]->list, &ch->free_tx);
2134 	}
2135 
2136 	return 0;
2137 
2138 err:
2139 	for (i = 0; i < target->queue_size; ++i) {
2140 		srp_free_iu(target->srp_host, ch->rx_ring[i]);
2141 		srp_free_iu(target->srp_host, ch->tx_ring[i]);
2142 	}
2143 
2144 
2145 err_no_ring:
2146 	kfree(ch->tx_ring);
2147 	ch->tx_ring = NULL;
2148 	kfree(ch->rx_ring);
2149 	ch->rx_ring = NULL;
2150 
2151 	return -ENOMEM;
2152 }
2153 
2154 static uint32_t srp_compute_rq_tmo(struct ib_qp_attr *qp_attr, int attr_mask)
2155 {
2156 	uint64_t T_tr_ns, max_compl_time_ms;
2157 	uint32_t rq_tmo_jiffies;
2158 
2159 	/*
2160 	 * According to section 11.2.4.2 in the IBTA spec (Modify Queue Pair,
2161 	 * table 91), both the QP timeout and the retry count have to be set
2162 	 * for RC QP's during the RTR to RTS transition.
2163 	 */
2164 	WARN_ON_ONCE((attr_mask & (IB_QP_TIMEOUT | IB_QP_RETRY_CNT)) !=
2165 		     (IB_QP_TIMEOUT | IB_QP_RETRY_CNT));
2166 
2167 	/*
2168 	 * Set target->rq_tmo_jiffies to one second more than the largest time
2169 	 * it can take before an error completion is generated. See also
2170 	 * C9-140..142 in the IBTA spec for more information about how to
2171 	 * convert the QP Local ACK Timeout value to nanoseconds.
2172 	 */
2173 	T_tr_ns = 4096 * (1ULL << qp_attr->timeout);
2174 	max_compl_time_ms = qp_attr->retry_cnt * 4 * T_tr_ns;
2175 	do_div(max_compl_time_ms, NSEC_PER_MSEC);
2176 	rq_tmo_jiffies = msecs_to_jiffies(max_compl_time_ms + 1000);
2177 
2178 	return rq_tmo_jiffies;
2179 }
2180 
2181 static void srp_cm_rep_handler(struct ib_cm_id *cm_id,
2182 			       const struct srp_login_rsp *lrsp,
2183 			       struct srp_rdma_ch *ch)
2184 {
2185 	struct srp_target_port *target = ch->target;
2186 	struct ib_qp_attr *qp_attr = NULL;
2187 	int attr_mask = 0;
2188 	int ret;
2189 	int i;
2190 
2191 	if (lrsp->opcode == SRP_LOGIN_RSP) {
2192 		ch->max_ti_iu_len = be32_to_cpu(lrsp->max_ti_iu_len);
2193 		ch->req_lim       = be32_to_cpu(lrsp->req_lim_delta);
2194 
2195 		/*
2196 		 * Reserve credits for task management so we don't
2197 		 * bounce requests back to the SCSI mid-layer.
2198 		 */
2199 		target->scsi_host->can_queue
2200 			= min(ch->req_lim - SRP_TSK_MGMT_SQ_SIZE,
2201 			      target->scsi_host->can_queue);
2202 		target->scsi_host->cmd_per_lun
2203 			= min_t(int, target->scsi_host->can_queue,
2204 				target->scsi_host->cmd_per_lun);
2205 	} else {
2206 		shost_printk(KERN_WARNING, target->scsi_host,
2207 			     PFX "Unhandled RSP opcode %#x\n", lrsp->opcode);
2208 		ret = -ECONNRESET;
2209 		goto error;
2210 	}
2211 
2212 	if (!ch->rx_ring) {
2213 		ret = srp_alloc_iu_bufs(ch);
2214 		if (ret)
2215 			goto error;
2216 	}
2217 
2218 	ret = -ENOMEM;
2219 	qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
2220 	if (!qp_attr)
2221 		goto error;
2222 
2223 	qp_attr->qp_state = IB_QPS_RTR;
2224 	ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
2225 	if (ret)
2226 		goto error_free;
2227 
2228 	ret = ib_modify_qp(ch->qp, qp_attr, attr_mask);
2229 	if (ret)
2230 		goto error_free;
2231 
2232 	for (i = 0; i < target->queue_size; i++) {
2233 		struct srp_iu *iu = ch->rx_ring[i];
2234 
2235 		ret = srp_post_recv(ch, iu);
2236 		if (ret)
2237 			goto error_free;
2238 	}
2239 
2240 	qp_attr->qp_state = IB_QPS_RTS;
2241 	ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
2242 	if (ret)
2243 		goto error_free;
2244 
2245 	target->rq_tmo_jiffies = srp_compute_rq_tmo(qp_attr, attr_mask);
2246 
2247 	ret = ib_modify_qp(ch->qp, qp_attr, attr_mask);
2248 	if (ret)
2249 		goto error_free;
2250 
2251 	ret = ib_send_cm_rtu(cm_id, NULL, 0);
2252 
2253 error_free:
2254 	kfree(qp_attr);
2255 
2256 error:
2257 	ch->status = ret;
2258 }
2259 
2260 static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
2261 			       struct ib_cm_event *event,
2262 			       struct srp_rdma_ch *ch)
2263 {
2264 	struct srp_target_port *target = ch->target;
2265 	struct Scsi_Host *shost = target->scsi_host;
2266 	struct ib_class_port_info *cpi;
2267 	int opcode;
2268 
2269 	switch (event->param.rej_rcvd.reason) {
2270 	case IB_CM_REJ_PORT_CM_REDIRECT:
2271 		cpi = event->param.rej_rcvd.ari;
2272 		ch->path.dlid = cpi->redirect_lid;
2273 		ch->path.pkey = cpi->redirect_pkey;
2274 		cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
2275 		memcpy(ch->path.dgid.raw, cpi->redirect_gid, 16);
2276 
2277 		ch->status = ch->path.dlid ?
2278 			SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
2279 		break;
2280 
2281 	case IB_CM_REJ_PORT_REDIRECT:
2282 		if (srp_target_is_topspin(target)) {
2283 			/*
2284 			 * Topspin/Cisco SRP gateways incorrectly send
2285 			 * reject reason code 25 when they mean 24
2286 			 * (port redirect).
2287 			 */
2288 			memcpy(ch->path.dgid.raw,
2289 			       event->param.rej_rcvd.ari, 16);
2290 
2291 			shost_printk(KERN_DEBUG, shost,
2292 				     PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
2293 				     be64_to_cpu(ch->path.dgid.global.subnet_prefix),
2294 				     be64_to_cpu(ch->path.dgid.global.interface_id));
2295 
2296 			ch->status = SRP_PORT_REDIRECT;
2297 		} else {
2298 			shost_printk(KERN_WARNING, shost,
2299 				     "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
2300 			ch->status = -ECONNRESET;
2301 		}
2302 		break;
2303 
2304 	case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
2305 		shost_printk(KERN_WARNING, shost,
2306 			    "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
2307 		ch->status = -ECONNRESET;
2308 		break;
2309 
2310 	case IB_CM_REJ_CONSUMER_DEFINED:
2311 		opcode = *(u8 *) event->private_data;
2312 		if (opcode == SRP_LOGIN_REJ) {
2313 			struct srp_login_rej *rej = event->private_data;
2314 			u32 reason = be32_to_cpu(rej->reason);
2315 
2316 			if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
2317 				shost_printk(KERN_WARNING, shost,
2318 					     PFX "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
2319 			else
2320 				shost_printk(KERN_WARNING, shost, PFX
2321 					     "SRP LOGIN from %pI6 to %pI6 REJECTED, reason 0x%08x\n",
2322 					     target->sgid.raw,
2323 					     target->orig_dgid.raw, reason);
2324 		} else
2325 			shost_printk(KERN_WARNING, shost,
2326 				     "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
2327 				     " opcode 0x%02x\n", opcode);
2328 		ch->status = -ECONNRESET;
2329 		break;
2330 
2331 	case IB_CM_REJ_STALE_CONN:
2332 		shost_printk(KERN_WARNING, shost, "  REJ reason: stale connection\n");
2333 		ch->status = SRP_STALE_CONN;
2334 		break;
2335 
2336 	default:
2337 		shost_printk(KERN_WARNING, shost, "  REJ reason 0x%x\n",
2338 			     event->param.rej_rcvd.reason);
2339 		ch->status = -ECONNRESET;
2340 	}
2341 }
2342 
2343 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
2344 {
2345 	struct srp_rdma_ch *ch = cm_id->context;
2346 	struct srp_target_port *target = ch->target;
2347 	int comp = 0;
2348 
2349 	switch (event->event) {
2350 	case IB_CM_REQ_ERROR:
2351 		shost_printk(KERN_DEBUG, target->scsi_host,
2352 			     PFX "Sending CM REQ failed\n");
2353 		comp = 1;
2354 		ch->status = -ECONNRESET;
2355 		break;
2356 
2357 	case IB_CM_REP_RECEIVED:
2358 		comp = 1;
2359 		srp_cm_rep_handler(cm_id, event->private_data, ch);
2360 		break;
2361 
2362 	case IB_CM_REJ_RECEIVED:
2363 		shost_printk(KERN_DEBUG, target->scsi_host, PFX "REJ received\n");
2364 		comp = 1;
2365 
2366 		srp_cm_rej_handler(cm_id, event, ch);
2367 		break;
2368 
2369 	case IB_CM_DREQ_RECEIVED:
2370 		shost_printk(KERN_WARNING, target->scsi_host,
2371 			     PFX "DREQ received - connection closed\n");
2372 		ch->connected = false;
2373 		if (ib_send_cm_drep(cm_id, NULL, 0))
2374 			shost_printk(KERN_ERR, target->scsi_host,
2375 				     PFX "Sending CM DREP failed\n");
2376 		queue_work(system_long_wq, &target->tl_err_work);
2377 		break;
2378 
2379 	case IB_CM_TIMEWAIT_EXIT:
2380 		shost_printk(KERN_ERR, target->scsi_host,
2381 			     PFX "connection closed\n");
2382 		comp = 1;
2383 
2384 		ch->status = 0;
2385 		break;
2386 
2387 	case IB_CM_MRA_RECEIVED:
2388 	case IB_CM_DREQ_ERROR:
2389 	case IB_CM_DREP_RECEIVED:
2390 		break;
2391 
2392 	default:
2393 		shost_printk(KERN_WARNING, target->scsi_host,
2394 			     PFX "Unhandled CM event %d\n", event->event);
2395 		break;
2396 	}
2397 
2398 	if (comp)
2399 		complete(&ch->done);
2400 
2401 	return 0;
2402 }
2403 
2404 /**
2405  * srp_change_queue_depth - setting device queue depth
2406  * @sdev: scsi device struct
2407  * @qdepth: requested queue depth
2408  *
2409  * Returns queue depth.
2410  */
2411 static int
2412 srp_change_queue_depth(struct scsi_device *sdev, int qdepth)
2413 {
2414 	if (!sdev->tagged_supported)
2415 		qdepth = 1;
2416 	return scsi_change_queue_depth(sdev, qdepth);
2417 }
2418 
2419 static int srp_send_tsk_mgmt(struct srp_rdma_ch *ch, u64 req_tag, u64 lun,
2420 			     u8 func)
2421 {
2422 	struct srp_target_port *target = ch->target;
2423 	struct srp_rport *rport = target->rport;
2424 	struct ib_device *dev = target->srp_host->srp_dev->dev;
2425 	struct srp_iu *iu;
2426 	struct srp_tsk_mgmt *tsk_mgmt;
2427 
2428 	if (!ch->connected || target->qp_in_error)
2429 		return -1;
2430 
2431 	init_completion(&ch->tsk_mgmt_done);
2432 
2433 	/*
2434 	 * Lock the rport mutex to avoid that srp_create_ch_ib() is
2435 	 * invoked while a task management function is being sent.
2436 	 */
2437 	mutex_lock(&rport->mutex);
2438 	spin_lock_irq(&ch->lock);
2439 	iu = __srp_get_tx_iu(ch, SRP_IU_TSK_MGMT);
2440 	spin_unlock_irq(&ch->lock);
2441 
2442 	if (!iu) {
2443 		mutex_unlock(&rport->mutex);
2444 
2445 		return -1;
2446 	}
2447 
2448 	ib_dma_sync_single_for_cpu(dev, iu->dma, sizeof *tsk_mgmt,
2449 				   DMA_TO_DEVICE);
2450 	tsk_mgmt = iu->buf;
2451 	memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
2452 
2453 	tsk_mgmt->opcode 	= SRP_TSK_MGMT;
2454 	int_to_scsilun(lun, &tsk_mgmt->lun);
2455 	tsk_mgmt->tag		= req_tag | SRP_TAG_TSK_MGMT;
2456 	tsk_mgmt->tsk_mgmt_func = func;
2457 	tsk_mgmt->task_tag	= req_tag;
2458 
2459 	ib_dma_sync_single_for_device(dev, iu->dma, sizeof *tsk_mgmt,
2460 				      DMA_TO_DEVICE);
2461 	if (srp_post_send(ch, iu, sizeof(*tsk_mgmt))) {
2462 		srp_put_tx_iu(ch, iu, SRP_IU_TSK_MGMT);
2463 		mutex_unlock(&rport->mutex);
2464 
2465 		return -1;
2466 	}
2467 	mutex_unlock(&rport->mutex);
2468 
2469 	if (!wait_for_completion_timeout(&ch->tsk_mgmt_done,
2470 					 msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
2471 		return -1;
2472 
2473 	return 0;
2474 }
2475 
2476 static int srp_abort(struct scsi_cmnd *scmnd)
2477 {
2478 	struct srp_target_port *target = host_to_target(scmnd->device->host);
2479 	struct srp_request *req = (struct srp_request *) scmnd->host_scribble;
2480 	u32 tag;
2481 	u16 ch_idx;
2482 	struct srp_rdma_ch *ch;
2483 	int ret;
2484 
2485 	shost_printk(KERN_ERR, target->scsi_host, "SRP abort called\n");
2486 
2487 	if (!req)
2488 		return SUCCESS;
2489 	tag = blk_mq_unique_tag(scmnd->request);
2490 	ch_idx = blk_mq_unique_tag_to_hwq(tag);
2491 	if (WARN_ON_ONCE(ch_idx >= target->ch_count))
2492 		return SUCCESS;
2493 	ch = &target->ch[ch_idx];
2494 	if (!srp_claim_req(ch, req, NULL, scmnd))
2495 		return SUCCESS;
2496 	shost_printk(KERN_ERR, target->scsi_host,
2497 		     "Sending SRP abort for tag %#x\n", tag);
2498 	if (srp_send_tsk_mgmt(ch, tag, scmnd->device->lun,
2499 			      SRP_TSK_ABORT_TASK) == 0)
2500 		ret = SUCCESS;
2501 	else if (target->rport->state == SRP_RPORT_LOST)
2502 		ret = FAST_IO_FAIL;
2503 	else
2504 		ret = FAILED;
2505 	srp_free_req(ch, req, scmnd, 0);
2506 	scmnd->result = DID_ABORT << 16;
2507 	scmnd->scsi_done(scmnd);
2508 
2509 	return ret;
2510 }
2511 
2512 static int srp_reset_device(struct scsi_cmnd *scmnd)
2513 {
2514 	struct srp_target_port *target = host_to_target(scmnd->device->host);
2515 	struct srp_rdma_ch *ch;
2516 	int i;
2517 
2518 	shost_printk(KERN_ERR, target->scsi_host, "SRP reset_device called\n");
2519 
2520 	ch = &target->ch[0];
2521 	if (srp_send_tsk_mgmt(ch, SRP_TAG_NO_REQ, scmnd->device->lun,
2522 			      SRP_TSK_LUN_RESET))
2523 		return FAILED;
2524 	if (ch->tsk_mgmt_status)
2525 		return FAILED;
2526 
2527 	for (i = 0; i < target->ch_count; i++) {
2528 		ch = &target->ch[i];
2529 		for (i = 0; i < target->req_ring_size; ++i) {
2530 			struct srp_request *req = &ch->req_ring[i];
2531 
2532 			srp_finish_req(ch, req, scmnd->device, DID_RESET << 16);
2533 		}
2534 	}
2535 
2536 	return SUCCESS;
2537 }
2538 
2539 static int srp_reset_host(struct scsi_cmnd *scmnd)
2540 {
2541 	struct srp_target_port *target = host_to_target(scmnd->device->host);
2542 
2543 	shost_printk(KERN_ERR, target->scsi_host, PFX "SRP reset_host called\n");
2544 
2545 	return srp_reconnect_rport(target->rport) == 0 ? SUCCESS : FAILED;
2546 }
2547 
2548 static int srp_slave_configure(struct scsi_device *sdev)
2549 {
2550 	struct Scsi_Host *shost = sdev->host;
2551 	struct srp_target_port *target = host_to_target(shost);
2552 	struct request_queue *q = sdev->request_queue;
2553 	unsigned long timeout;
2554 
2555 	if (sdev->type == TYPE_DISK) {
2556 		timeout = max_t(unsigned, 30 * HZ, target->rq_tmo_jiffies);
2557 		blk_queue_rq_timeout(q, timeout);
2558 	}
2559 
2560 	return 0;
2561 }
2562 
2563 static ssize_t show_id_ext(struct device *dev, struct device_attribute *attr,
2564 			   char *buf)
2565 {
2566 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2567 
2568 	return sprintf(buf, "0x%016llx\n", be64_to_cpu(target->id_ext));
2569 }
2570 
2571 static ssize_t show_ioc_guid(struct device *dev, struct device_attribute *attr,
2572 			     char *buf)
2573 {
2574 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2575 
2576 	return sprintf(buf, "0x%016llx\n", be64_to_cpu(target->ioc_guid));
2577 }
2578 
2579 static ssize_t show_service_id(struct device *dev,
2580 			       struct device_attribute *attr, char *buf)
2581 {
2582 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2583 
2584 	return sprintf(buf, "0x%016llx\n", be64_to_cpu(target->service_id));
2585 }
2586 
2587 static ssize_t show_pkey(struct device *dev, struct device_attribute *attr,
2588 			 char *buf)
2589 {
2590 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2591 
2592 	return sprintf(buf, "0x%04x\n", be16_to_cpu(target->pkey));
2593 }
2594 
2595 static ssize_t show_sgid(struct device *dev, struct device_attribute *attr,
2596 			 char *buf)
2597 {
2598 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2599 
2600 	return sprintf(buf, "%pI6\n", target->sgid.raw);
2601 }
2602 
2603 static ssize_t show_dgid(struct device *dev, struct device_attribute *attr,
2604 			 char *buf)
2605 {
2606 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2607 	struct srp_rdma_ch *ch = &target->ch[0];
2608 
2609 	return sprintf(buf, "%pI6\n", ch->path.dgid.raw);
2610 }
2611 
2612 static ssize_t show_orig_dgid(struct device *dev,
2613 			      struct device_attribute *attr, char *buf)
2614 {
2615 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2616 
2617 	return sprintf(buf, "%pI6\n", target->orig_dgid.raw);
2618 }
2619 
2620 static ssize_t show_req_lim(struct device *dev,
2621 			    struct device_attribute *attr, char *buf)
2622 {
2623 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2624 	struct srp_rdma_ch *ch;
2625 	int i, req_lim = INT_MAX;
2626 
2627 	for (i = 0; i < target->ch_count; i++) {
2628 		ch = &target->ch[i];
2629 		req_lim = min(req_lim, ch->req_lim);
2630 	}
2631 	return sprintf(buf, "%d\n", req_lim);
2632 }
2633 
2634 static ssize_t show_zero_req_lim(struct device *dev,
2635 				 struct device_attribute *attr, char *buf)
2636 {
2637 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2638 
2639 	return sprintf(buf, "%d\n", target->zero_req_lim);
2640 }
2641 
2642 static ssize_t show_local_ib_port(struct device *dev,
2643 				  struct device_attribute *attr, char *buf)
2644 {
2645 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2646 
2647 	return sprintf(buf, "%d\n", target->srp_host->port);
2648 }
2649 
2650 static ssize_t show_local_ib_device(struct device *dev,
2651 				    struct device_attribute *attr, char *buf)
2652 {
2653 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2654 
2655 	return sprintf(buf, "%s\n", target->srp_host->srp_dev->dev->name);
2656 }
2657 
2658 static ssize_t show_ch_count(struct device *dev, struct device_attribute *attr,
2659 			     char *buf)
2660 {
2661 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2662 
2663 	return sprintf(buf, "%d\n", target->ch_count);
2664 }
2665 
2666 static ssize_t show_comp_vector(struct device *dev,
2667 				struct device_attribute *attr, char *buf)
2668 {
2669 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2670 
2671 	return sprintf(buf, "%d\n", target->comp_vector);
2672 }
2673 
2674 static ssize_t show_tl_retry_count(struct device *dev,
2675 				   struct device_attribute *attr, char *buf)
2676 {
2677 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2678 
2679 	return sprintf(buf, "%d\n", target->tl_retry_count);
2680 }
2681 
2682 static ssize_t show_cmd_sg_entries(struct device *dev,
2683 				   struct device_attribute *attr, char *buf)
2684 {
2685 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2686 
2687 	return sprintf(buf, "%u\n", target->cmd_sg_cnt);
2688 }
2689 
2690 static ssize_t show_allow_ext_sg(struct device *dev,
2691 				 struct device_attribute *attr, char *buf)
2692 {
2693 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
2694 
2695 	return sprintf(buf, "%s\n", target->allow_ext_sg ? "true" : "false");
2696 }
2697 
2698 static DEVICE_ATTR(id_ext,	    S_IRUGO, show_id_ext,	   NULL);
2699 static DEVICE_ATTR(ioc_guid,	    S_IRUGO, show_ioc_guid,	   NULL);
2700 static DEVICE_ATTR(service_id,	    S_IRUGO, show_service_id,	   NULL);
2701 static DEVICE_ATTR(pkey,	    S_IRUGO, show_pkey,		   NULL);
2702 static DEVICE_ATTR(sgid,	    S_IRUGO, show_sgid,		   NULL);
2703 static DEVICE_ATTR(dgid,	    S_IRUGO, show_dgid,		   NULL);
2704 static DEVICE_ATTR(orig_dgid,	    S_IRUGO, show_orig_dgid,	   NULL);
2705 static DEVICE_ATTR(req_lim,         S_IRUGO, show_req_lim,         NULL);
2706 static DEVICE_ATTR(zero_req_lim,    S_IRUGO, show_zero_req_lim,	   NULL);
2707 static DEVICE_ATTR(local_ib_port,   S_IRUGO, show_local_ib_port,   NULL);
2708 static DEVICE_ATTR(local_ib_device, S_IRUGO, show_local_ib_device, NULL);
2709 static DEVICE_ATTR(ch_count,        S_IRUGO, show_ch_count,        NULL);
2710 static DEVICE_ATTR(comp_vector,     S_IRUGO, show_comp_vector,     NULL);
2711 static DEVICE_ATTR(tl_retry_count,  S_IRUGO, show_tl_retry_count,  NULL);
2712 static DEVICE_ATTR(cmd_sg_entries,  S_IRUGO, show_cmd_sg_entries,  NULL);
2713 static DEVICE_ATTR(allow_ext_sg,    S_IRUGO, show_allow_ext_sg,    NULL);
2714 
2715 static struct device_attribute *srp_host_attrs[] = {
2716 	&dev_attr_id_ext,
2717 	&dev_attr_ioc_guid,
2718 	&dev_attr_service_id,
2719 	&dev_attr_pkey,
2720 	&dev_attr_sgid,
2721 	&dev_attr_dgid,
2722 	&dev_attr_orig_dgid,
2723 	&dev_attr_req_lim,
2724 	&dev_attr_zero_req_lim,
2725 	&dev_attr_local_ib_port,
2726 	&dev_attr_local_ib_device,
2727 	&dev_attr_ch_count,
2728 	&dev_attr_comp_vector,
2729 	&dev_attr_tl_retry_count,
2730 	&dev_attr_cmd_sg_entries,
2731 	&dev_attr_allow_ext_sg,
2732 	NULL
2733 };
2734 
2735 static struct scsi_host_template srp_template = {
2736 	.module				= THIS_MODULE,
2737 	.name				= "InfiniBand SRP initiator",
2738 	.proc_name			= DRV_NAME,
2739 	.slave_configure		= srp_slave_configure,
2740 	.info				= srp_target_info,
2741 	.queuecommand			= srp_queuecommand,
2742 	.change_queue_depth             = srp_change_queue_depth,
2743 	.eh_abort_handler		= srp_abort,
2744 	.eh_device_reset_handler	= srp_reset_device,
2745 	.eh_host_reset_handler		= srp_reset_host,
2746 	.skip_settle_delay		= true,
2747 	.sg_tablesize			= SRP_DEF_SG_TABLESIZE,
2748 	.can_queue			= SRP_DEFAULT_CMD_SQ_SIZE,
2749 	.this_id			= -1,
2750 	.cmd_per_lun			= SRP_DEFAULT_CMD_SQ_SIZE,
2751 	.use_clustering			= ENABLE_CLUSTERING,
2752 	.shost_attrs			= srp_host_attrs,
2753 	.use_blk_tags			= 1,
2754 	.track_queue_depth		= 1,
2755 };
2756 
2757 static int srp_sdev_count(struct Scsi_Host *host)
2758 {
2759 	struct scsi_device *sdev;
2760 	int c = 0;
2761 
2762 	shost_for_each_device(sdev, host)
2763 		c++;
2764 
2765 	return c;
2766 }
2767 
2768 /*
2769  * Return values:
2770  * < 0 upon failure. Caller is responsible for SRP target port cleanup.
2771  * 0 and target->state == SRP_TARGET_REMOVED if asynchronous target port
2772  *    removal has been scheduled.
2773  * 0 and target->state != SRP_TARGET_REMOVED upon success.
2774  */
2775 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
2776 {
2777 	struct srp_rport_identifiers ids;
2778 	struct srp_rport *rport;
2779 
2780 	target->state = SRP_TARGET_SCANNING;
2781 	sprintf(target->target_name, "SRP.T10:%016llX",
2782 		be64_to_cpu(target->id_ext));
2783 
2784 	if (scsi_add_host(target->scsi_host, host->srp_dev->dev->dma_device))
2785 		return -ENODEV;
2786 
2787 	memcpy(ids.port_id, &target->id_ext, 8);
2788 	memcpy(ids.port_id + 8, &target->ioc_guid, 8);
2789 	ids.roles = SRP_RPORT_ROLE_TARGET;
2790 	rport = srp_rport_add(target->scsi_host, &ids);
2791 	if (IS_ERR(rport)) {
2792 		scsi_remove_host(target->scsi_host);
2793 		return PTR_ERR(rport);
2794 	}
2795 
2796 	rport->lld_data = target;
2797 	target->rport = rport;
2798 
2799 	spin_lock(&host->target_lock);
2800 	list_add_tail(&target->list, &host->target_list);
2801 	spin_unlock(&host->target_lock);
2802 
2803 	scsi_scan_target(&target->scsi_host->shost_gendev,
2804 			 0, target->scsi_id, SCAN_WILD_CARD, 0);
2805 
2806 	if (srp_connected_ch(target) < target->ch_count ||
2807 	    target->qp_in_error) {
2808 		shost_printk(KERN_INFO, target->scsi_host,
2809 			     PFX "SCSI scan failed - removing SCSI host\n");
2810 		srp_queue_remove_work(target);
2811 		goto out;
2812 	}
2813 
2814 	pr_debug(PFX "%s: SCSI scan succeeded - detected %d LUNs\n",
2815 		 dev_name(&target->scsi_host->shost_gendev),
2816 		 srp_sdev_count(target->scsi_host));
2817 
2818 	spin_lock_irq(&target->lock);
2819 	if (target->state == SRP_TARGET_SCANNING)
2820 		target->state = SRP_TARGET_LIVE;
2821 	spin_unlock_irq(&target->lock);
2822 
2823 out:
2824 	return 0;
2825 }
2826 
2827 static void srp_release_dev(struct device *dev)
2828 {
2829 	struct srp_host *host =
2830 		container_of(dev, struct srp_host, dev);
2831 
2832 	complete(&host->released);
2833 }
2834 
2835 static struct class srp_class = {
2836 	.name    = "infiniband_srp",
2837 	.dev_release = srp_release_dev
2838 };
2839 
2840 /**
2841  * srp_conn_unique() - check whether the connection to a target is unique
2842  * @host:   SRP host.
2843  * @target: SRP target port.
2844  */
2845 static bool srp_conn_unique(struct srp_host *host,
2846 			    struct srp_target_port *target)
2847 {
2848 	struct srp_target_port *t;
2849 	bool ret = false;
2850 
2851 	if (target->state == SRP_TARGET_REMOVED)
2852 		goto out;
2853 
2854 	ret = true;
2855 
2856 	spin_lock(&host->target_lock);
2857 	list_for_each_entry(t, &host->target_list, list) {
2858 		if (t != target &&
2859 		    target->id_ext == t->id_ext &&
2860 		    target->ioc_guid == t->ioc_guid &&
2861 		    target->initiator_ext == t->initiator_ext) {
2862 			ret = false;
2863 			break;
2864 		}
2865 	}
2866 	spin_unlock(&host->target_lock);
2867 
2868 out:
2869 	return ret;
2870 }
2871 
2872 /*
2873  * Target ports are added by writing
2874  *
2875  *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
2876  *     pkey=<P_Key>,service_id=<service ID>
2877  *
2878  * to the add_target sysfs attribute.
2879  */
2880 enum {
2881 	SRP_OPT_ERR		= 0,
2882 	SRP_OPT_ID_EXT		= 1 << 0,
2883 	SRP_OPT_IOC_GUID	= 1 << 1,
2884 	SRP_OPT_DGID		= 1 << 2,
2885 	SRP_OPT_PKEY		= 1 << 3,
2886 	SRP_OPT_SERVICE_ID	= 1 << 4,
2887 	SRP_OPT_MAX_SECT	= 1 << 5,
2888 	SRP_OPT_MAX_CMD_PER_LUN	= 1 << 6,
2889 	SRP_OPT_IO_CLASS	= 1 << 7,
2890 	SRP_OPT_INITIATOR_EXT	= 1 << 8,
2891 	SRP_OPT_CMD_SG_ENTRIES	= 1 << 9,
2892 	SRP_OPT_ALLOW_EXT_SG	= 1 << 10,
2893 	SRP_OPT_SG_TABLESIZE	= 1 << 11,
2894 	SRP_OPT_COMP_VECTOR	= 1 << 12,
2895 	SRP_OPT_TL_RETRY_COUNT	= 1 << 13,
2896 	SRP_OPT_QUEUE_SIZE	= 1 << 14,
2897 	SRP_OPT_ALL		= (SRP_OPT_ID_EXT	|
2898 				   SRP_OPT_IOC_GUID	|
2899 				   SRP_OPT_DGID		|
2900 				   SRP_OPT_PKEY		|
2901 				   SRP_OPT_SERVICE_ID),
2902 };
2903 
2904 static const match_table_t srp_opt_tokens = {
2905 	{ SRP_OPT_ID_EXT,		"id_ext=%s" 		},
2906 	{ SRP_OPT_IOC_GUID,		"ioc_guid=%s" 		},
2907 	{ SRP_OPT_DGID,			"dgid=%s" 		},
2908 	{ SRP_OPT_PKEY,			"pkey=%x" 		},
2909 	{ SRP_OPT_SERVICE_ID,		"service_id=%s"		},
2910 	{ SRP_OPT_MAX_SECT,		"max_sect=%d" 		},
2911 	{ SRP_OPT_MAX_CMD_PER_LUN,	"max_cmd_per_lun=%d" 	},
2912 	{ SRP_OPT_IO_CLASS,		"io_class=%x"		},
2913 	{ SRP_OPT_INITIATOR_EXT,	"initiator_ext=%s"	},
2914 	{ SRP_OPT_CMD_SG_ENTRIES,	"cmd_sg_entries=%u"	},
2915 	{ SRP_OPT_ALLOW_EXT_SG,		"allow_ext_sg=%u"	},
2916 	{ SRP_OPT_SG_TABLESIZE,		"sg_tablesize=%u"	},
2917 	{ SRP_OPT_COMP_VECTOR,		"comp_vector=%u"	},
2918 	{ SRP_OPT_TL_RETRY_COUNT,	"tl_retry_count=%u"	},
2919 	{ SRP_OPT_QUEUE_SIZE,		"queue_size=%d"		},
2920 	{ SRP_OPT_ERR,			NULL 			}
2921 };
2922 
2923 static int srp_parse_options(const char *buf, struct srp_target_port *target)
2924 {
2925 	char *options, *sep_opt;
2926 	char *p;
2927 	char dgid[3];
2928 	substring_t args[MAX_OPT_ARGS];
2929 	int opt_mask = 0;
2930 	int token;
2931 	int ret = -EINVAL;
2932 	int i;
2933 
2934 	options = kstrdup(buf, GFP_KERNEL);
2935 	if (!options)
2936 		return -ENOMEM;
2937 
2938 	sep_opt = options;
2939 	while ((p = strsep(&sep_opt, ",\n")) != NULL) {
2940 		if (!*p)
2941 			continue;
2942 
2943 		token = match_token(p, srp_opt_tokens, args);
2944 		opt_mask |= token;
2945 
2946 		switch (token) {
2947 		case SRP_OPT_ID_EXT:
2948 			p = match_strdup(args);
2949 			if (!p) {
2950 				ret = -ENOMEM;
2951 				goto out;
2952 			}
2953 			target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
2954 			kfree(p);
2955 			break;
2956 
2957 		case SRP_OPT_IOC_GUID:
2958 			p = match_strdup(args);
2959 			if (!p) {
2960 				ret = -ENOMEM;
2961 				goto out;
2962 			}
2963 			target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
2964 			kfree(p);
2965 			break;
2966 
2967 		case SRP_OPT_DGID:
2968 			p = match_strdup(args);
2969 			if (!p) {
2970 				ret = -ENOMEM;
2971 				goto out;
2972 			}
2973 			if (strlen(p) != 32) {
2974 				pr_warn("bad dest GID parameter '%s'\n", p);
2975 				kfree(p);
2976 				goto out;
2977 			}
2978 
2979 			for (i = 0; i < 16; ++i) {
2980 				strlcpy(dgid, p + i * 2, sizeof(dgid));
2981 				if (sscanf(dgid, "%hhx",
2982 					   &target->orig_dgid.raw[i]) < 1) {
2983 					ret = -EINVAL;
2984 					kfree(p);
2985 					goto out;
2986 				}
2987 			}
2988 			kfree(p);
2989 			break;
2990 
2991 		case SRP_OPT_PKEY:
2992 			if (match_hex(args, &token)) {
2993 				pr_warn("bad P_Key parameter '%s'\n", p);
2994 				goto out;
2995 			}
2996 			target->pkey = cpu_to_be16(token);
2997 			break;
2998 
2999 		case SRP_OPT_SERVICE_ID:
3000 			p = match_strdup(args);
3001 			if (!p) {
3002 				ret = -ENOMEM;
3003 				goto out;
3004 			}
3005 			target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
3006 			kfree(p);
3007 			break;
3008 
3009 		case SRP_OPT_MAX_SECT:
3010 			if (match_int(args, &token)) {
3011 				pr_warn("bad max sect parameter '%s'\n", p);
3012 				goto out;
3013 			}
3014 			target->scsi_host->max_sectors = token;
3015 			break;
3016 
3017 		case SRP_OPT_QUEUE_SIZE:
3018 			if (match_int(args, &token) || token < 1) {
3019 				pr_warn("bad queue_size parameter '%s'\n", p);
3020 				goto out;
3021 			}
3022 			target->scsi_host->can_queue = token;
3023 			target->queue_size = token + SRP_RSP_SQ_SIZE +
3024 					     SRP_TSK_MGMT_SQ_SIZE;
3025 			if (!(opt_mask & SRP_OPT_MAX_CMD_PER_LUN))
3026 				target->scsi_host->cmd_per_lun = token;
3027 			break;
3028 
3029 		case SRP_OPT_MAX_CMD_PER_LUN:
3030 			if (match_int(args, &token) || token < 1) {
3031 				pr_warn("bad max cmd_per_lun parameter '%s'\n",
3032 					p);
3033 				goto out;
3034 			}
3035 			target->scsi_host->cmd_per_lun = token;
3036 			break;
3037 
3038 		case SRP_OPT_IO_CLASS:
3039 			if (match_hex(args, &token)) {
3040 				pr_warn("bad IO class parameter '%s'\n", p);
3041 				goto out;
3042 			}
3043 			if (token != SRP_REV10_IB_IO_CLASS &&
3044 			    token != SRP_REV16A_IB_IO_CLASS) {
3045 				pr_warn("unknown IO class parameter value %x specified (use %x or %x).\n",
3046 					token, SRP_REV10_IB_IO_CLASS,
3047 					SRP_REV16A_IB_IO_CLASS);
3048 				goto out;
3049 			}
3050 			target->io_class = token;
3051 			break;
3052 
3053 		case SRP_OPT_INITIATOR_EXT:
3054 			p = match_strdup(args);
3055 			if (!p) {
3056 				ret = -ENOMEM;
3057 				goto out;
3058 			}
3059 			target->initiator_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
3060 			kfree(p);
3061 			break;
3062 
3063 		case SRP_OPT_CMD_SG_ENTRIES:
3064 			if (match_int(args, &token) || token < 1 || token > 255) {
3065 				pr_warn("bad max cmd_sg_entries parameter '%s'\n",
3066 					p);
3067 				goto out;
3068 			}
3069 			target->cmd_sg_cnt = token;
3070 			break;
3071 
3072 		case SRP_OPT_ALLOW_EXT_SG:
3073 			if (match_int(args, &token)) {
3074 				pr_warn("bad allow_ext_sg parameter '%s'\n", p);
3075 				goto out;
3076 			}
3077 			target->allow_ext_sg = !!token;
3078 			break;
3079 
3080 		case SRP_OPT_SG_TABLESIZE:
3081 			if (match_int(args, &token) || token < 1 ||
3082 					token > SCSI_MAX_SG_CHAIN_SEGMENTS) {
3083 				pr_warn("bad max sg_tablesize parameter '%s'\n",
3084 					p);
3085 				goto out;
3086 			}
3087 			target->sg_tablesize = token;
3088 			break;
3089 
3090 		case SRP_OPT_COMP_VECTOR:
3091 			if (match_int(args, &token) || token < 0) {
3092 				pr_warn("bad comp_vector parameter '%s'\n", p);
3093 				goto out;
3094 			}
3095 			target->comp_vector = token;
3096 			break;
3097 
3098 		case SRP_OPT_TL_RETRY_COUNT:
3099 			if (match_int(args, &token) || token < 2 || token > 7) {
3100 				pr_warn("bad tl_retry_count parameter '%s' (must be a number between 2 and 7)\n",
3101 					p);
3102 				goto out;
3103 			}
3104 			target->tl_retry_count = token;
3105 			break;
3106 
3107 		default:
3108 			pr_warn("unknown parameter or missing value '%s' in target creation request\n",
3109 				p);
3110 			goto out;
3111 		}
3112 	}
3113 
3114 	if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
3115 		ret = 0;
3116 	else
3117 		for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
3118 			if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
3119 			    !(srp_opt_tokens[i].token & opt_mask))
3120 				pr_warn("target creation request is missing parameter '%s'\n",
3121 					srp_opt_tokens[i].pattern);
3122 
3123 	if (target->scsi_host->cmd_per_lun > target->scsi_host->can_queue
3124 	    && (opt_mask & SRP_OPT_MAX_CMD_PER_LUN))
3125 		pr_warn("cmd_per_lun = %d > queue_size = %d\n",
3126 			target->scsi_host->cmd_per_lun,
3127 			target->scsi_host->can_queue);
3128 
3129 out:
3130 	kfree(options);
3131 	return ret;
3132 }
3133 
3134 static ssize_t srp_create_target(struct device *dev,
3135 				 struct device_attribute *attr,
3136 				 const char *buf, size_t count)
3137 {
3138 	struct srp_host *host =
3139 		container_of(dev, struct srp_host, dev);
3140 	struct Scsi_Host *target_host;
3141 	struct srp_target_port *target;
3142 	struct srp_rdma_ch *ch;
3143 	struct srp_device *srp_dev = host->srp_dev;
3144 	struct ib_device *ibdev = srp_dev->dev;
3145 	int ret, node_idx, node, cpu, i;
3146 	bool multich = false;
3147 
3148 	target_host = scsi_host_alloc(&srp_template,
3149 				      sizeof (struct srp_target_port));
3150 	if (!target_host)
3151 		return -ENOMEM;
3152 
3153 	target_host->transportt  = ib_srp_transport_template;
3154 	target_host->max_channel = 0;
3155 	target_host->max_id      = 1;
3156 	target_host->max_lun     = -1LL;
3157 	target_host->max_cmd_len = sizeof ((struct srp_cmd *) (void *) 0L)->cdb;
3158 
3159 	target = host_to_target(target_host);
3160 
3161 	target->io_class	= SRP_REV16A_IB_IO_CLASS;
3162 	target->scsi_host	= target_host;
3163 	target->srp_host	= host;
3164 	target->lkey		= host->srp_dev->pd->local_dma_lkey;
3165 	target->global_mr	= host->srp_dev->global_mr;
3166 	target->cmd_sg_cnt	= cmd_sg_entries;
3167 	target->sg_tablesize	= indirect_sg_entries ? : cmd_sg_entries;
3168 	target->allow_ext_sg	= allow_ext_sg;
3169 	target->tl_retry_count	= 7;
3170 	target->queue_size	= SRP_DEFAULT_QUEUE_SIZE;
3171 
3172 	/*
3173 	 * Avoid that the SCSI host can be removed by srp_remove_target()
3174 	 * before this function returns.
3175 	 */
3176 	scsi_host_get(target->scsi_host);
3177 
3178 	mutex_lock(&host->add_target_mutex);
3179 
3180 	ret = srp_parse_options(buf, target);
3181 	if (ret)
3182 		goto out;
3183 
3184 	ret = scsi_init_shared_tag_map(target_host, target_host->can_queue);
3185 	if (ret)
3186 		goto out;
3187 
3188 	target->req_ring_size = target->queue_size - SRP_TSK_MGMT_SQ_SIZE;
3189 
3190 	if (!srp_conn_unique(target->srp_host, target)) {
3191 		shost_printk(KERN_INFO, target->scsi_host,
3192 			     PFX "Already connected to target port with id_ext=%016llx;ioc_guid=%016llx;initiator_ext=%016llx\n",
3193 			     be64_to_cpu(target->id_ext),
3194 			     be64_to_cpu(target->ioc_guid),
3195 			     be64_to_cpu(target->initiator_ext));
3196 		ret = -EEXIST;
3197 		goto out;
3198 	}
3199 
3200 	if (!srp_dev->has_fmr && !srp_dev->has_fr && !target->allow_ext_sg &&
3201 	    target->cmd_sg_cnt < target->sg_tablesize) {
3202 		pr_warn("No MR pool and no external indirect descriptors, limiting sg_tablesize to cmd_sg_cnt\n");
3203 		target->sg_tablesize = target->cmd_sg_cnt;
3204 	}
3205 
3206 	target_host->sg_tablesize = target->sg_tablesize;
3207 	target->indirect_size = target->sg_tablesize *
3208 				sizeof (struct srp_direct_buf);
3209 	target->max_iu_len = sizeof (struct srp_cmd) +
3210 			     sizeof (struct srp_indirect_buf) +
3211 			     target->cmd_sg_cnt * sizeof (struct srp_direct_buf);
3212 
3213 	INIT_WORK(&target->tl_err_work, srp_tl_err_work);
3214 	INIT_WORK(&target->remove_work, srp_remove_work);
3215 	spin_lock_init(&target->lock);
3216 	ret = ib_query_gid(ibdev, host->port, 0, &target->sgid);
3217 	if (ret)
3218 		goto out;
3219 
3220 	ret = -ENOMEM;
3221 	target->ch_count = max_t(unsigned, num_online_nodes(),
3222 				 min(ch_count ? :
3223 				     min(4 * num_online_nodes(),
3224 					 ibdev->num_comp_vectors),
3225 				     num_online_cpus()));
3226 	target->ch = kcalloc(target->ch_count, sizeof(*target->ch),
3227 			     GFP_KERNEL);
3228 	if (!target->ch)
3229 		goto out;
3230 
3231 	node_idx = 0;
3232 	for_each_online_node(node) {
3233 		const int ch_start = (node_idx * target->ch_count /
3234 				      num_online_nodes());
3235 		const int ch_end = ((node_idx + 1) * target->ch_count /
3236 				    num_online_nodes());
3237 		const int cv_start = (node_idx * ibdev->num_comp_vectors /
3238 				      num_online_nodes() + target->comp_vector)
3239 				     % ibdev->num_comp_vectors;
3240 		const int cv_end = ((node_idx + 1) * ibdev->num_comp_vectors /
3241 				    num_online_nodes() + target->comp_vector)
3242 				   % ibdev->num_comp_vectors;
3243 		int cpu_idx = 0;
3244 
3245 		for_each_online_cpu(cpu) {
3246 			if (cpu_to_node(cpu) != node)
3247 				continue;
3248 			if (ch_start + cpu_idx >= ch_end)
3249 				continue;
3250 			ch = &target->ch[ch_start + cpu_idx];
3251 			ch->target = target;
3252 			ch->comp_vector = cv_start == cv_end ? cv_start :
3253 				cv_start + cpu_idx % (cv_end - cv_start);
3254 			spin_lock_init(&ch->lock);
3255 			INIT_LIST_HEAD(&ch->free_tx);
3256 			ret = srp_new_cm_id(ch);
3257 			if (ret)
3258 				goto err_disconnect;
3259 
3260 			ret = srp_create_ch_ib(ch);
3261 			if (ret)
3262 				goto err_disconnect;
3263 
3264 			ret = srp_alloc_req_data(ch);
3265 			if (ret)
3266 				goto err_disconnect;
3267 
3268 			ret = srp_connect_ch(ch, multich);
3269 			if (ret) {
3270 				shost_printk(KERN_ERR, target->scsi_host,
3271 					     PFX "Connection %d/%d failed\n",
3272 					     ch_start + cpu_idx,
3273 					     target->ch_count);
3274 				if (node_idx == 0 && cpu_idx == 0) {
3275 					goto err_disconnect;
3276 				} else {
3277 					srp_free_ch_ib(target, ch);
3278 					srp_free_req_data(target, ch);
3279 					target->ch_count = ch - target->ch;
3280 					goto connected;
3281 				}
3282 			}
3283 
3284 			multich = true;
3285 			cpu_idx++;
3286 		}
3287 		node_idx++;
3288 	}
3289 
3290 connected:
3291 	target->scsi_host->nr_hw_queues = target->ch_count;
3292 
3293 	ret = srp_add_target(host, target);
3294 	if (ret)
3295 		goto err_disconnect;
3296 
3297 	if (target->state != SRP_TARGET_REMOVED) {
3298 		shost_printk(KERN_DEBUG, target->scsi_host, PFX
3299 			     "new target: id_ext %016llx ioc_guid %016llx pkey %04x service_id %016llx sgid %pI6 dgid %pI6\n",
3300 			     be64_to_cpu(target->id_ext),
3301 			     be64_to_cpu(target->ioc_guid),
3302 			     be16_to_cpu(target->pkey),
3303 			     be64_to_cpu(target->service_id),
3304 			     target->sgid.raw, target->orig_dgid.raw);
3305 	}
3306 
3307 	ret = count;
3308 
3309 out:
3310 	mutex_unlock(&host->add_target_mutex);
3311 
3312 	scsi_host_put(target->scsi_host);
3313 	if (ret < 0)
3314 		scsi_host_put(target->scsi_host);
3315 
3316 	return ret;
3317 
3318 err_disconnect:
3319 	srp_disconnect_target(target);
3320 
3321 	for (i = 0; i < target->ch_count; i++) {
3322 		ch = &target->ch[i];
3323 		srp_free_ch_ib(target, ch);
3324 		srp_free_req_data(target, ch);
3325 	}
3326 
3327 	kfree(target->ch);
3328 	goto out;
3329 }
3330 
3331 static DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
3332 
3333 static ssize_t show_ibdev(struct device *dev, struct device_attribute *attr,
3334 			  char *buf)
3335 {
3336 	struct srp_host *host = container_of(dev, struct srp_host, dev);
3337 
3338 	return sprintf(buf, "%s\n", host->srp_dev->dev->name);
3339 }
3340 
3341 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
3342 
3343 static ssize_t show_port(struct device *dev, struct device_attribute *attr,
3344 			 char *buf)
3345 {
3346 	struct srp_host *host = container_of(dev, struct srp_host, dev);
3347 
3348 	return sprintf(buf, "%d\n", host->port);
3349 }
3350 
3351 static DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
3352 
3353 static struct srp_host *srp_add_port(struct srp_device *device, u8 port)
3354 {
3355 	struct srp_host *host;
3356 
3357 	host = kzalloc(sizeof *host, GFP_KERNEL);
3358 	if (!host)
3359 		return NULL;
3360 
3361 	INIT_LIST_HEAD(&host->target_list);
3362 	spin_lock_init(&host->target_lock);
3363 	init_completion(&host->released);
3364 	mutex_init(&host->add_target_mutex);
3365 	host->srp_dev = device;
3366 	host->port = port;
3367 
3368 	host->dev.class = &srp_class;
3369 	host->dev.parent = device->dev->dma_device;
3370 	dev_set_name(&host->dev, "srp-%s-%d", device->dev->name, port);
3371 
3372 	if (device_register(&host->dev))
3373 		goto free_host;
3374 	if (device_create_file(&host->dev, &dev_attr_add_target))
3375 		goto err_class;
3376 	if (device_create_file(&host->dev, &dev_attr_ibdev))
3377 		goto err_class;
3378 	if (device_create_file(&host->dev, &dev_attr_port))
3379 		goto err_class;
3380 
3381 	return host;
3382 
3383 err_class:
3384 	device_unregister(&host->dev);
3385 
3386 free_host:
3387 	kfree(host);
3388 
3389 	return NULL;
3390 }
3391 
3392 static void srp_add_one(struct ib_device *device)
3393 {
3394 	struct srp_device *srp_dev;
3395 	struct ib_device_attr *dev_attr;
3396 	struct srp_host *host;
3397 	int mr_page_shift, p;
3398 	u64 max_pages_per_mr;
3399 
3400 	dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
3401 	if (!dev_attr)
3402 		return;
3403 
3404 	if (ib_query_device(device, dev_attr)) {
3405 		pr_warn("Query device failed for %s\n", device->name);
3406 		goto free_attr;
3407 	}
3408 
3409 	srp_dev = kmalloc(sizeof *srp_dev, GFP_KERNEL);
3410 	if (!srp_dev)
3411 		goto free_attr;
3412 
3413 	srp_dev->has_fmr = (device->alloc_fmr && device->dealloc_fmr &&
3414 			    device->map_phys_fmr && device->unmap_fmr);
3415 	srp_dev->has_fr = (dev_attr->device_cap_flags &
3416 			   IB_DEVICE_MEM_MGT_EXTENSIONS);
3417 	if (!srp_dev->has_fmr && !srp_dev->has_fr)
3418 		dev_warn(&device->dev, "neither FMR nor FR is supported\n");
3419 
3420 	srp_dev->use_fast_reg = (srp_dev->has_fr &&
3421 				 (!srp_dev->has_fmr || prefer_fr));
3422 	srp_dev->use_fmr = !srp_dev->use_fast_reg && srp_dev->has_fmr;
3423 
3424 	/*
3425 	 * Use the smallest page size supported by the HCA, down to a
3426 	 * minimum of 4096 bytes. We're unlikely to build large sglists
3427 	 * out of smaller entries.
3428 	 */
3429 	mr_page_shift		= max(12, ffs(dev_attr->page_size_cap) - 1);
3430 	srp_dev->mr_page_size	= 1 << mr_page_shift;
3431 	srp_dev->mr_page_mask	= ~((u64) srp_dev->mr_page_size - 1);
3432 	max_pages_per_mr	= dev_attr->max_mr_size;
3433 	do_div(max_pages_per_mr, srp_dev->mr_page_size);
3434 	srp_dev->max_pages_per_mr = min_t(u64, SRP_MAX_PAGES_PER_MR,
3435 					  max_pages_per_mr);
3436 	if (srp_dev->use_fast_reg) {
3437 		srp_dev->max_pages_per_mr =
3438 			min_t(u32, srp_dev->max_pages_per_mr,
3439 			      dev_attr->max_fast_reg_page_list_len);
3440 	}
3441 	srp_dev->mr_max_size	= srp_dev->mr_page_size *
3442 				   srp_dev->max_pages_per_mr;
3443 	pr_debug("%s: mr_page_shift = %d, dev_attr->max_mr_size = %#llx, dev_attr->max_fast_reg_page_list_len = %u, max_pages_per_mr = %d, mr_max_size = %#x\n",
3444 		 device->name, mr_page_shift, dev_attr->max_mr_size,
3445 		 dev_attr->max_fast_reg_page_list_len,
3446 		 srp_dev->max_pages_per_mr, srp_dev->mr_max_size);
3447 
3448 	INIT_LIST_HEAD(&srp_dev->dev_list);
3449 
3450 	srp_dev->dev = device;
3451 	srp_dev->pd  = ib_alloc_pd(device);
3452 	if (IS_ERR(srp_dev->pd))
3453 		goto free_dev;
3454 
3455 	if (!register_always || (!srp_dev->has_fmr && !srp_dev->has_fr)) {
3456 		srp_dev->global_mr = ib_get_dma_mr(srp_dev->pd,
3457 						   IB_ACCESS_LOCAL_WRITE |
3458 						   IB_ACCESS_REMOTE_READ |
3459 						   IB_ACCESS_REMOTE_WRITE);
3460 		if (IS_ERR(srp_dev->global_mr))
3461 			goto err_pd;
3462 	} else {
3463 		srp_dev->global_mr = NULL;
3464 	}
3465 
3466 	for (p = rdma_start_port(device); p <= rdma_end_port(device); ++p) {
3467 		host = srp_add_port(srp_dev, p);
3468 		if (host)
3469 			list_add_tail(&host->list, &srp_dev->dev_list);
3470 	}
3471 
3472 	ib_set_client_data(device, &srp_client, srp_dev);
3473 
3474 	goto free_attr;
3475 
3476 err_pd:
3477 	ib_dealloc_pd(srp_dev->pd);
3478 
3479 free_dev:
3480 	kfree(srp_dev);
3481 
3482 free_attr:
3483 	kfree(dev_attr);
3484 }
3485 
3486 static void srp_remove_one(struct ib_device *device, void *client_data)
3487 {
3488 	struct srp_device *srp_dev;
3489 	struct srp_host *host, *tmp_host;
3490 	struct srp_target_port *target;
3491 
3492 	srp_dev = client_data;
3493 	if (!srp_dev)
3494 		return;
3495 
3496 	list_for_each_entry_safe(host, tmp_host, &srp_dev->dev_list, list) {
3497 		device_unregister(&host->dev);
3498 		/*
3499 		 * Wait for the sysfs entry to go away, so that no new
3500 		 * target ports can be created.
3501 		 */
3502 		wait_for_completion(&host->released);
3503 
3504 		/*
3505 		 * Remove all target ports.
3506 		 */
3507 		spin_lock(&host->target_lock);
3508 		list_for_each_entry(target, &host->target_list, list)
3509 			srp_queue_remove_work(target);
3510 		spin_unlock(&host->target_lock);
3511 
3512 		/*
3513 		 * Wait for tl_err and target port removal tasks.
3514 		 */
3515 		flush_workqueue(system_long_wq);
3516 		flush_workqueue(srp_remove_wq);
3517 
3518 		kfree(host);
3519 	}
3520 
3521 	if (srp_dev->global_mr)
3522 		ib_dereg_mr(srp_dev->global_mr);
3523 	ib_dealloc_pd(srp_dev->pd);
3524 
3525 	kfree(srp_dev);
3526 }
3527 
3528 static struct srp_function_template ib_srp_transport_functions = {
3529 	.has_rport_state	 = true,
3530 	.reset_timer_if_blocked	 = true,
3531 	.reconnect_delay	 = &srp_reconnect_delay,
3532 	.fast_io_fail_tmo	 = &srp_fast_io_fail_tmo,
3533 	.dev_loss_tmo		 = &srp_dev_loss_tmo,
3534 	.reconnect		 = srp_rport_reconnect,
3535 	.rport_delete		 = srp_rport_delete,
3536 	.terminate_rport_io	 = srp_terminate_io,
3537 };
3538 
3539 static int __init srp_init_module(void)
3540 {
3541 	int ret;
3542 
3543 	BUILD_BUG_ON(FIELD_SIZEOF(struct ib_wc, wr_id) < sizeof(void *));
3544 
3545 	if (srp_sg_tablesize) {
3546 		pr_warn("srp_sg_tablesize is deprecated, please use cmd_sg_entries\n");
3547 		if (!cmd_sg_entries)
3548 			cmd_sg_entries = srp_sg_tablesize;
3549 	}
3550 
3551 	if (!cmd_sg_entries)
3552 		cmd_sg_entries = SRP_DEF_SG_TABLESIZE;
3553 
3554 	if (cmd_sg_entries > 255) {
3555 		pr_warn("Clamping cmd_sg_entries to 255\n");
3556 		cmd_sg_entries = 255;
3557 	}
3558 
3559 	if (!indirect_sg_entries)
3560 		indirect_sg_entries = cmd_sg_entries;
3561 	else if (indirect_sg_entries < cmd_sg_entries) {
3562 		pr_warn("Bumping up indirect_sg_entries to match cmd_sg_entries (%u)\n",
3563 			cmd_sg_entries);
3564 		indirect_sg_entries = cmd_sg_entries;
3565 	}
3566 
3567 	srp_remove_wq = create_workqueue("srp_remove");
3568 	if (!srp_remove_wq) {
3569 		ret = -ENOMEM;
3570 		goto out;
3571 	}
3572 
3573 	ret = -ENOMEM;
3574 	ib_srp_transport_template =
3575 		srp_attach_transport(&ib_srp_transport_functions);
3576 	if (!ib_srp_transport_template)
3577 		goto destroy_wq;
3578 
3579 	ret = class_register(&srp_class);
3580 	if (ret) {
3581 		pr_err("couldn't register class infiniband_srp\n");
3582 		goto release_tr;
3583 	}
3584 
3585 	ib_sa_register_client(&srp_sa_client);
3586 
3587 	ret = ib_register_client(&srp_client);
3588 	if (ret) {
3589 		pr_err("couldn't register IB client\n");
3590 		goto unreg_sa;
3591 	}
3592 
3593 out:
3594 	return ret;
3595 
3596 unreg_sa:
3597 	ib_sa_unregister_client(&srp_sa_client);
3598 	class_unregister(&srp_class);
3599 
3600 release_tr:
3601 	srp_release_transport(ib_srp_transport_template);
3602 
3603 destroy_wq:
3604 	destroy_workqueue(srp_remove_wq);
3605 	goto out;
3606 }
3607 
3608 static void __exit srp_cleanup_module(void)
3609 {
3610 	ib_unregister_client(&srp_client);
3611 	ib_sa_unregister_client(&srp_sa_client);
3612 	class_unregister(&srp_class);
3613 	srp_release_transport(ib_srp_transport_template);
3614 	destroy_workqueue(srp_remove_wq);
3615 }
3616 
3617 module_init(srp_init_module);
3618 module_exit(srp_cleanup_module);
3619