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 #include <linux/module.h>
34 #include <linux/init.h>
35 #include <linux/slab.h>
36 #include <linux/err.h>
37 #include <linux/string.h>
38 #include <linux/parser.h>
39 #include <linux/random.h>
40 #include <linux/jiffies.h>
41 
42 #include <linux/atomic.h>
43 
44 #include <scsi/scsi.h>
45 #include <scsi/scsi_device.h>
46 #include <scsi/scsi_dbg.h>
47 #include <scsi/srp.h>
48 #include <scsi/scsi_transport_srp.h>
49 
50 #include "ib_srp.h"
51 
52 #define DRV_NAME	"ib_srp"
53 #define PFX		DRV_NAME ": "
54 #define DRV_VERSION	"0.2"
55 #define DRV_RELDATE	"November 1, 2005"
56 
57 MODULE_AUTHOR("Roland Dreier");
58 MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol initiator "
59 		   "v" DRV_VERSION " (" DRV_RELDATE ")");
60 MODULE_LICENSE("Dual BSD/GPL");
61 
62 static unsigned int srp_sg_tablesize;
63 static unsigned int cmd_sg_entries;
64 static unsigned int indirect_sg_entries;
65 static bool allow_ext_sg;
66 static int topspin_workarounds = 1;
67 
68 module_param(srp_sg_tablesize, uint, 0444);
69 MODULE_PARM_DESC(srp_sg_tablesize, "Deprecated name for cmd_sg_entries");
70 
71 module_param(cmd_sg_entries, uint, 0444);
72 MODULE_PARM_DESC(cmd_sg_entries,
73 		 "Default number of gather/scatter entries in the SRP command (default is 12, max 255)");
74 
75 module_param(indirect_sg_entries, uint, 0444);
76 MODULE_PARM_DESC(indirect_sg_entries,
77 		 "Default max number of gather/scatter entries (default is 12, max is " __stringify(SCSI_MAX_SG_CHAIN_SEGMENTS) ")");
78 
79 module_param(allow_ext_sg, bool, 0444);
80 MODULE_PARM_DESC(allow_ext_sg,
81 		  "Default behavior when there are more than cmd_sg_entries S/G entries after mapping; fails the request when false (default false)");
82 
83 module_param(topspin_workarounds, int, 0444);
84 MODULE_PARM_DESC(topspin_workarounds,
85 		 "Enable workarounds for Topspin/Cisco SRP target bugs if != 0");
86 
87 static void srp_add_one(struct ib_device *device);
88 static void srp_remove_one(struct ib_device *device);
89 static void srp_recv_completion(struct ib_cq *cq, void *target_ptr);
90 static void srp_send_completion(struct ib_cq *cq, void *target_ptr);
91 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);
92 
93 static struct scsi_transport_template *ib_srp_transport_template;
94 
95 static struct ib_client srp_client = {
96 	.name   = "srp",
97 	.add    = srp_add_one,
98 	.remove = srp_remove_one
99 };
100 
101 static struct ib_sa_client srp_sa_client;
102 
103 static inline struct srp_target_port *host_to_target(struct Scsi_Host *host)
104 {
105 	return (struct srp_target_port *) host->hostdata;
106 }
107 
108 static const char *srp_target_info(struct Scsi_Host *host)
109 {
110 	return host_to_target(host)->target_name;
111 }
112 
113 static int srp_target_is_topspin(struct srp_target_port *target)
114 {
115 	static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
116 	static const u8 cisco_oui[3]   = { 0x00, 0x1b, 0x0d };
117 
118 	return topspin_workarounds &&
119 		(!memcmp(&target->ioc_guid, topspin_oui, sizeof topspin_oui) ||
120 		 !memcmp(&target->ioc_guid, cisco_oui, sizeof cisco_oui));
121 }
122 
123 static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
124 				   gfp_t gfp_mask,
125 				   enum dma_data_direction direction)
126 {
127 	struct srp_iu *iu;
128 
129 	iu = kmalloc(sizeof *iu, gfp_mask);
130 	if (!iu)
131 		goto out;
132 
133 	iu->buf = kzalloc(size, gfp_mask);
134 	if (!iu->buf)
135 		goto out_free_iu;
136 
137 	iu->dma = ib_dma_map_single(host->srp_dev->dev, iu->buf, size,
138 				    direction);
139 	if (ib_dma_mapping_error(host->srp_dev->dev, iu->dma))
140 		goto out_free_buf;
141 
142 	iu->size      = size;
143 	iu->direction = direction;
144 
145 	return iu;
146 
147 out_free_buf:
148 	kfree(iu->buf);
149 out_free_iu:
150 	kfree(iu);
151 out:
152 	return NULL;
153 }
154 
155 static void srp_free_iu(struct srp_host *host, struct srp_iu *iu)
156 {
157 	if (!iu)
158 		return;
159 
160 	ib_dma_unmap_single(host->srp_dev->dev, iu->dma, iu->size,
161 			    iu->direction);
162 	kfree(iu->buf);
163 	kfree(iu);
164 }
165 
166 static void srp_qp_event(struct ib_event *event, void *context)
167 {
168 	printk(KERN_ERR PFX "QP event %d\n", event->event);
169 }
170 
171 static int srp_init_qp(struct srp_target_port *target,
172 		       struct ib_qp *qp)
173 {
174 	struct ib_qp_attr *attr;
175 	int ret;
176 
177 	attr = kmalloc(sizeof *attr, GFP_KERNEL);
178 	if (!attr)
179 		return -ENOMEM;
180 
181 	ret = ib_find_pkey(target->srp_host->srp_dev->dev,
182 			   target->srp_host->port,
183 			   be16_to_cpu(target->path.pkey),
184 			   &attr->pkey_index);
185 	if (ret)
186 		goto out;
187 
188 	attr->qp_state        = IB_QPS_INIT;
189 	attr->qp_access_flags = (IB_ACCESS_REMOTE_READ |
190 				    IB_ACCESS_REMOTE_WRITE);
191 	attr->port_num        = target->srp_host->port;
192 
193 	ret = ib_modify_qp(qp, attr,
194 			   IB_QP_STATE		|
195 			   IB_QP_PKEY_INDEX	|
196 			   IB_QP_ACCESS_FLAGS	|
197 			   IB_QP_PORT);
198 
199 out:
200 	kfree(attr);
201 	return ret;
202 }
203 
204 static int srp_new_cm_id(struct srp_target_port *target)
205 {
206 	struct ib_cm_id *new_cm_id;
207 
208 	new_cm_id = ib_create_cm_id(target->srp_host->srp_dev->dev,
209 				    srp_cm_handler, target);
210 	if (IS_ERR(new_cm_id))
211 		return PTR_ERR(new_cm_id);
212 
213 	if (target->cm_id)
214 		ib_destroy_cm_id(target->cm_id);
215 	target->cm_id = new_cm_id;
216 
217 	return 0;
218 }
219 
220 static int srp_create_target_ib(struct srp_target_port *target)
221 {
222 	struct ib_qp_init_attr *init_attr;
223 	int ret;
224 
225 	init_attr = kzalloc(sizeof *init_attr, GFP_KERNEL);
226 	if (!init_attr)
227 		return -ENOMEM;
228 
229 	target->recv_cq = ib_create_cq(target->srp_host->srp_dev->dev,
230 				       srp_recv_completion, NULL, target, SRP_RQ_SIZE, 0);
231 	if (IS_ERR(target->recv_cq)) {
232 		ret = PTR_ERR(target->recv_cq);
233 		goto err;
234 	}
235 
236 	target->send_cq = ib_create_cq(target->srp_host->srp_dev->dev,
237 				       srp_send_completion, NULL, target, SRP_SQ_SIZE, 0);
238 	if (IS_ERR(target->send_cq)) {
239 		ret = PTR_ERR(target->send_cq);
240 		goto err_recv_cq;
241 	}
242 
243 	ib_req_notify_cq(target->recv_cq, IB_CQ_NEXT_COMP);
244 
245 	init_attr->event_handler       = srp_qp_event;
246 	init_attr->cap.max_send_wr     = SRP_SQ_SIZE;
247 	init_attr->cap.max_recv_wr     = SRP_RQ_SIZE;
248 	init_attr->cap.max_recv_sge    = 1;
249 	init_attr->cap.max_send_sge    = 1;
250 	init_attr->sq_sig_type         = IB_SIGNAL_ALL_WR;
251 	init_attr->qp_type             = IB_QPT_RC;
252 	init_attr->send_cq             = target->send_cq;
253 	init_attr->recv_cq             = target->recv_cq;
254 
255 	target->qp = ib_create_qp(target->srp_host->srp_dev->pd, init_attr);
256 	if (IS_ERR(target->qp)) {
257 		ret = PTR_ERR(target->qp);
258 		goto err_send_cq;
259 	}
260 
261 	ret = srp_init_qp(target, target->qp);
262 	if (ret)
263 		goto err_qp;
264 
265 	kfree(init_attr);
266 	return 0;
267 
268 err_qp:
269 	ib_destroy_qp(target->qp);
270 
271 err_send_cq:
272 	ib_destroy_cq(target->send_cq);
273 
274 err_recv_cq:
275 	ib_destroy_cq(target->recv_cq);
276 
277 err:
278 	kfree(init_attr);
279 	return ret;
280 }
281 
282 static void srp_free_target_ib(struct srp_target_port *target)
283 {
284 	int i;
285 
286 	ib_destroy_qp(target->qp);
287 	ib_destroy_cq(target->send_cq);
288 	ib_destroy_cq(target->recv_cq);
289 
290 	for (i = 0; i < SRP_RQ_SIZE; ++i)
291 		srp_free_iu(target->srp_host, target->rx_ring[i]);
292 	for (i = 0; i < SRP_SQ_SIZE; ++i)
293 		srp_free_iu(target->srp_host, target->tx_ring[i]);
294 }
295 
296 static void srp_path_rec_completion(int status,
297 				    struct ib_sa_path_rec *pathrec,
298 				    void *target_ptr)
299 {
300 	struct srp_target_port *target = target_ptr;
301 
302 	target->status = status;
303 	if (status)
304 		shost_printk(KERN_ERR, target->scsi_host,
305 			     PFX "Got failed path rec status %d\n", status);
306 	else
307 		target->path = *pathrec;
308 	complete(&target->done);
309 }
310 
311 static int srp_lookup_path(struct srp_target_port *target)
312 {
313 	target->path.numb_path = 1;
314 
315 	init_completion(&target->done);
316 
317 	target->path_query_id = ib_sa_path_rec_get(&srp_sa_client,
318 						   target->srp_host->srp_dev->dev,
319 						   target->srp_host->port,
320 						   &target->path,
321 						   IB_SA_PATH_REC_SERVICE_ID	|
322 						   IB_SA_PATH_REC_DGID		|
323 						   IB_SA_PATH_REC_SGID		|
324 						   IB_SA_PATH_REC_NUMB_PATH	|
325 						   IB_SA_PATH_REC_PKEY,
326 						   SRP_PATH_REC_TIMEOUT_MS,
327 						   GFP_KERNEL,
328 						   srp_path_rec_completion,
329 						   target, &target->path_query);
330 	if (target->path_query_id < 0)
331 		return target->path_query_id;
332 
333 	wait_for_completion(&target->done);
334 
335 	if (target->status < 0)
336 		shost_printk(KERN_WARNING, target->scsi_host,
337 			     PFX "Path record query failed\n");
338 
339 	return target->status;
340 }
341 
342 static int srp_send_req(struct srp_target_port *target)
343 {
344 	struct {
345 		struct ib_cm_req_param param;
346 		struct srp_login_req   priv;
347 	} *req = NULL;
348 	int status;
349 
350 	req = kzalloc(sizeof *req, GFP_KERNEL);
351 	if (!req)
352 		return -ENOMEM;
353 
354 	req->param.primary_path 	      = &target->path;
355 	req->param.alternate_path 	      = NULL;
356 	req->param.service_id 		      = target->service_id;
357 	req->param.qp_num 		      = target->qp->qp_num;
358 	req->param.qp_type 		      = target->qp->qp_type;
359 	req->param.private_data 	      = &req->priv;
360 	req->param.private_data_len 	      = sizeof req->priv;
361 	req->param.flow_control 	      = 1;
362 
363 	get_random_bytes(&req->param.starting_psn, 4);
364 	req->param.starting_psn 	     &= 0xffffff;
365 
366 	/*
367 	 * Pick some arbitrary defaults here; we could make these
368 	 * module parameters if anyone cared about setting them.
369 	 */
370 	req->param.responder_resources	      = 4;
371 	req->param.remote_cm_response_timeout = 20;
372 	req->param.local_cm_response_timeout  = 20;
373 	req->param.retry_count 		      = 7;
374 	req->param.rnr_retry_count 	      = 7;
375 	req->param.max_cm_retries 	      = 15;
376 
377 	req->priv.opcode     	= SRP_LOGIN_REQ;
378 	req->priv.tag        	= 0;
379 	req->priv.req_it_iu_len = cpu_to_be32(target->max_iu_len);
380 	req->priv.req_buf_fmt 	= cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
381 					      SRP_BUF_FORMAT_INDIRECT);
382 	/*
383 	 * In the published SRP specification (draft rev. 16a), the
384 	 * port identifier format is 8 bytes of ID extension followed
385 	 * by 8 bytes of GUID.  Older drafts put the two halves in the
386 	 * opposite order, so that the GUID comes first.
387 	 *
388 	 * Targets conforming to these obsolete drafts can be
389 	 * recognized by the I/O Class they report.
390 	 */
391 	if (target->io_class == SRP_REV10_IB_IO_CLASS) {
392 		memcpy(req->priv.initiator_port_id,
393 		       &target->path.sgid.global.interface_id, 8);
394 		memcpy(req->priv.initiator_port_id + 8,
395 		       &target->initiator_ext, 8);
396 		memcpy(req->priv.target_port_id,     &target->ioc_guid, 8);
397 		memcpy(req->priv.target_port_id + 8, &target->id_ext, 8);
398 	} else {
399 		memcpy(req->priv.initiator_port_id,
400 		       &target->initiator_ext, 8);
401 		memcpy(req->priv.initiator_port_id + 8,
402 		       &target->path.sgid.global.interface_id, 8);
403 		memcpy(req->priv.target_port_id,     &target->id_ext, 8);
404 		memcpy(req->priv.target_port_id + 8, &target->ioc_guid, 8);
405 	}
406 
407 	/*
408 	 * Topspin/Cisco SRP targets will reject our login unless we
409 	 * zero out the first 8 bytes of our initiator port ID and set
410 	 * the second 8 bytes to the local node GUID.
411 	 */
412 	if (srp_target_is_topspin(target)) {
413 		shost_printk(KERN_DEBUG, target->scsi_host,
414 			     PFX "Topspin/Cisco initiator port ID workaround "
415 			     "activated for target GUID %016llx\n",
416 			     (unsigned long long) be64_to_cpu(target->ioc_guid));
417 		memset(req->priv.initiator_port_id, 0, 8);
418 		memcpy(req->priv.initiator_port_id + 8,
419 		       &target->srp_host->srp_dev->dev->node_guid, 8);
420 	}
421 
422 	status = ib_send_cm_req(target->cm_id, &req->param);
423 
424 	kfree(req);
425 
426 	return status;
427 }
428 
429 static void srp_disconnect_target(struct srp_target_port *target)
430 {
431 	/* XXX should send SRP_I_LOGOUT request */
432 
433 	init_completion(&target->done);
434 	if (ib_send_cm_dreq(target->cm_id, NULL, 0)) {
435 		shost_printk(KERN_DEBUG, target->scsi_host,
436 			     PFX "Sending CM DREQ failed\n");
437 		return;
438 	}
439 	wait_for_completion(&target->done);
440 }
441 
442 static bool srp_change_state(struct srp_target_port *target,
443 			    enum srp_target_state old,
444 			    enum srp_target_state new)
445 {
446 	bool changed = false;
447 
448 	spin_lock_irq(&target->lock);
449 	if (target->state == old) {
450 		target->state = new;
451 		changed = true;
452 	}
453 	spin_unlock_irq(&target->lock);
454 	return changed;
455 }
456 
457 static void srp_free_req_data(struct srp_target_port *target)
458 {
459 	struct ib_device *ibdev = target->srp_host->srp_dev->dev;
460 	struct srp_request *req;
461 	int i;
462 
463 	for (i = 0, req = target->req_ring; i < SRP_CMD_SQ_SIZE; ++i, ++req) {
464 		kfree(req->fmr_list);
465 		kfree(req->map_page);
466 		if (req->indirect_dma_addr) {
467 			ib_dma_unmap_single(ibdev, req->indirect_dma_addr,
468 					    target->indirect_size,
469 					    DMA_TO_DEVICE);
470 		}
471 		kfree(req->indirect_desc);
472 	}
473 }
474 
475 static void srp_remove_work(struct work_struct *work)
476 {
477 	struct srp_target_port *target =
478 		container_of(work, struct srp_target_port, work);
479 
480 	if (!srp_change_state(target, SRP_TARGET_DEAD, SRP_TARGET_REMOVED))
481 		return;
482 
483 	spin_lock(&target->srp_host->target_lock);
484 	list_del(&target->list);
485 	spin_unlock(&target->srp_host->target_lock);
486 
487 	srp_remove_host(target->scsi_host);
488 	scsi_remove_host(target->scsi_host);
489 	ib_destroy_cm_id(target->cm_id);
490 	srp_free_target_ib(target);
491 	srp_free_req_data(target);
492 	scsi_host_put(target->scsi_host);
493 }
494 
495 static int srp_connect_target(struct srp_target_port *target)
496 {
497 	int retries = 3;
498 	int ret;
499 
500 	ret = srp_lookup_path(target);
501 	if (ret)
502 		return ret;
503 
504 	while (1) {
505 		init_completion(&target->done);
506 		ret = srp_send_req(target);
507 		if (ret)
508 			return ret;
509 		wait_for_completion(&target->done);
510 
511 		/*
512 		 * The CM event handling code will set status to
513 		 * SRP_PORT_REDIRECT if we get a port redirect REJ
514 		 * back, or SRP_DLID_REDIRECT if we get a lid/qp
515 		 * redirect REJ back.
516 		 */
517 		switch (target->status) {
518 		case 0:
519 			return 0;
520 
521 		case SRP_PORT_REDIRECT:
522 			ret = srp_lookup_path(target);
523 			if (ret)
524 				return ret;
525 			break;
526 
527 		case SRP_DLID_REDIRECT:
528 			break;
529 
530 		case SRP_STALE_CONN:
531 			/* Our current CM id was stale, and is now in timewait.
532 			 * Try to reconnect with a new one.
533 			 */
534 			if (!retries-- || srp_new_cm_id(target)) {
535 				shost_printk(KERN_ERR, target->scsi_host, PFX
536 					     "giving up on stale connection\n");
537 				target->status = -ECONNRESET;
538 				return target->status;
539 			}
540 
541 			shost_printk(KERN_ERR, target->scsi_host, PFX
542 				     "retrying stale connection\n");
543 			break;
544 
545 		default:
546 			return target->status;
547 		}
548 	}
549 }
550 
551 static void srp_unmap_data(struct scsi_cmnd *scmnd,
552 			   struct srp_target_port *target,
553 			   struct srp_request *req)
554 {
555 	struct ib_device *ibdev = target->srp_host->srp_dev->dev;
556 	struct ib_pool_fmr **pfmr;
557 
558 	if (!scsi_sglist(scmnd) ||
559 	    (scmnd->sc_data_direction != DMA_TO_DEVICE &&
560 	     scmnd->sc_data_direction != DMA_FROM_DEVICE))
561 		return;
562 
563 	pfmr = req->fmr_list;
564 	while (req->nfmr--)
565 		ib_fmr_pool_unmap(*pfmr++);
566 
567 	ib_dma_unmap_sg(ibdev, scsi_sglist(scmnd), scsi_sg_count(scmnd),
568 			scmnd->sc_data_direction);
569 }
570 
571 static void srp_remove_req(struct srp_target_port *target,
572 			   struct srp_request *req, s32 req_lim_delta)
573 {
574 	unsigned long flags;
575 
576 	srp_unmap_data(req->scmnd, target, req);
577 	spin_lock_irqsave(&target->lock, flags);
578 	target->req_lim += req_lim_delta;
579 	req->scmnd = NULL;
580 	list_add_tail(&req->list, &target->free_reqs);
581 	spin_unlock_irqrestore(&target->lock, flags);
582 }
583 
584 static void srp_reset_req(struct srp_target_port *target, struct srp_request *req)
585 {
586 	req->scmnd->result = DID_RESET << 16;
587 	req->scmnd->scsi_done(req->scmnd);
588 	srp_remove_req(target, req, 0);
589 }
590 
591 static int srp_reconnect_target(struct srp_target_port *target)
592 {
593 	struct ib_qp_attr qp_attr;
594 	struct ib_wc wc;
595 	int i, ret;
596 
597 	if (!srp_change_state(target, SRP_TARGET_LIVE, SRP_TARGET_CONNECTING))
598 		return -EAGAIN;
599 
600 	srp_disconnect_target(target);
601 	/*
602 	 * Now get a new local CM ID so that we avoid confusing the
603 	 * target in case things are really fouled up.
604 	 */
605 	ret = srp_new_cm_id(target);
606 	if (ret)
607 		goto err;
608 
609 	qp_attr.qp_state = IB_QPS_RESET;
610 	ret = ib_modify_qp(target->qp, &qp_attr, IB_QP_STATE);
611 	if (ret)
612 		goto err;
613 
614 	ret = srp_init_qp(target, target->qp);
615 	if (ret)
616 		goto err;
617 
618 	while (ib_poll_cq(target->recv_cq, 1, &wc) > 0)
619 		; /* nothing */
620 	while (ib_poll_cq(target->send_cq, 1, &wc) > 0)
621 		; /* nothing */
622 
623 	for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
624 		struct srp_request *req = &target->req_ring[i];
625 		if (req->scmnd)
626 			srp_reset_req(target, req);
627 	}
628 
629 	INIT_LIST_HEAD(&target->free_tx);
630 	for (i = 0; i < SRP_SQ_SIZE; ++i)
631 		list_add(&target->tx_ring[i]->list, &target->free_tx);
632 
633 	target->qp_in_error = 0;
634 	ret = srp_connect_target(target);
635 	if (ret)
636 		goto err;
637 
638 	if (!srp_change_state(target, SRP_TARGET_CONNECTING, SRP_TARGET_LIVE))
639 		ret = -EAGAIN;
640 
641 	return ret;
642 
643 err:
644 	shost_printk(KERN_ERR, target->scsi_host,
645 		     PFX "reconnect failed (%d), removing target port.\n", ret);
646 
647 	/*
648 	 * We couldn't reconnect, so kill our target port off.
649 	 * However, we have to defer the real removal because we
650 	 * are in the context of the SCSI error handler now, which
651 	 * will deadlock if we call scsi_remove_host().
652 	 *
653 	 * Schedule our work inside the lock to avoid a race with
654 	 * the flush_scheduled_work() in srp_remove_one().
655 	 */
656 	spin_lock_irq(&target->lock);
657 	if (target->state == SRP_TARGET_CONNECTING) {
658 		target->state = SRP_TARGET_DEAD;
659 		INIT_WORK(&target->work, srp_remove_work);
660 		queue_work(ib_wq, &target->work);
661 	}
662 	spin_unlock_irq(&target->lock);
663 
664 	return ret;
665 }
666 
667 static void srp_map_desc(struct srp_map_state *state, dma_addr_t dma_addr,
668 			 unsigned int dma_len, u32 rkey)
669 {
670 	struct srp_direct_buf *desc = state->desc;
671 
672 	desc->va = cpu_to_be64(dma_addr);
673 	desc->key = cpu_to_be32(rkey);
674 	desc->len = cpu_to_be32(dma_len);
675 
676 	state->total_len += dma_len;
677 	state->desc++;
678 	state->ndesc++;
679 }
680 
681 static int srp_map_finish_fmr(struct srp_map_state *state,
682 			      struct srp_target_port *target)
683 {
684 	struct srp_device *dev = target->srp_host->srp_dev;
685 	struct ib_pool_fmr *fmr;
686 	u64 io_addr = 0;
687 
688 	if (!state->npages)
689 		return 0;
690 
691 	if (state->npages == 1) {
692 		srp_map_desc(state, state->base_dma_addr, state->fmr_len,
693 			     target->rkey);
694 		state->npages = state->fmr_len = 0;
695 		return 0;
696 	}
697 
698 	fmr = ib_fmr_pool_map_phys(dev->fmr_pool, state->pages,
699 				   state->npages, io_addr);
700 	if (IS_ERR(fmr))
701 		return PTR_ERR(fmr);
702 
703 	*state->next_fmr++ = fmr;
704 	state->nfmr++;
705 
706 	srp_map_desc(state, 0, state->fmr_len, fmr->fmr->rkey);
707 	state->npages = state->fmr_len = 0;
708 	return 0;
709 }
710 
711 static void srp_map_update_start(struct srp_map_state *state,
712 				 struct scatterlist *sg, int sg_index,
713 				 dma_addr_t dma_addr)
714 {
715 	state->unmapped_sg = sg;
716 	state->unmapped_index = sg_index;
717 	state->unmapped_addr = dma_addr;
718 }
719 
720 static int srp_map_sg_entry(struct srp_map_state *state,
721 			    struct srp_target_port *target,
722 			    struct scatterlist *sg, int sg_index,
723 			    int use_fmr)
724 {
725 	struct srp_device *dev = target->srp_host->srp_dev;
726 	struct ib_device *ibdev = dev->dev;
727 	dma_addr_t dma_addr = ib_sg_dma_address(ibdev, sg);
728 	unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
729 	unsigned int len;
730 	int ret;
731 
732 	if (!dma_len)
733 		return 0;
734 
735 	if (use_fmr == SRP_MAP_NO_FMR) {
736 		/* Once we're in direct map mode for a request, we don't
737 		 * go back to FMR mode, so no need to update anything
738 		 * other than the descriptor.
739 		 */
740 		srp_map_desc(state, dma_addr, dma_len, target->rkey);
741 		return 0;
742 	}
743 
744 	/* If we start at an offset into the FMR page, don't merge into
745 	 * the current FMR. Finish it out, and use the kernel's MR for this
746 	 * sg entry. This is to avoid potential bugs on some SRP targets
747 	 * that were never quite defined, but went away when the initiator
748 	 * avoided using FMR on such page fragments.
749 	 */
750 	if (dma_addr & ~dev->fmr_page_mask || dma_len > dev->fmr_max_size) {
751 		ret = srp_map_finish_fmr(state, target);
752 		if (ret)
753 			return ret;
754 
755 		srp_map_desc(state, dma_addr, dma_len, target->rkey);
756 		srp_map_update_start(state, NULL, 0, 0);
757 		return 0;
758 	}
759 
760 	/* If this is the first sg to go into the FMR, save our position.
761 	 * We need to know the first unmapped entry, its index, and the
762 	 * first unmapped address within that entry to be able to restart
763 	 * mapping after an error.
764 	 */
765 	if (!state->unmapped_sg)
766 		srp_map_update_start(state, sg, sg_index, dma_addr);
767 
768 	while (dma_len) {
769 		if (state->npages == SRP_FMR_SIZE) {
770 			ret = srp_map_finish_fmr(state, target);
771 			if (ret)
772 				return ret;
773 
774 			srp_map_update_start(state, sg, sg_index, dma_addr);
775 		}
776 
777 		len = min_t(unsigned int, dma_len, dev->fmr_page_size);
778 
779 		if (!state->npages)
780 			state->base_dma_addr = dma_addr;
781 		state->pages[state->npages++] = dma_addr;
782 		state->fmr_len += len;
783 		dma_addr += len;
784 		dma_len -= len;
785 	}
786 
787 	/* If the last entry of the FMR wasn't a full page, then we need to
788 	 * close it out and start a new one -- we can only merge at page
789 	 * boundries.
790 	 */
791 	ret = 0;
792 	if (len != dev->fmr_page_size) {
793 		ret = srp_map_finish_fmr(state, target);
794 		if (!ret)
795 			srp_map_update_start(state, NULL, 0, 0);
796 	}
797 	return ret;
798 }
799 
800 static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
801 			struct srp_request *req)
802 {
803 	struct scatterlist *scat, *sg;
804 	struct srp_cmd *cmd = req->cmd->buf;
805 	int i, len, nents, count, use_fmr;
806 	struct srp_device *dev;
807 	struct ib_device *ibdev;
808 	struct srp_map_state state;
809 	struct srp_indirect_buf *indirect_hdr;
810 	u32 table_len;
811 	u8 fmt;
812 
813 	if (!scsi_sglist(scmnd) || scmnd->sc_data_direction == DMA_NONE)
814 		return sizeof (struct srp_cmd);
815 
816 	if (scmnd->sc_data_direction != DMA_FROM_DEVICE &&
817 	    scmnd->sc_data_direction != DMA_TO_DEVICE) {
818 		shost_printk(KERN_WARNING, target->scsi_host,
819 			     PFX "Unhandled data direction %d\n",
820 			     scmnd->sc_data_direction);
821 		return -EINVAL;
822 	}
823 
824 	nents = scsi_sg_count(scmnd);
825 	scat  = scsi_sglist(scmnd);
826 
827 	dev = target->srp_host->srp_dev;
828 	ibdev = dev->dev;
829 
830 	count = ib_dma_map_sg(ibdev, scat, nents, scmnd->sc_data_direction);
831 	if (unlikely(count == 0))
832 		return -EIO;
833 
834 	fmt = SRP_DATA_DESC_DIRECT;
835 	len = sizeof (struct srp_cmd) +	sizeof (struct srp_direct_buf);
836 
837 	if (count == 1) {
838 		/*
839 		 * The midlayer only generated a single gather/scatter
840 		 * entry, or DMA mapping coalesced everything to a
841 		 * single entry.  So a direct descriptor along with
842 		 * the DMA MR suffices.
843 		 */
844 		struct srp_direct_buf *buf = (void *) cmd->add_data;
845 
846 		buf->va  = cpu_to_be64(ib_sg_dma_address(ibdev, scat));
847 		buf->key = cpu_to_be32(target->rkey);
848 		buf->len = cpu_to_be32(ib_sg_dma_len(ibdev, scat));
849 
850 		req->nfmr = 0;
851 		goto map_complete;
852 	}
853 
854 	/* We have more than one scatter/gather entry, so build our indirect
855 	 * descriptor table, trying to merge as many entries with FMR as we
856 	 * can.
857 	 */
858 	indirect_hdr = (void *) cmd->add_data;
859 
860 	ib_dma_sync_single_for_cpu(ibdev, req->indirect_dma_addr,
861 				   target->indirect_size, DMA_TO_DEVICE);
862 
863 	memset(&state, 0, sizeof(state));
864 	state.desc	= req->indirect_desc;
865 	state.pages	= req->map_page;
866 	state.next_fmr	= req->fmr_list;
867 
868 	use_fmr = dev->fmr_pool ? SRP_MAP_ALLOW_FMR : SRP_MAP_NO_FMR;
869 
870 	for_each_sg(scat, sg, count, i) {
871 		if (srp_map_sg_entry(&state, target, sg, i, use_fmr)) {
872 			/* FMR mapping failed, so backtrack to the first
873 			 * unmapped entry and continue on without using FMR.
874 			 */
875 			dma_addr_t dma_addr;
876 			unsigned int dma_len;
877 
878 backtrack:
879 			sg = state.unmapped_sg;
880 			i = state.unmapped_index;
881 
882 			dma_addr = ib_sg_dma_address(ibdev, sg);
883 			dma_len = ib_sg_dma_len(ibdev, sg);
884 			dma_len -= (state.unmapped_addr - dma_addr);
885 			dma_addr = state.unmapped_addr;
886 			use_fmr = SRP_MAP_NO_FMR;
887 			srp_map_desc(&state, dma_addr, dma_len, target->rkey);
888 		}
889 	}
890 
891 	if (use_fmr == SRP_MAP_ALLOW_FMR && srp_map_finish_fmr(&state, target))
892 		goto backtrack;
893 
894 	/* We've mapped the request, now pull as much of the indirect
895 	 * descriptor table as we can into the command buffer. If this
896 	 * target is not using an external indirect table, we are
897 	 * guaranteed to fit into the command, as the SCSI layer won't
898 	 * give us more S/G entries than we allow.
899 	 */
900 	req->nfmr = state.nfmr;
901 	if (state.ndesc == 1) {
902 		/* FMR mapping was able to collapse this to one entry,
903 		 * so use a direct descriptor.
904 		 */
905 		struct srp_direct_buf *buf = (void *) cmd->add_data;
906 
907 		*buf = req->indirect_desc[0];
908 		goto map_complete;
909 	}
910 
911 	if (unlikely(target->cmd_sg_cnt < state.ndesc &&
912 						!target->allow_ext_sg)) {
913 		shost_printk(KERN_ERR, target->scsi_host,
914 			     "Could not fit S/G list into SRP_CMD\n");
915 		return -EIO;
916 	}
917 
918 	count = min(state.ndesc, target->cmd_sg_cnt);
919 	table_len = state.ndesc * sizeof (struct srp_direct_buf);
920 
921 	fmt = SRP_DATA_DESC_INDIRECT;
922 	len = sizeof(struct srp_cmd) + sizeof (struct srp_indirect_buf);
923 	len += count * sizeof (struct srp_direct_buf);
924 
925 	memcpy(indirect_hdr->desc_list, req->indirect_desc,
926 	       count * sizeof (struct srp_direct_buf));
927 
928 	indirect_hdr->table_desc.va = cpu_to_be64(req->indirect_dma_addr);
929 	indirect_hdr->table_desc.key = cpu_to_be32(target->rkey);
930 	indirect_hdr->table_desc.len = cpu_to_be32(table_len);
931 	indirect_hdr->len = cpu_to_be32(state.total_len);
932 
933 	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
934 		cmd->data_out_desc_cnt = count;
935 	else
936 		cmd->data_in_desc_cnt = count;
937 
938 	ib_dma_sync_single_for_device(ibdev, req->indirect_dma_addr, table_len,
939 				      DMA_TO_DEVICE);
940 
941 map_complete:
942 	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
943 		cmd->buf_fmt = fmt << 4;
944 	else
945 		cmd->buf_fmt = fmt;
946 
947 	return len;
948 }
949 
950 /*
951  * Return an IU and possible credit to the free pool
952  */
953 static void srp_put_tx_iu(struct srp_target_port *target, struct srp_iu *iu,
954 			  enum srp_iu_type iu_type)
955 {
956 	unsigned long flags;
957 
958 	spin_lock_irqsave(&target->lock, flags);
959 	list_add(&iu->list, &target->free_tx);
960 	if (iu_type != SRP_IU_RSP)
961 		++target->req_lim;
962 	spin_unlock_irqrestore(&target->lock, flags);
963 }
964 
965 /*
966  * Must be called with target->lock held to protect req_lim and free_tx.
967  * If IU is not sent, it must be returned using srp_put_tx_iu().
968  *
969  * Note:
970  * An upper limit for the number of allocated information units for each
971  * request type is:
972  * - SRP_IU_CMD: SRP_CMD_SQ_SIZE, since the SCSI mid-layer never queues
973  *   more than Scsi_Host.can_queue requests.
974  * - SRP_IU_TSK_MGMT: SRP_TSK_MGMT_SQ_SIZE.
975  * - SRP_IU_RSP: 1, since a conforming SRP target never sends more than
976  *   one unanswered SRP request to an initiator.
977  */
978 static struct srp_iu *__srp_get_tx_iu(struct srp_target_port *target,
979 				      enum srp_iu_type iu_type)
980 {
981 	s32 rsv = (iu_type == SRP_IU_TSK_MGMT) ? 0 : SRP_TSK_MGMT_SQ_SIZE;
982 	struct srp_iu *iu;
983 
984 	srp_send_completion(target->send_cq, target);
985 
986 	if (list_empty(&target->free_tx))
987 		return NULL;
988 
989 	/* Initiator responses to target requests do not consume credits */
990 	if (iu_type != SRP_IU_RSP) {
991 		if (target->req_lim <= rsv) {
992 			++target->zero_req_lim;
993 			return NULL;
994 		}
995 
996 		--target->req_lim;
997 	}
998 
999 	iu = list_first_entry(&target->free_tx, struct srp_iu, list);
1000 	list_del(&iu->list);
1001 	return iu;
1002 }
1003 
1004 static int srp_post_send(struct srp_target_port *target,
1005 			 struct srp_iu *iu, int len)
1006 {
1007 	struct ib_sge list;
1008 	struct ib_send_wr wr, *bad_wr;
1009 
1010 	list.addr   = iu->dma;
1011 	list.length = len;
1012 	list.lkey   = target->lkey;
1013 
1014 	wr.next       = NULL;
1015 	wr.wr_id      = (uintptr_t) iu;
1016 	wr.sg_list    = &list;
1017 	wr.num_sge    = 1;
1018 	wr.opcode     = IB_WR_SEND;
1019 	wr.send_flags = IB_SEND_SIGNALED;
1020 
1021 	return ib_post_send(target->qp, &wr, &bad_wr);
1022 }
1023 
1024 static int srp_post_recv(struct srp_target_port *target, struct srp_iu *iu)
1025 {
1026 	struct ib_recv_wr wr, *bad_wr;
1027 	struct ib_sge list;
1028 
1029 	list.addr   = iu->dma;
1030 	list.length = iu->size;
1031 	list.lkey   = target->lkey;
1032 
1033 	wr.next     = NULL;
1034 	wr.wr_id    = (uintptr_t) iu;
1035 	wr.sg_list  = &list;
1036 	wr.num_sge  = 1;
1037 
1038 	return ib_post_recv(target->qp, &wr, &bad_wr);
1039 }
1040 
1041 static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
1042 {
1043 	struct srp_request *req;
1044 	struct scsi_cmnd *scmnd;
1045 	unsigned long flags;
1046 
1047 	if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
1048 		spin_lock_irqsave(&target->lock, flags);
1049 		target->req_lim += be32_to_cpu(rsp->req_lim_delta);
1050 		spin_unlock_irqrestore(&target->lock, flags);
1051 
1052 		target->tsk_mgmt_status = -1;
1053 		if (be32_to_cpu(rsp->resp_data_len) >= 4)
1054 			target->tsk_mgmt_status = rsp->data[3];
1055 		complete(&target->tsk_mgmt_done);
1056 	} else {
1057 		req = &target->req_ring[rsp->tag];
1058 		scmnd = req->scmnd;
1059 		if (!scmnd)
1060 			shost_printk(KERN_ERR, target->scsi_host,
1061 				     "Null scmnd for RSP w/tag %016llx\n",
1062 				     (unsigned long long) rsp->tag);
1063 		scmnd->result = rsp->status;
1064 
1065 		if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
1066 			memcpy(scmnd->sense_buffer, rsp->data +
1067 			       be32_to_cpu(rsp->resp_data_len),
1068 			       min_t(int, be32_to_cpu(rsp->sense_data_len),
1069 				     SCSI_SENSE_BUFFERSIZE));
1070 		}
1071 
1072 		if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
1073 			scsi_set_resid(scmnd, be32_to_cpu(rsp->data_out_res_cnt));
1074 		else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
1075 			scsi_set_resid(scmnd, be32_to_cpu(rsp->data_in_res_cnt));
1076 
1077 		srp_remove_req(target, req, be32_to_cpu(rsp->req_lim_delta));
1078 		scmnd->host_scribble = NULL;
1079 		scmnd->scsi_done(scmnd);
1080 	}
1081 }
1082 
1083 static int srp_response_common(struct srp_target_port *target, s32 req_delta,
1084 			       void *rsp, int len)
1085 {
1086 	struct ib_device *dev = target->srp_host->srp_dev->dev;
1087 	unsigned long flags;
1088 	struct srp_iu *iu;
1089 	int err;
1090 
1091 	spin_lock_irqsave(&target->lock, flags);
1092 	target->req_lim += req_delta;
1093 	iu = __srp_get_tx_iu(target, SRP_IU_RSP);
1094 	spin_unlock_irqrestore(&target->lock, flags);
1095 
1096 	if (!iu) {
1097 		shost_printk(KERN_ERR, target->scsi_host, PFX
1098 			     "no IU available to send response\n");
1099 		return 1;
1100 	}
1101 
1102 	ib_dma_sync_single_for_cpu(dev, iu->dma, len, DMA_TO_DEVICE);
1103 	memcpy(iu->buf, rsp, len);
1104 	ib_dma_sync_single_for_device(dev, iu->dma, len, DMA_TO_DEVICE);
1105 
1106 	err = srp_post_send(target, iu, len);
1107 	if (err) {
1108 		shost_printk(KERN_ERR, target->scsi_host, PFX
1109 			     "unable to post response: %d\n", err);
1110 		srp_put_tx_iu(target, iu, SRP_IU_RSP);
1111 	}
1112 
1113 	return err;
1114 }
1115 
1116 static void srp_process_cred_req(struct srp_target_port *target,
1117 				 struct srp_cred_req *req)
1118 {
1119 	struct srp_cred_rsp rsp = {
1120 		.opcode = SRP_CRED_RSP,
1121 		.tag = req->tag,
1122 	};
1123 	s32 delta = be32_to_cpu(req->req_lim_delta);
1124 
1125 	if (srp_response_common(target, delta, &rsp, sizeof rsp))
1126 		shost_printk(KERN_ERR, target->scsi_host, PFX
1127 			     "problems processing SRP_CRED_REQ\n");
1128 }
1129 
1130 static void srp_process_aer_req(struct srp_target_port *target,
1131 				struct srp_aer_req *req)
1132 {
1133 	struct srp_aer_rsp rsp = {
1134 		.opcode = SRP_AER_RSP,
1135 		.tag = req->tag,
1136 	};
1137 	s32 delta = be32_to_cpu(req->req_lim_delta);
1138 
1139 	shost_printk(KERN_ERR, target->scsi_host, PFX
1140 		     "ignoring AER for LUN %llu\n", be64_to_cpu(req->lun));
1141 
1142 	if (srp_response_common(target, delta, &rsp, sizeof rsp))
1143 		shost_printk(KERN_ERR, target->scsi_host, PFX
1144 			     "problems processing SRP_AER_REQ\n");
1145 }
1146 
1147 static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
1148 {
1149 	struct ib_device *dev = target->srp_host->srp_dev->dev;
1150 	struct srp_iu *iu = (struct srp_iu *) (uintptr_t) wc->wr_id;
1151 	int res;
1152 	u8 opcode;
1153 
1154 	ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_ti_iu_len,
1155 				   DMA_FROM_DEVICE);
1156 
1157 	opcode = *(u8 *) iu->buf;
1158 
1159 	if (0) {
1160 		shost_printk(KERN_ERR, target->scsi_host,
1161 			     PFX "recv completion, opcode 0x%02x\n", opcode);
1162 		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 8, 1,
1163 			       iu->buf, wc->byte_len, true);
1164 	}
1165 
1166 	switch (opcode) {
1167 	case SRP_RSP:
1168 		srp_process_rsp(target, iu->buf);
1169 		break;
1170 
1171 	case SRP_CRED_REQ:
1172 		srp_process_cred_req(target, iu->buf);
1173 		break;
1174 
1175 	case SRP_AER_REQ:
1176 		srp_process_aer_req(target, iu->buf);
1177 		break;
1178 
1179 	case SRP_T_LOGOUT:
1180 		/* XXX Handle target logout */
1181 		shost_printk(KERN_WARNING, target->scsi_host,
1182 			     PFX "Got target logout request\n");
1183 		break;
1184 
1185 	default:
1186 		shost_printk(KERN_WARNING, target->scsi_host,
1187 			     PFX "Unhandled SRP opcode 0x%02x\n", opcode);
1188 		break;
1189 	}
1190 
1191 	ib_dma_sync_single_for_device(dev, iu->dma, target->max_ti_iu_len,
1192 				      DMA_FROM_DEVICE);
1193 
1194 	res = srp_post_recv(target, iu);
1195 	if (res != 0)
1196 		shost_printk(KERN_ERR, target->scsi_host,
1197 			     PFX "Recv failed with error code %d\n", res);
1198 }
1199 
1200 static void srp_recv_completion(struct ib_cq *cq, void *target_ptr)
1201 {
1202 	struct srp_target_port *target = target_ptr;
1203 	struct ib_wc wc;
1204 
1205 	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1206 	while (ib_poll_cq(cq, 1, &wc) > 0) {
1207 		if (wc.status) {
1208 			shost_printk(KERN_ERR, target->scsi_host,
1209 				     PFX "failed receive status %d\n",
1210 				     wc.status);
1211 			target->qp_in_error = 1;
1212 			break;
1213 		}
1214 
1215 		srp_handle_recv(target, &wc);
1216 	}
1217 }
1218 
1219 static void srp_send_completion(struct ib_cq *cq, void *target_ptr)
1220 {
1221 	struct srp_target_port *target = target_ptr;
1222 	struct ib_wc wc;
1223 	struct srp_iu *iu;
1224 
1225 	while (ib_poll_cq(cq, 1, &wc) > 0) {
1226 		if (wc.status) {
1227 			shost_printk(KERN_ERR, target->scsi_host,
1228 				     PFX "failed send status %d\n",
1229 				     wc.status);
1230 			target->qp_in_error = 1;
1231 			break;
1232 		}
1233 
1234 		iu = (struct srp_iu *) (uintptr_t) wc.wr_id;
1235 		list_add(&iu->list, &target->free_tx);
1236 	}
1237 }
1238 
1239 static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
1240 {
1241 	struct srp_target_port *target = host_to_target(shost);
1242 	struct srp_request *req;
1243 	struct srp_iu *iu;
1244 	struct srp_cmd *cmd;
1245 	struct ib_device *dev;
1246 	unsigned long flags;
1247 	int len;
1248 
1249 	if (target->state == SRP_TARGET_CONNECTING)
1250 		goto err;
1251 
1252 	if (target->state == SRP_TARGET_DEAD ||
1253 	    target->state == SRP_TARGET_REMOVED) {
1254 		scmnd->result = DID_BAD_TARGET << 16;
1255 		scmnd->scsi_done(scmnd);
1256 		return 0;
1257 	}
1258 
1259 	spin_lock_irqsave(&target->lock, flags);
1260 	iu = __srp_get_tx_iu(target, SRP_IU_CMD);
1261 	if (!iu)
1262 		goto err_unlock;
1263 
1264 	req = list_first_entry(&target->free_reqs, struct srp_request, list);
1265 	list_del(&req->list);
1266 	spin_unlock_irqrestore(&target->lock, flags);
1267 
1268 	dev = target->srp_host->srp_dev->dev;
1269 	ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_iu_len,
1270 				   DMA_TO_DEVICE);
1271 
1272 	scmnd->result        = 0;
1273 	scmnd->host_scribble = (void *) req;
1274 
1275 	cmd = iu->buf;
1276 	memset(cmd, 0, sizeof *cmd);
1277 
1278 	cmd->opcode = SRP_CMD;
1279 	cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
1280 	cmd->tag    = req->index;
1281 	memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
1282 
1283 	req->scmnd    = scmnd;
1284 	req->cmd      = iu;
1285 
1286 	len = srp_map_data(scmnd, target, req);
1287 	if (len < 0) {
1288 		shost_printk(KERN_ERR, target->scsi_host,
1289 			     PFX "Failed to map data\n");
1290 		goto err_iu;
1291 	}
1292 
1293 	ib_dma_sync_single_for_device(dev, iu->dma, target->max_iu_len,
1294 				      DMA_TO_DEVICE);
1295 
1296 	if (srp_post_send(target, iu, len)) {
1297 		shost_printk(KERN_ERR, target->scsi_host, PFX "Send failed\n");
1298 		goto err_unmap;
1299 	}
1300 
1301 	return 0;
1302 
1303 err_unmap:
1304 	srp_unmap_data(scmnd, target, req);
1305 
1306 err_iu:
1307 	srp_put_tx_iu(target, iu, SRP_IU_CMD);
1308 
1309 	spin_lock_irqsave(&target->lock, flags);
1310 	list_add(&req->list, &target->free_reqs);
1311 
1312 err_unlock:
1313 	spin_unlock_irqrestore(&target->lock, flags);
1314 
1315 err:
1316 	return SCSI_MLQUEUE_HOST_BUSY;
1317 }
1318 
1319 static int srp_alloc_iu_bufs(struct srp_target_port *target)
1320 {
1321 	int i;
1322 
1323 	for (i = 0; i < SRP_RQ_SIZE; ++i) {
1324 		target->rx_ring[i] = srp_alloc_iu(target->srp_host,
1325 						  target->max_ti_iu_len,
1326 						  GFP_KERNEL, DMA_FROM_DEVICE);
1327 		if (!target->rx_ring[i])
1328 			goto err;
1329 	}
1330 
1331 	for (i = 0; i < SRP_SQ_SIZE; ++i) {
1332 		target->tx_ring[i] = srp_alloc_iu(target->srp_host,
1333 						  target->max_iu_len,
1334 						  GFP_KERNEL, DMA_TO_DEVICE);
1335 		if (!target->tx_ring[i])
1336 			goto err;
1337 
1338 		list_add(&target->tx_ring[i]->list, &target->free_tx);
1339 	}
1340 
1341 	return 0;
1342 
1343 err:
1344 	for (i = 0; i < SRP_RQ_SIZE; ++i) {
1345 		srp_free_iu(target->srp_host, target->rx_ring[i]);
1346 		target->rx_ring[i] = NULL;
1347 	}
1348 
1349 	for (i = 0; i < SRP_SQ_SIZE; ++i) {
1350 		srp_free_iu(target->srp_host, target->tx_ring[i]);
1351 		target->tx_ring[i] = NULL;
1352 	}
1353 
1354 	return -ENOMEM;
1355 }
1356 
1357 static void srp_cm_rep_handler(struct ib_cm_id *cm_id,
1358 			       struct srp_login_rsp *lrsp,
1359 			       struct srp_target_port *target)
1360 {
1361 	struct ib_qp_attr *qp_attr = NULL;
1362 	int attr_mask = 0;
1363 	int ret;
1364 	int i;
1365 
1366 	if (lrsp->opcode == SRP_LOGIN_RSP) {
1367 		target->max_ti_iu_len = be32_to_cpu(lrsp->max_ti_iu_len);
1368 		target->req_lim       = be32_to_cpu(lrsp->req_lim_delta);
1369 
1370 		/*
1371 		 * Reserve credits for task management so we don't
1372 		 * bounce requests back to the SCSI mid-layer.
1373 		 */
1374 		target->scsi_host->can_queue
1375 			= min(target->req_lim - SRP_TSK_MGMT_SQ_SIZE,
1376 			      target->scsi_host->can_queue);
1377 	} else {
1378 		shost_printk(KERN_WARNING, target->scsi_host,
1379 			     PFX "Unhandled RSP opcode %#x\n", lrsp->opcode);
1380 		ret = -ECONNRESET;
1381 		goto error;
1382 	}
1383 
1384 	if (!target->rx_ring[0]) {
1385 		ret = srp_alloc_iu_bufs(target);
1386 		if (ret)
1387 			goto error;
1388 	}
1389 
1390 	ret = -ENOMEM;
1391 	qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
1392 	if (!qp_attr)
1393 		goto error;
1394 
1395 	qp_attr->qp_state = IB_QPS_RTR;
1396 	ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1397 	if (ret)
1398 		goto error_free;
1399 
1400 	ret = ib_modify_qp(target->qp, qp_attr, attr_mask);
1401 	if (ret)
1402 		goto error_free;
1403 
1404 	for (i = 0; i < SRP_RQ_SIZE; i++) {
1405 		struct srp_iu *iu = target->rx_ring[i];
1406 		ret = srp_post_recv(target, iu);
1407 		if (ret)
1408 			goto error_free;
1409 	}
1410 
1411 	qp_attr->qp_state = IB_QPS_RTS;
1412 	ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1413 	if (ret)
1414 		goto error_free;
1415 
1416 	ret = ib_modify_qp(target->qp, qp_attr, attr_mask);
1417 	if (ret)
1418 		goto error_free;
1419 
1420 	ret = ib_send_cm_rtu(cm_id, NULL, 0);
1421 
1422 error_free:
1423 	kfree(qp_attr);
1424 
1425 error:
1426 	target->status = ret;
1427 }
1428 
1429 static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
1430 			       struct ib_cm_event *event,
1431 			       struct srp_target_port *target)
1432 {
1433 	struct Scsi_Host *shost = target->scsi_host;
1434 	struct ib_class_port_info *cpi;
1435 	int opcode;
1436 
1437 	switch (event->param.rej_rcvd.reason) {
1438 	case IB_CM_REJ_PORT_CM_REDIRECT:
1439 		cpi = event->param.rej_rcvd.ari;
1440 		target->path.dlid = cpi->redirect_lid;
1441 		target->path.pkey = cpi->redirect_pkey;
1442 		cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
1443 		memcpy(target->path.dgid.raw, cpi->redirect_gid, 16);
1444 
1445 		target->status = target->path.dlid ?
1446 			SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
1447 		break;
1448 
1449 	case IB_CM_REJ_PORT_REDIRECT:
1450 		if (srp_target_is_topspin(target)) {
1451 			/*
1452 			 * Topspin/Cisco SRP gateways incorrectly send
1453 			 * reject reason code 25 when they mean 24
1454 			 * (port redirect).
1455 			 */
1456 			memcpy(target->path.dgid.raw,
1457 			       event->param.rej_rcvd.ari, 16);
1458 
1459 			shost_printk(KERN_DEBUG, shost,
1460 				     PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
1461 				     (unsigned long long) be64_to_cpu(target->path.dgid.global.subnet_prefix),
1462 				     (unsigned long long) be64_to_cpu(target->path.dgid.global.interface_id));
1463 
1464 			target->status = SRP_PORT_REDIRECT;
1465 		} else {
1466 			shost_printk(KERN_WARNING, shost,
1467 				     "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
1468 			target->status = -ECONNRESET;
1469 		}
1470 		break;
1471 
1472 	case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
1473 		shost_printk(KERN_WARNING, shost,
1474 			    "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
1475 		target->status = -ECONNRESET;
1476 		break;
1477 
1478 	case IB_CM_REJ_CONSUMER_DEFINED:
1479 		opcode = *(u8 *) event->private_data;
1480 		if (opcode == SRP_LOGIN_REJ) {
1481 			struct srp_login_rej *rej = event->private_data;
1482 			u32 reason = be32_to_cpu(rej->reason);
1483 
1484 			if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
1485 				shost_printk(KERN_WARNING, shost,
1486 					     PFX "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
1487 			else
1488 				shost_printk(KERN_WARNING, shost,
1489 					    PFX "SRP LOGIN REJECTED, reason 0x%08x\n", reason);
1490 		} else
1491 			shost_printk(KERN_WARNING, shost,
1492 				     "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
1493 				     " opcode 0x%02x\n", opcode);
1494 		target->status = -ECONNRESET;
1495 		break;
1496 
1497 	case IB_CM_REJ_STALE_CONN:
1498 		shost_printk(KERN_WARNING, shost, "  REJ reason: stale connection\n");
1499 		target->status = SRP_STALE_CONN;
1500 		break;
1501 
1502 	default:
1503 		shost_printk(KERN_WARNING, shost, "  REJ reason 0x%x\n",
1504 			     event->param.rej_rcvd.reason);
1505 		target->status = -ECONNRESET;
1506 	}
1507 }
1508 
1509 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
1510 {
1511 	struct srp_target_port *target = cm_id->context;
1512 	int comp = 0;
1513 
1514 	switch (event->event) {
1515 	case IB_CM_REQ_ERROR:
1516 		shost_printk(KERN_DEBUG, target->scsi_host,
1517 			     PFX "Sending CM REQ failed\n");
1518 		comp = 1;
1519 		target->status = -ECONNRESET;
1520 		break;
1521 
1522 	case IB_CM_REP_RECEIVED:
1523 		comp = 1;
1524 		srp_cm_rep_handler(cm_id, event->private_data, target);
1525 		break;
1526 
1527 	case IB_CM_REJ_RECEIVED:
1528 		shost_printk(KERN_DEBUG, target->scsi_host, PFX "REJ received\n");
1529 		comp = 1;
1530 
1531 		srp_cm_rej_handler(cm_id, event, target);
1532 		break;
1533 
1534 	case IB_CM_DREQ_RECEIVED:
1535 		shost_printk(KERN_WARNING, target->scsi_host,
1536 			     PFX "DREQ received - connection closed\n");
1537 		if (ib_send_cm_drep(cm_id, NULL, 0))
1538 			shost_printk(KERN_ERR, target->scsi_host,
1539 				     PFX "Sending CM DREP failed\n");
1540 		break;
1541 
1542 	case IB_CM_TIMEWAIT_EXIT:
1543 		shost_printk(KERN_ERR, target->scsi_host,
1544 			     PFX "connection closed\n");
1545 
1546 		comp = 1;
1547 		target->status = 0;
1548 		break;
1549 
1550 	case IB_CM_MRA_RECEIVED:
1551 	case IB_CM_DREQ_ERROR:
1552 	case IB_CM_DREP_RECEIVED:
1553 		break;
1554 
1555 	default:
1556 		shost_printk(KERN_WARNING, target->scsi_host,
1557 			     PFX "Unhandled CM event %d\n", event->event);
1558 		break;
1559 	}
1560 
1561 	if (comp)
1562 		complete(&target->done);
1563 
1564 	return 0;
1565 }
1566 
1567 static int srp_send_tsk_mgmt(struct srp_target_port *target,
1568 			     u64 req_tag, unsigned int lun, u8 func)
1569 {
1570 	struct ib_device *dev = target->srp_host->srp_dev->dev;
1571 	struct srp_iu *iu;
1572 	struct srp_tsk_mgmt *tsk_mgmt;
1573 
1574 	if (target->state == SRP_TARGET_DEAD ||
1575 	    target->state == SRP_TARGET_REMOVED)
1576 		return -1;
1577 
1578 	init_completion(&target->tsk_mgmt_done);
1579 
1580 	spin_lock_irq(&target->lock);
1581 	iu = __srp_get_tx_iu(target, SRP_IU_TSK_MGMT);
1582 	spin_unlock_irq(&target->lock);
1583 
1584 	if (!iu)
1585 		return -1;
1586 
1587 	ib_dma_sync_single_for_cpu(dev, iu->dma, sizeof *tsk_mgmt,
1588 				   DMA_TO_DEVICE);
1589 	tsk_mgmt = iu->buf;
1590 	memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
1591 
1592 	tsk_mgmt->opcode 	= SRP_TSK_MGMT;
1593 	tsk_mgmt->lun		= cpu_to_be64((u64) lun << 48);
1594 	tsk_mgmt->tag		= req_tag | SRP_TAG_TSK_MGMT;
1595 	tsk_mgmt->tsk_mgmt_func = func;
1596 	tsk_mgmt->task_tag	= req_tag;
1597 
1598 	ib_dma_sync_single_for_device(dev, iu->dma, sizeof *tsk_mgmt,
1599 				      DMA_TO_DEVICE);
1600 	if (srp_post_send(target, iu, sizeof *tsk_mgmt)) {
1601 		srp_put_tx_iu(target, iu, SRP_IU_TSK_MGMT);
1602 		return -1;
1603 	}
1604 
1605 	if (!wait_for_completion_timeout(&target->tsk_mgmt_done,
1606 					 msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
1607 		return -1;
1608 
1609 	return 0;
1610 }
1611 
1612 static int srp_abort(struct scsi_cmnd *scmnd)
1613 {
1614 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1615 	struct srp_request *req = (struct srp_request *) scmnd->host_scribble;
1616 	int ret = SUCCESS;
1617 
1618 	shost_printk(KERN_ERR, target->scsi_host, "SRP abort called\n");
1619 
1620 	if (!req || target->qp_in_error)
1621 		return FAILED;
1622 	if (srp_send_tsk_mgmt(target, req->index, scmnd->device->lun,
1623 			      SRP_TSK_ABORT_TASK))
1624 		return FAILED;
1625 
1626 	if (req->scmnd) {
1627 		if (!target->tsk_mgmt_status) {
1628 			srp_remove_req(target, req, 0);
1629 			scmnd->result = DID_ABORT << 16;
1630 		} else
1631 			ret = FAILED;
1632 	}
1633 
1634 	return ret;
1635 }
1636 
1637 static int srp_reset_device(struct scsi_cmnd *scmnd)
1638 {
1639 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1640 	int i;
1641 
1642 	shost_printk(KERN_ERR, target->scsi_host, "SRP reset_device called\n");
1643 
1644 	if (target->qp_in_error)
1645 		return FAILED;
1646 	if (srp_send_tsk_mgmt(target, SRP_TAG_NO_REQ, scmnd->device->lun,
1647 			      SRP_TSK_LUN_RESET))
1648 		return FAILED;
1649 	if (target->tsk_mgmt_status)
1650 		return FAILED;
1651 
1652 	for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
1653 		struct srp_request *req = &target->req_ring[i];
1654 		if (req->scmnd && req->scmnd->device == scmnd->device)
1655 			srp_reset_req(target, req);
1656 	}
1657 
1658 	return SUCCESS;
1659 }
1660 
1661 static int srp_reset_host(struct scsi_cmnd *scmnd)
1662 {
1663 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1664 	int ret = FAILED;
1665 
1666 	shost_printk(KERN_ERR, target->scsi_host, PFX "SRP reset_host called\n");
1667 
1668 	if (!srp_reconnect_target(target))
1669 		ret = SUCCESS;
1670 
1671 	return ret;
1672 }
1673 
1674 static ssize_t show_id_ext(struct device *dev, struct device_attribute *attr,
1675 			   char *buf)
1676 {
1677 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1678 
1679 	if (target->state == SRP_TARGET_DEAD ||
1680 	    target->state == SRP_TARGET_REMOVED)
1681 		return -ENODEV;
1682 
1683 	return sprintf(buf, "0x%016llx\n",
1684 		       (unsigned long long) be64_to_cpu(target->id_ext));
1685 }
1686 
1687 static ssize_t show_ioc_guid(struct device *dev, struct device_attribute *attr,
1688 			     char *buf)
1689 {
1690 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1691 
1692 	if (target->state == SRP_TARGET_DEAD ||
1693 	    target->state == SRP_TARGET_REMOVED)
1694 		return -ENODEV;
1695 
1696 	return sprintf(buf, "0x%016llx\n",
1697 		       (unsigned long long) be64_to_cpu(target->ioc_guid));
1698 }
1699 
1700 static ssize_t show_service_id(struct device *dev,
1701 			       struct device_attribute *attr, char *buf)
1702 {
1703 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1704 
1705 	if (target->state == SRP_TARGET_DEAD ||
1706 	    target->state == SRP_TARGET_REMOVED)
1707 		return -ENODEV;
1708 
1709 	return sprintf(buf, "0x%016llx\n",
1710 		       (unsigned long long) be64_to_cpu(target->service_id));
1711 }
1712 
1713 static ssize_t show_pkey(struct device *dev, struct device_attribute *attr,
1714 			 char *buf)
1715 {
1716 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1717 
1718 	if (target->state == SRP_TARGET_DEAD ||
1719 	    target->state == SRP_TARGET_REMOVED)
1720 		return -ENODEV;
1721 
1722 	return sprintf(buf, "0x%04x\n", be16_to_cpu(target->path.pkey));
1723 }
1724 
1725 static ssize_t show_dgid(struct device *dev, struct device_attribute *attr,
1726 			 char *buf)
1727 {
1728 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1729 
1730 	if (target->state == SRP_TARGET_DEAD ||
1731 	    target->state == SRP_TARGET_REMOVED)
1732 		return -ENODEV;
1733 
1734 	return sprintf(buf, "%pI6\n", target->path.dgid.raw);
1735 }
1736 
1737 static ssize_t show_orig_dgid(struct device *dev,
1738 			      struct device_attribute *attr, char *buf)
1739 {
1740 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1741 
1742 	if (target->state == SRP_TARGET_DEAD ||
1743 	    target->state == SRP_TARGET_REMOVED)
1744 		return -ENODEV;
1745 
1746 	return sprintf(buf, "%pI6\n", target->orig_dgid);
1747 }
1748 
1749 static ssize_t show_req_lim(struct device *dev,
1750 			    struct device_attribute *attr, char *buf)
1751 {
1752 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1753 
1754 	if (target->state == SRP_TARGET_DEAD ||
1755 	    target->state == SRP_TARGET_REMOVED)
1756 		return -ENODEV;
1757 
1758 	return sprintf(buf, "%d\n", target->req_lim);
1759 }
1760 
1761 static ssize_t show_zero_req_lim(struct device *dev,
1762 				 struct device_attribute *attr, char *buf)
1763 {
1764 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1765 
1766 	if (target->state == SRP_TARGET_DEAD ||
1767 	    target->state == SRP_TARGET_REMOVED)
1768 		return -ENODEV;
1769 
1770 	return sprintf(buf, "%d\n", target->zero_req_lim);
1771 }
1772 
1773 static ssize_t show_local_ib_port(struct device *dev,
1774 				  struct device_attribute *attr, char *buf)
1775 {
1776 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1777 
1778 	return sprintf(buf, "%d\n", target->srp_host->port);
1779 }
1780 
1781 static ssize_t show_local_ib_device(struct device *dev,
1782 				    struct device_attribute *attr, char *buf)
1783 {
1784 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1785 
1786 	return sprintf(buf, "%s\n", target->srp_host->srp_dev->dev->name);
1787 }
1788 
1789 static ssize_t show_cmd_sg_entries(struct device *dev,
1790 				   struct device_attribute *attr, char *buf)
1791 {
1792 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1793 
1794 	return sprintf(buf, "%u\n", target->cmd_sg_cnt);
1795 }
1796 
1797 static ssize_t show_allow_ext_sg(struct device *dev,
1798 				 struct device_attribute *attr, char *buf)
1799 {
1800 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1801 
1802 	return sprintf(buf, "%s\n", target->allow_ext_sg ? "true" : "false");
1803 }
1804 
1805 static DEVICE_ATTR(id_ext,	    S_IRUGO, show_id_ext,	   NULL);
1806 static DEVICE_ATTR(ioc_guid,	    S_IRUGO, show_ioc_guid,	   NULL);
1807 static DEVICE_ATTR(service_id,	    S_IRUGO, show_service_id,	   NULL);
1808 static DEVICE_ATTR(pkey,	    S_IRUGO, show_pkey,		   NULL);
1809 static DEVICE_ATTR(dgid,	    S_IRUGO, show_dgid,		   NULL);
1810 static DEVICE_ATTR(orig_dgid,	    S_IRUGO, show_orig_dgid,	   NULL);
1811 static DEVICE_ATTR(req_lim,         S_IRUGO, show_req_lim,         NULL);
1812 static DEVICE_ATTR(zero_req_lim,    S_IRUGO, show_zero_req_lim,	   NULL);
1813 static DEVICE_ATTR(local_ib_port,   S_IRUGO, show_local_ib_port,   NULL);
1814 static DEVICE_ATTR(local_ib_device, S_IRUGO, show_local_ib_device, NULL);
1815 static DEVICE_ATTR(cmd_sg_entries,  S_IRUGO, show_cmd_sg_entries,  NULL);
1816 static DEVICE_ATTR(allow_ext_sg,    S_IRUGO, show_allow_ext_sg,    NULL);
1817 
1818 static struct device_attribute *srp_host_attrs[] = {
1819 	&dev_attr_id_ext,
1820 	&dev_attr_ioc_guid,
1821 	&dev_attr_service_id,
1822 	&dev_attr_pkey,
1823 	&dev_attr_dgid,
1824 	&dev_attr_orig_dgid,
1825 	&dev_attr_req_lim,
1826 	&dev_attr_zero_req_lim,
1827 	&dev_attr_local_ib_port,
1828 	&dev_attr_local_ib_device,
1829 	&dev_attr_cmd_sg_entries,
1830 	&dev_attr_allow_ext_sg,
1831 	NULL
1832 };
1833 
1834 static struct scsi_host_template srp_template = {
1835 	.module				= THIS_MODULE,
1836 	.name				= "InfiniBand SRP initiator",
1837 	.proc_name			= DRV_NAME,
1838 	.info				= srp_target_info,
1839 	.queuecommand			= srp_queuecommand,
1840 	.eh_abort_handler		= srp_abort,
1841 	.eh_device_reset_handler	= srp_reset_device,
1842 	.eh_host_reset_handler		= srp_reset_host,
1843 	.sg_tablesize			= SRP_DEF_SG_TABLESIZE,
1844 	.can_queue			= SRP_CMD_SQ_SIZE,
1845 	.this_id			= -1,
1846 	.cmd_per_lun			= SRP_CMD_SQ_SIZE,
1847 	.use_clustering			= ENABLE_CLUSTERING,
1848 	.shost_attrs			= srp_host_attrs
1849 };
1850 
1851 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
1852 {
1853 	struct srp_rport_identifiers ids;
1854 	struct srp_rport *rport;
1855 
1856 	sprintf(target->target_name, "SRP.T10:%016llX",
1857 		 (unsigned long long) be64_to_cpu(target->id_ext));
1858 
1859 	if (scsi_add_host(target->scsi_host, host->srp_dev->dev->dma_device))
1860 		return -ENODEV;
1861 
1862 	memcpy(ids.port_id, &target->id_ext, 8);
1863 	memcpy(ids.port_id + 8, &target->ioc_guid, 8);
1864 	ids.roles = SRP_RPORT_ROLE_TARGET;
1865 	rport = srp_rport_add(target->scsi_host, &ids);
1866 	if (IS_ERR(rport)) {
1867 		scsi_remove_host(target->scsi_host);
1868 		return PTR_ERR(rport);
1869 	}
1870 
1871 	spin_lock(&host->target_lock);
1872 	list_add_tail(&target->list, &host->target_list);
1873 	spin_unlock(&host->target_lock);
1874 
1875 	target->state = SRP_TARGET_LIVE;
1876 
1877 	scsi_scan_target(&target->scsi_host->shost_gendev,
1878 			 0, target->scsi_id, SCAN_WILD_CARD, 0);
1879 
1880 	return 0;
1881 }
1882 
1883 static void srp_release_dev(struct device *dev)
1884 {
1885 	struct srp_host *host =
1886 		container_of(dev, struct srp_host, dev);
1887 
1888 	complete(&host->released);
1889 }
1890 
1891 static struct class srp_class = {
1892 	.name    = "infiniband_srp",
1893 	.dev_release = srp_release_dev
1894 };
1895 
1896 /*
1897  * Target ports are added by writing
1898  *
1899  *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
1900  *     pkey=<P_Key>,service_id=<service ID>
1901  *
1902  * to the add_target sysfs attribute.
1903  */
1904 enum {
1905 	SRP_OPT_ERR		= 0,
1906 	SRP_OPT_ID_EXT		= 1 << 0,
1907 	SRP_OPT_IOC_GUID	= 1 << 1,
1908 	SRP_OPT_DGID		= 1 << 2,
1909 	SRP_OPT_PKEY		= 1 << 3,
1910 	SRP_OPT_SERVICE_ID	= 1 << 4,
1911 	SRP_OPT_MAX_SECT	= 1 << 5,
1912 	SRP_OPT_MAX_CMD_PER_LUN	= 1 << 6,
1913 	SRP_OPT_IO_CLASS	= 1 << 7,
1914 	SRP_OPT_INITIATOR_EXT	= 1 << 8,
1915 	SRP_OPT_CMD_SG_ENTRIES	= 1 << 9,
1916 	SRP_OPT_ALLOW_EXT_SG	= 1 << 10,
1917 	SRP_OPT_SG_TABLESIZE	= 1 << 11,
1918 	SRP_OPT_ALL		= (SRP_OPT_ID_EXT	|
1919 				   SRP_OPT_IOC_GUID	|
1920 				   SRP_OPT_DGID		|
1921 				   SRP_OPT_PKEY		|
1922 				   SRP_OPT_SERVICE_ID),
1923 };
1924 
1925 static const match_table_t srp_opt_tokens = {
1926 	{ SRP_OPT_ID_EXT,		"id_ext=%s" 		},
1927 	{ SRP_OPT_IOC_GUID,		"ioc_guid=%s" 		},
1928 	{ SRP_OPT_DGID,			"dgid=%s" 		},
1929 	{ SRP_OPT_PKEY,			"pkey=%x" 		},
1930 	{ SRP_OPT_SERVICE_ID,		"service_id=%s"		},
1931 	{ SRP_OPT_MAX_SECT,		"max_sect=%d" 		},
1932 	{ SRP_OPT_MAX_CMD_PER_LUN,	"max_cmd_per_lun=%d" 	},
1933 	{ SRP_OPT_IO_CLASS,		"io_class=%x"		},
1934 	{ SRP_OPT_INITIATOR_EXT,	"initiator_ext=%s"	},
1935 	{ SRP_OPT_CMD_SG_ENTRIES,	"cmd_sg_entries=%u"	},
1936 	{ SRP_OPT_ALLOW_EXT_SG,		"allow_ext_sg=%u"	},
1937 	{ SRP_OPT_SG_TABLESIZE,		"sg_tablesize=%u"	},
1938 	{ SRP_OPT_ERR,			NULL 			}
1939 };
1940 
1941 static int srp_parse_options(const char *buf, struct srp_target_port *target)
1942 {
1943 	char *options, *sep_opt;
1944 	char *p;
1945 	char dgid[3];
1946 	substring_t args[MAX_OPT_ARGS];
1947 	int opt_mask = 0;
1948 	int token;
1949 	int ret = -EINVAL;
1950 	int i;
1951 
1952 	options = kstrdup(buf, GFP_KERNEL);
1953 	if (!options)
1954 		return -ENOMEM;
1955 
1956 	sep_opt = options;
1957 	while ((p = strsep(&sep_opt, ",")) != NULL) {
1958 		if (!*p)
1959 			continue;
1960 
1961 		token = match_token(p, srp_opt_tokens, args);
1962 		opt_mask |= token;
1963 
1964 		switch (token) {
1965 		case SRP_OPT_ID_EXT:
1966 			p = match_strdup(args);
1967 			if (!p) {
1968 				ret = -ENOMEM;
1969 				goto out;
1970 			}
1971 			target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
1972 			kfree(p);
1973 			break;
1974 
1975 		case SRP_OPT_IOC_GUID:
1976 			p = match_strdup(args);
1977 			if (!p) {
1978 				ret = -ENOMEM;
1979 				goto out;
1980 			}
1981 			target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
1982 			kfree(p);
1983 			break;
1984 
1985 		case SRP_OPT_DGID:
1986 			p = match_strdup(args);
1987 			if (!p) {
1988 				ret = -ENOMEM;
1989 				goto out;
1990 			}
1991 			if (strlen(p) != 32) {
1992 				printk(KERN_WARNING PFX "bad dest GID parameter '%s'\n", p);
1993 				kfree(p);
1994 				goto out;
1995 			}
1996 
1997 			for (i = 0; i < 16; ++i) {
1998 				strlcpy(dgid, p + i * 2, 3);
1999 				target->path.dgid.raw[i] = simple_strtoul(dgid, NULL, 16);
2000 			}
2001 			kfree(p);
2002 			memcpy(target->orig_dgid, target->path.dgid.raw, 16);
2003 			break;
2004 
2005 		case SRP_OPT_PKEY:
2006 			if (match_hex(args, &token)) {
2007 				printk(KERN_WARNING PFX "bad P_Key parameter '%s'\n", p);
2008 				goto out;
2009 			}
2010 			target->path.pkey = cpu_to_be16(token);
2011 			break;
2012 
2013 		case SRP_OPT_SERVICE_ID:
2014 			p = match_strdup(args);
2015 			if (!p) {
2016 				ret = -ENOMEM;
2017 				goto out;
2018 			}
2019 			target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
2020 			target->path.service_id = target->service_id;
2021 			kfree(p);
2022 			break;
2023 
2024 		case SRP_OPT_MAX_SECT:
2025 			if (match_int(args, &token)) {
2026 				printk(KERN_WARNING PFX "bad max sect parameter '%s'\n", p);
2027 				goto out;
2028 			}
2029 			target->scsi_host->max_sectors = token;
2030 			break;
2031 
2032 		case SRP_OPT_MAX_CMD_PER_LUN:
2033 			if (match_int(args, &token)) {
2034 				printk(KERN_WARNING PFX "bad max cmd_per_lun parameter '%s'\n", p);
2035 				goto out;
2036 			}
2037 			target->scsi_host->cmd_per_lun = min(token, SRP_CMD_SQ_SIZE);
2038 			break;
2039 
2040 		case SRP_OPT_IO_CLASS:
2041 			if (match_hex(args, &token)) {
2042 				printk(KERN_WARNING PFX "bad  IO class parameter '%s' \n", p);
2043 				goto out;
2044 			}
2045 			if (token != SRP_REV10_IB_IO_CLASS &&
2046 			    token != SRP_REV16A_IB_IO_CLASS) {
2047 				printk(KERN_WARNING PFX "unknown IO class parameter value"
2048 				       " %x specified (use %x or %x).\n",
2049 				       token, SRP_REV10_IB_IO_CLASS, SRP_REV16A_IB_IO_CLASS);
2050 				goto out;
2051 			}
2052 			target->io_class = token;
2053 			break;
2054 
2055 		case SRP_OPT_INITIATOR_EXT:
2056 			p = match_strdup(args);
2057 			if (!p) {
2058 				ret = -ENOMEM;
2059 				goto out;
2060 			}
2061 			target->initiator_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
2062 			kfree(p);
2063 			break;
2064 
2065 		case SRP_OPT_CMD_SG_ENTRIES:
2066 			if (match_int(args, &token) || token < 1 || token > 255) {
2067 				printk(KERN_WARNING PFX "bad max cmd_sg_entries parameter '%s'\n", p);
2068 				goto out;
2069 			}
2070 			target->cmd_sg_cnt = token;
2071 			break;
2072 
2073 		case SRP_OPT_ALLOW_EXT_SG:
2074 			if (match_int(args, &token)) {
2075 				printk(KERN_WARNING PFX "bad allow_ext_sg parameter '%s'\n", p);
2076 				goto out;
2077 			}
2078 			target->allow_ext_sg = !!token;
2079 			break;
2080 
2081 		case SRP_OPT_SG_TABLESIZE:
2082 			if (match_int(args, &token) || token < 1 ||
2083 					token > SCSI_MAX_SG_CHAIN_SEGMENTS) {
2084 				printk(KERN_WARNING PFX "bad max sg_tablesize parameter '%s'\n", p);
2085 				goto out;
2086 			}
2087 			target->sg_tablesize = token;
2088 			break;
2089 
2090 		default:
2091 			printk(KERN_WARNING PFX "unknown parameter or missing value "
2092 			       "'%s' in target creation request\n", p);
2093 			goto out;
2094 		}
2095 	}
2096 
2097 	if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
2098 		ret = 0;
2099 	else
2100 		for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
2101 			if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
2102 			    !(srp_opt_tokens[i].token & opt_mask))
2103 				printk(KERN_WARNING PFX "target creation request is "
2104 				       "missing parameter '%s'\n",
2105 				       srp_opt_tokens[i].pattern);
2106 
2107 out:
2108 	kfree(options);
2109 	return ret;
2110 }
2111 
2112 static ssize_t srp_create_target(struct device *dev,
2113 				 struct device_attribute *attr,
2114 				 const char *buf, size_t count)
2115 {
2116 	struct srp_host *host =
2117 		container_of(dev, struct srp_host, dev);
2118 	struct Scsi_Host *target_host;
2119 	struct srp_target_port *target;
2120 	struct ib_device *ibdev = host->srp_dev->dev;
2121 	dma_addr_t dma_addr;
2122 	int i, ret;
2123 
2124 	target_host = scsi_host_alloc(&srp_template,
2125 				      sizeof (struct srp_target_port));
2126 	if (!target_host)
2127 		return -ENOMEM;
2128 
2129 	target_host->transportt  = ib_srp_transport_template;
2130 	target_host->max_channel = 0;
2131 	target_host->max_id      = 1;
2132 	target_host->max_lun     = SRP_MAX_LUN;
2133 	target_host->max_cmd_len = sizeof ((struct srp_cmd *) (void *) 0L)->cdb;
2134 
2135 	target = host_to_target(target_host);
2136 
2137 	target->io_class	= SRP_REV16A_IB_IO_CLASS;
2138 	target->scsi_host	= target_host;
2139 	target->srp_host	= host;
2140 	target->lkey		= host->srp_dev->mr->lkey;
2141 	target->rkey		= host->srp_dev->mr->rkey;
2142 	target->cmd_sg_cnt	= cmd_sg_entries;
2143 	target->sg_tablesize	= indirect_sg_entries ? : cmd_sg_entries;
2144 	target->allow_ext_sg	= allow_ext_sg;
2145 
2146 	ret = srp_parse_options(buf, target);
2147 	if (ret)
2148 		goto err;
2149 
2150 	if (!host->srp_dev->fmr_pool && !target->allow_ext_sg &&
2151 				target->cmd_sg_cnt < target->sg_tablesize) {
2152 		printk(KERN_WARNING PFX "No FMR pool and no external indirect descriptors, limiting sg_tablesize to cmd_sg_cnt\n");
2153 		target->sg_tablesize = target->cmd_sg_cnt;
2154 	}
2155 
2156 	target_host->sg_tablesize = target->sg_tablesize;
2157 	target->indirect_size = target->sg_tablesize *
2158 				sizeof (struct srp_direct_buf);
2159 	target->max_iu_len = sizeof (struct srp_cmd) +
2160 			     sizeof (struct srp_indirect_buf) +
2161 			     target->cmd_sg_cnt * sizeof (struct srp_direct_buf);
2162 
2163 	spin_lock_init(&target->lock);
2164 	INIT_LIST_HEAD(&target->free_tx);
2165 	INIT_LIST_HEAD(&target->free_reqs);
2166 	for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
2167 		struct srp_request *req = &target->req_ring[i];
2168 
2169 		req->fmr_list = kmalloc(target->cmd_sg_cnt * sizeof (void *),
2170 					GFP_KERNEL);
2171 		req->map_page = kmalloc(SRP_FMR_SIZE * sizeof (void *),
2172 					GFP_KERNEL);
2173 		req->indirect_desc = kmalloc(target->indirect_size, GFP_KERNEL);
2174 		if (!req->fmr_list || !req->map_page || !req->indirect_desc)
2175 			goto err_free_mem;
2176 
2177 		dma_addr = ib_dma_map_single(ibdev, req->indirect_desc,
2178 					     target->indirect_size,
2179 					     DMA_TO_DEVICE);
2180 		if (ib_dma_mapping_error(ibdev, dma_addr))
2181 			goto err_free_mem;
2182 
2183 		req->indirect_dma_addr = dma_addr;
2184 		req->index = i;
2185 		list_add_tail(&req->list, &target->free_reqs);
2186 	}
2187 
2188 	ib_query_gid(ibdev, host->port, 0, &target->path.sgid);
2189 
2190 	shost_printk(KERN_DEBUG, target->scsi_host, PFX
2191 		     "new target: id_ext %016llx ioc_guid %016llx pkey %04x "
2192 		     "service_id %016llx dgid %pI6\n",
2193 	       (unsigned long long) be64_to_cpu(target->id_ext),
2194 	       (unsigned long long) be64_to_cpu(target->ioc_guid),
2195 	       be16_to_cpu(target->path.pkey),
2196 	       (unsigned long long) be64_to_cpu(target->service_id),
2197 	       target->path.dgid.raw);
2198 
2199 	ret = srp_create_target_ib(target);
2200 	if (ret)
2201 		goto err_free_mem;
2202 
2203 	ret = srp_new_cm_id(target);
2204 	if (ret)
2205 		goto err_free_ib;
2206 
2207 	target->qp_in_error = 0;
2208 	ret = srp_connect_target(target);
2209 	if (ret) {
2210 		shost_printk(KERN_ERR, target->scsi_host,
2211 			     PFX "Connection failed\n");
2212 		goto err_cm_id;
2213 	}
2214 
2215 	ret = srp_add_target(host, target);
2216 	if (ret)
2217 		goto err_disconnect;
2218 
2219 	return count;
2220 
2221 err_disconnect:
2222 	srp_disconnect_target(target);
2223 
2224 err_cm_id:
2225 	ib_destroy_cm_id(target->cm_id);
2226 
2227 err_free_ib:
2228 	srp_free_target_ib(target);
2229 
2230 err_free_mem:
2231 	srp_free_req_data(target);
2232 
2233 err:
2234 	scsi_host_put(target_host);
2235 
2236 	return ret;
2237 }
2238 
2239 static DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
2240 
2241 static ssize_t show_ibdev(struct device *dev, struct device_attribute *attr,
2242 			  char *buf)
2243 {
2244 	struct srp_host *host = container_of(dev, struct srp_host, dev);
2245 
2246 	return sprintf(buf, "%s\n", host->srp_dev->dev->name);
2247 }
2248 
2249 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
2250 
2251 static ssize_t show_port(struct device *dev, struct device_attribute *attr,
2252 			 char *buf)
2253 {
2254 	struct srp_host *host = container_of(dev, struct srp_host, dev);
2255 
2256 	return sprintf(buf, "%d\n", host->port);
2257 }
2258 
2259 static DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
2260 
2261 static struct srp_host *srp_add_port(struct srp_device *device, u8 port)
2262 {
2263 	struct srp_host *host;
2264 
2265 	host = kzalloc(sizeof *host, GFP_KERNEL);
2266 	if (!host)
2267 		return NULL;
2268 
2269 	INIT_LIST_HEAD(&host->target_list);
2270 	spin_lock_init(&host->target_lock);
2271 	init_completion(&host->released);
2272 	host->srp_dev = device;
2273 	host->port = port;
2274 
2275 	host->dev.class = &srp_class;
2276 	host->dev.parent = device->dev->dma_device;
2277 	dev_set_name(&host->dev, "srp-%s-%d", device->dev->name, port);
2278 
2279 	if (device_register(&host->dev))
2280 		goto free_host;
2281 	if (device_create_file(&host->dev, &dev_attr_add_target))
2282 		goto err_class;
2283 	if (device_create_file(&host->dev, &dev_attr_ibdev))
2284 		goto err_class;
2285 	if (device_create_file(&host->dev, &dev_attr_port))
2286 		goto err_class;
2287 
2288 	return host;
2289 
2290 err_class:
2291 	device_unregister(&host->dev);
2292 
2293 free_host:
2294 	kfree(host);
2295 
2296 	return NULL;
2297 }
2298 
2299 static void srp_add_one(struct ib_device *device)
2300 {
2301 	struct srp_device *srp_dev;
2302 	struct ib_device_attr *dev_attr;
2303 	struct ib_fmr_pool_param fmr_param;
2304 	struct srp_host *host;
2305 	int max_pages_per_fmr, fmr_page_shift, s, e, p;
2306 
2307 	dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
2308 	if (!dev_attr)
2309 		return;
2310 
2311 	if (ib_query_device(device, dev_attr)) {
2312 		printk(KERN_WARNING PFX "Query device failed for %s\n",
2313 		       device->name);
2314 		goto free_attr;
2315 	}
2316 
2317 	srp_dev = kmalloc(sizeof *srp_dev, GFP_KERNEL);
2318 	if (!srp_dev)
2319 		goto free_attr;
2320 
2321 	/*
2322 	 * Use the smallest page size supported by the HCA, down to a
2323 	 * minimum of 4096 bytes. We're unlikely to build large sglists
2324 	 * out of smaller entries.
2325 	 */
2326 	fmr_page_shift		= max(12, ffs(dev_attr->page_size_cap) - 1);
2327 	srp_dev->fmr_page_size	= 1 << fmr_page_shift;
2328 	srp_dev->fmr_page_mask	= ~((u64) srp_dev->fmr_page_size - 1);
2329 	srp_dev->fmr_max_size	= srp_dev->fmr_page_size * SRP_FMR_SIZE;
2330 
2331 	INIT_LIST_HEAD(&srp_dev->dev_list);
2332 
2333 	srp_dev->dev = device;
2334 	srp_dev->pd  = ib_alloc_pd(device);
2335 	if (IS_ERR(srp_dev->pd))
2336 		goto free_dev;
2337 
2338 	srp_dev->mr = ib_get_dma_mr(srp_dev->pd,
2339 				    IB_ACCESS_LOCAL_WRITE |
2340 				    IB_ACCESS_REMOTE_READ |
2341 				    IB_ACCESS_REMOTE_WRITE);
2342 	if (IS_ERR(srp_dev->mr))
2343 		goto err_pd;
2344 
2345 	for (max_pages_per_fmr = SRP_FMR_SIZE;
2346 			max_pages_per_fmr >= SRP_FMR_MIN_SIZE;
2347 			max_pages_per_fmr /= 2, srp_dev->fmr_max_size /= 2) {
2348 		memset(&fmr_param, 0, sizeof fmr_param);
2349 		fmr_param.pool_size	    = SRP_FMR_POOL_SIZE;
2350 		fmr_param.dirty_watermark   = SRP_FMR_DIRTY_SIZE;
2351 		fmr_param.cache		    = 1;
2352 		fmr_param.max_pages_per_fmr = max_pages_per_fmr;
2353 		fmr_param.page_shift	    = fmr_page_shift;
2354 		fmr_param.access	    = (IB_ACCESS_LOCAL_WRITE |
2355 					       IB_ACCESS_REMOTE_WRITE |
2356 					       IB_ACCESS_REMOTE_READ);
2357 
2358 		srp_dev->fmr_pool = ib_create_fmr_pool(srp_dev->pd, &fmr_param);
2359 		if (!IS_ERR(srp_dev->fmr_pool))
2360 			break;
2361 	}
2362 
2363 	if (IS_ERR(srp_dev->fmr_pool))
2364 		srp_dev->fmr_pool = NULL;
2365 
2366 	if (device->node_type == RDMA_NODE_IB_SWITCH) {
2367 		s = 0;
2368 		e = 0;
2369 	} else {
2370 		s = 1;
2371 		e = device->phys_port_cnt;
2372 	}
2373 
2374 	for (p = s; p <= e; ++p) {
2375 		host = srp_add_port(srp_dev, p);
2376 		if (host)
2377 			list_add_tail(&host->list, &srp_dev->dev_list);
2378 	}
2379 
2380 	ib_set_client_data(device, &srp_client, srp_dev);
2381 
2382 	goto free_attr;
2383 
2384 err_pd:
2385 	ib_dealloc_pd(srp_dev->pd);
2386 
2387 free_dev:
2388 	kfree(srp_dev);
2389 
2390 free_attr:
2391 	kfree(dev_attr);
2392 }
2393 
2394 static void srp_remove_one(struct ib_device *device)
2395 {
2396 	struct srp_device *srp_dev;
2397 	struct srp_host *host, *tmp_host;
2398 	LIST_HEAD(target_list);
2399 	struct srp_target_port *target, *tmp_target;
2400 
2401 	srp_dev = ib_get_client_data(device, &srp_client);
2402 
2403 	list_for_each_entry_safe(host, tmp_host, &srp_dev->dev_list, list) {
2404 		device_unregister(&host->dev);
2405 		/*
2406 		 * Wait for the sysfs entry to go away, so that no new
2407 		 * target ports can be created.
2408 		 */
2409 		wait_for_completion(&host->released);
2410 
2411 		/*
2412 		 * Mark all target ports as removed, so we stop queueing
2413 		 * commands and don't try to reconnect.
2414 		 */
2415 		spin_lock(&host->target_lock);
2416 		list_for_each_entry(target, &host->target_list, list) {
2417 			spin_lock_irq(&target->lock);
2418 			target->state = SRP_TARGET_REMOVED;
2419 			spin_unlock_irq(&target->lock);
2420 		}
2421 		spin_unlock(&host->target_lock);
2422 
2423 		/*
2424 		 * Wait for any reconnection tasks that may have
2425 		 * started before we marked our target ports as
2426 		 * removed, and any target port removal tasks.
2427 		 */
2428 		flush_workqueue(ib_wq);
2429 
2430 		list_for_each_entry_safe(target, tmp_target,
2431 					 &host->target_list, list) {
2432 			srp_remove_host(target->scsi_host);
2433 			scsi_remove_host(target->scsi_host);
2434 			srp_disconnect_target(target);
2435 			ib_destroy_cm_id(target->cm_id);
2436 			srp_free_target_ib(target);
2437 			srp_free_req_data(target);
2438 			scsi_host_put(target->scsi_host);
2439 		}
2440 
2441 		kfree(host);
2442 	}
2443 
2444 	if (srp_dev->fmr_pool)
2445 		ib_destroy_fmr_pool(srp_dev->fmr_pool);
2446 	ib_dereg_mr(srp_dev->mr);
2447 	ib_dealloc_pd(srp_dev->pd);
2448 
2449 	kfree(srp_dev);
2450 }
2451 
2452 static struct srp_function_template ib_srp_transport_functions = {
2453 };
2454 
2455 static int __init srp_init_module(void)
2456 {
2457 	int ret;
2458 
2459 	BUILD_BUG_ON(FIELD_SIZEOF(struct ib_wc, wr_id) < sizeof(void *));
2460 
2461 	if (srp_sg_tablesize) {
2462 		printk(KERN_WARNING PFX "srp_sg_tablesize is deprecated, please use cmd_sg_entries\n");
2463 		if (!cmd_sg_entries)
2464 			cmd_sg_entries = srp_sg_tablesize;
2465 	}
2466 
2467 	if (!cmd_sg_entries)
2468 		cmd_sg_entries = SRP_DEF_SG_TABLESIZE;
2469 
2470 	if (cmd_sg_entries > 255) {
2471 		printk(KERN_WARNING PFX "Clamping cmd_sg_entries to 255\n");
2472 		cmd_sg_entries = 255;
2473 	}
2474 
2475 	if (!indirect_sg_entries)
2476 		indirect_sg_entries = cmd_sg_entries;
2477 	else if (indirect_sg_entries < cmd_sg_entries) {
2478 		printk(KERN_WARNING PFX "Bumping up indirect_sg_entries to match cmd_sg_entries (%u)\n", cmd_sg_entries);
2479 		indirect_sg_entries = cmd_sg_entries;
2480 	}
2481 
2482 	ib_srp_transport_template =
2483 		srp_attach_transport(&ib_srp_transport_functions);
2484 	if (!ib_srp_transport_template)
2485 		return -ENOMEM;
2486 
2487 	ret = class_register(&srp_class);
2488 	if (ret) {
2489 		printk(KERN_ERR PFX "couldn't register class infiniband_srp\n");
2490 		srp_release_transport(ib_srp_transport_template);
2491 		return ret;
2492 	}
2493 
2494 	ib_sa_register_client(&srp_sa_client);
2495 
2496 	ret = ib_register_client(&srp_client);
2497 	if (ret) {
2498 		printk(KERN_ERR PFX "couldn't register IB client\n");
2499 		srp_release_transport(ib_srp_transport_template);
2500 		ib_sa_unregister_client(&srp_sa_client);
2501 		class_unregister(&srp_class);
2502 		return ret;
2503 	}
2504 
2505 	return 0;
2506 }
2507 
2508 static void __exit srp_cleanup_module(void)
2509 {
2510 	ib_unregister_client(&srp_client);
2511 	ib_sa_unregister_client(&srp_sa_client);
2512 	class_unregister(&srp_class);
2513 	srp_release_transport(ib_srp_transport_template);
2514 }
2515 
2516 module_init(srp_init_module);
2517 module_exit(srp_cleanup_module);
2518