xref: /openbmc/linux/drivers/infiniband/ulp/srp/ib_srp.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 <asm/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 int srp_sg_tablesize = SRP_DEF_SG_TABLESIZE;
63 static int srp_max_iu_len;
64 
65 module_param(srp_sg_tablesize, int, 0444);
66 MODULE_PARM_DESC(srp_sg_tablesize,
67 		 "Max number of gather/scatter entries per I/O (default is 12, max 255)");
68 
69 static int topspin_workarounds = 1;
70 
71 module_param(topspin_workarounds, int, 0444);
72 MODULE_PARM_DESC(topspin_workarounds,
73 		 "Enable workarounds for Topspin/Cisco SRP target bugs if != 0");
74 
75 static int mellanox_workarounds = 1;
76 
77 module_param(mellanox_workarounds, int, 0444);
78 MODULE_PARM_DESC(mellanox_workarounds,
79 		 "Enable workarounds for Mellanox SRP target bugs if != 0");
80 
81 static void srp_add_one(struct ib_device *device);
82 static void srp_remove_one(struct ib_device *device);
83 static void srp_recv_completion(struct ib_cq *cq, void *target_ptr);
84 static void srp_send_completion(struct ib_cq *cq, void *target_ptr);
85 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);
86 
87 static struct scsi_transport_template *ib_srp_transport_template;
88 
89 static struct ib_client srp_client = {
90 	.name   = "srp",
91 	.add    = srp_add_one,
92 	.remove = srp_remove_one
93 };
94 
95 static struct ib_sa_client srp_sa_client;
96 
97 static inline struct srp_target_port *host_to_target(struct Scsi_Host *host)
98 {
99 	return (struct srp_target_port *) host->hostdata;
100 }
101 
102 static const char *srp_target_info(struct Scsi_Host *host)
103 {
104 	return host_to_target(host)->target_name;
105 }
106 
107 static int srp_target_is_topspin(struct srp_target_port *target)
108 {
109 	static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
110 	static const u8 cisco_oui[3]   = { 0x00, 0x1b, 0x0d };
111 
112 	return topspin_workarounds &&
113 		(!memcmp(&target->ioc_guid, topspin_oui, sizeof topspin_oui) ||
114 		 !memcmp(&target->ioc_guid, cisco_oui, sizeof cisco_oui));
115 }
116 
117 static int srp_target_is_mellanox(struct srp_target_port *target)
118 {
119 	static const u8 mellanox_oui[3] = { 0x00, 0x02, 0xc9 };
120 
121 	return mellanox_workarounds &&
122 		!memcmp(&target->ioc_guid, mellanox_oui, sizeof mellanox_oui);
123 }
124 
125 static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
126 				   gfp_t gfp_mask,
127 				   enum dma_data_direction direction)
128 {
129 	struct srp_iu *iu;
130 
131 	iu = kmalloc(sizeof *iu, gfp_mask);
132 	if (!iu)
133 		goto out;
134 
135 	iu->buf = kzalloc(size, gfp_mask);
136 	if (!iu->buf)
137 		goto out_free_iu;
138 
139 	iu->dma = ib_dma_map_single(host->srp_dev->dev, iu->buf, size,
140 				    direction);
141 	if (ib_dma_mapping_error(host->srp_dev->dev, iu->dma))
142 		goto out_free_buf;
143 
144 	iu->size      = size;
145 	iu->direction = direction;
146 
147 	return iu;
148 
149 out_free_buf:
150 	kfree(iu->buf);
151 out_free_iu:
152 	kfree(iu);
153 out:
154 	return NULL;
155 }
156 
157 static void srp_free_iu(struct srp_host *host, struct srp_iu *iu)
158 {
159 	if (!iu)
160 		return;
161 
162 	ib_dma_unmap_single(host->srp_dev->dev, iu->dma, iu->size,
163 			    iu->direction);
164 	kfree(iu->buf);
165 	kfree(iu);
166 }
167 
168 static void srp_qp_event(struct ib_event *event, void *context)
169 {
170 	printk(KERN_ERR PFX "QP event %d\n", event->event);
171 }
172 
173 static int srp_init_qp(struct srp_target_port *target,
174 		       struct ib_qp *qp)
175 {
176 	struct ib_qp_attr *attr;
177 	int ret;
178 
179 	attr = kmalloc(sizeof *attr, GFP_KERNEL);
180 	if (!attr)
181 		return -ENOMEM;
182 
183 	ret = ib_find_pkey(target->srp_host->srp_dev->dev,
184 			   target->srp_host->port,
185 			   be16_to_cpu(target->path.pkey),
186 			   &attr->pkey_index);
187 	if (ret)
188 		goto out;
189 
190 	attr->qp_state        = IB_QPS_INIT;
191 	attr->qp_access_flags = (IB_ACCESS_REMOTE_READ |
192 				    IB_ACCESS_REMOTE_WRITE);
193 	attr->port_num        = target->srp_host->port;
194 
195 	ret = ib_modify_qp(qp, attr,
196 			   IB_QP_STATE		|
197 			   IB_QP_PKEY_INDEX	|
198 			   IB_QP_ACCESS_FLAGS	|
199 			   IB_QP_PORT);
200 
201 out:
202 	kfree(attr);
203 	return ret;
204 }
205 
206 static int srp_new_cm_id(struct srp_target_port *target)
207 {
208 	struct ib_cm_id *new_cm_id;
209 
210 	new_cm_id = ib_create_cm_id(target->srp_host->srp_dev->dev,
211 				    srp_cm_handler, target);
212 	if (IS_ERR(new_cm_id))
213 		return PTR_ERR(new_cm_id);
214 
215 	if (target->cm_id)
216 		ib_destroy_cm_id(target->cm_id);
217 	target->cm_id = new_cm_id;
218 
219 	return 0;
220 }
221 
222 static int srp_create_target_ib(struct srp_target_port *target)
223 {
224 	struct ib_qp_init_attr *init_attr;
225 	int ret;
226 
227 	init_attr = kzalloc(sizeof *init_attr, GFP_KERNEL);
228 	if (!init_attr)
229 		return -ENOMEM;
230 
231 	target->recv_cq = ib_create_cq(target->srp_host->srp_dev->dev,
232 				       srp_recv_completion, NULL, target, SRP_RQ_SIZE, 0);
233 	if (IS_ERR(target->recv_cq)) {
234 		ret = PTR_ERR(target->recv_cq);
235 		goto err;
236 	}
237 
238 	target->send_cq = ib_create_cq(target->srp_host->srp_dev->dev,
239 				       srp_send_completion, NULL, target, SRP_SQ_SIZE, 0);
240 	if (IS_ERR(target->send_cq)) {
241 		ret = PTR_ERR(target->send_cq);
242 		goto err_recv_cq;
243 	}
244 
245 	ib_req_notify_cq(target->recv_cq, IB_CQ_NEXT_COMP);
246 
247 	init_attr->event_handler       = srp_qp_event;
248 	init_attr->cap.max_send_wr     = SRP_SQ_SIZE;
249 	init_attr->cap.max_recv_wr     = SRP_RQ_SIZE;
250 	init_attr->cap.max_recv_sge    = 1;
251 	init_attr->cap.max_send_sge    = 1;
252 	init_attr->sq_sig_type         = IB_SIGNAL_ALL_WR;
253 	init_attr->qp_type             = IB_QPT_RC;
254 	init_attr->send_cq             = target->send_cq;
255 	init_attr->recv_cq             = target->recv_cq;
256 
257 	target->qp = ib_create_qp(target->srp_host->srp_dev->pd, init_attr);
258 	if (IS_ERR(target->qp)) {
259 		ret = PTR_ERR(target->qp);
260 		goto err_send_cq;
261 	}
262 
263 	ret = srp_init_qp(target, target->qp);
264 	if (ret)
265 		goto err_qp;
266 
267 	kfree(init_attr);
268 	return 0;
269 
270 err_qp:
271 	ib_destroy_qp(target->qp);
272 
273 err_send_cq:
274 	ib_destroy_cq(target->send_cq);
275 
276 err_recv_cq:
277 	ib_destroy_cq(target->recv_cq);
278 
279 err:
280 	kfree(init_attr);
281 	return ret;
282 }
283 
284 static void srp_free_target_ib(struct srp_target_port *target)
285 {
286 	int i;
287 
288 	ib_destroy_qp(target->qp);
289 	ib_destroy_cq(target->send_cq);
290 	ib_destroy_cq(target->recv_cq);
291 
292 	for (i = 0; i < SRP_RQ_SIZE; ++i)
293 		srp_free_iu(target->srp_host, target->rx_ring[i]);
294 	for (i = 0; i < SRP_SQ_SIZE; ++i)
295 		srp_free_iu(target->srp_host, target->tx_ring[i]);
296 }
297 
298 static void srp_path_rec_completion(int status,
299 				    struct ib_sa_path_rec *pathrec,
300 				    void *target_ptr)
301 {
302 	struct srp_target_port *target = target_ptr;
303 
304 	target->status = status;
305 	if (status)
306 		shost_printk(KERN_ERR, target->scsi_host,
307 			     PFX "Got failed path rec status %d\n", status);
308 	else
309 		target->path = *pathrec;
310 	complete(&target->done);
311 }
312 
313 static int srp_lookup_path(struct srp_target_port *target)
314 {
315 	target->path.numb_path = 1;
316 
317 	init_completion(&target->done);
318 
319 	target->path_query_id = ib_sa_path_rec_get(&srp_sa_client,
320 						   target->srp_host->srp_dev->dev,
321 						   target->srp_host->port,
322 						   &target->path,
323 						   IB_SA_PATH_REC_SERVICE_ID	|
324 						   IB_SA_PATH_REC_DGID		|
325 						   IB_SA_PATH_REC_SGID		|
326 						   IB_SA_PATH_REC_NUMB_PATH	|
327 						   IB_SA_PATH_REC_PKEY,
328 						   SRP_PATH_REC_TIMEOUT_MS,
329 						   GFP_KERNEL,
330 						   srp_path_rec_completion,
331 						   target, &target->path_query);
332 	if (target->path_query_id < 0)
333 		return target->path_query_id;
334 
335 	wait_for_completion(&target->done);
336 
337 	if (target->status < 0)
338 		shost_printk(KERN_WARNING, target->scsi_host,
339 			     PFX "Path record query failed\n");
340 
341 	return target->status;
342 }
343 
344 static int srp_send_req(struct srp_target_port *target)
345 {
346 	struct {
347 		struct ib_cm_req_param param;
348 		struct srp_login_req   priv;
349 	} *req = NULL;
350 	int status;
351 
352 	req = kzalloc(sizeof *req, GFP_KERNEL);
353 	if (!req)
354 		return -ENOMEM;
355 
356 	req->param.primary_path 	      = &target->path;
357 	req->param.alternate_path 	      = NULL;
358 	req->param.service_id 		      = target->service_id;
359 	req->param.qp_num 		      = target->qp->qp_num;
360 	req->param.qp_type 		      = target->qp->qp_type;
361 	req->param.private_data 	      = &req->priv;
362 	req->param.private_data_len 	      = sizeof req->priv;
363 	req->param.flow_control 	      = 1;
364 
365 	get_random_bytes(&req->param.starting_psn, 4);
366 	req->param.starting_psn 	     &= 0xffffff;
367 
368 	/*
369 	 * Pick some arbitrary defaults here; we could make these
370 	 * module parameters if anyone cared about setting them.
371 	 */
372 	req->param.responder_resources	      = 4;
373 	req->param.remote_cm_response_timeout = 20;
374 	req->param.local_cm_response_timeout  = 20;
375 	req->param.retry_count 		      = 7;
376 	req->param.rnr_retry_count 	      = 7;
377 	req->param.max_cm_retries 	      = 15;
378 
379 	req->priv.opcode     	= SRP_LOGIN_REQ;
380 	req->priv.tag        	= 0;
381 	req->priv.req_it_iu_len = cpu_to_be32(srp_max_iu_len);
382 	req->priv.req_buf_fmt 	= cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
383 					      SRP_BUF_FORMAT_INDIRECT);
384 	/*
385 	 * In the published SRP specification (draft rev. 16a), the
386 	 * port identifier format is 8 bytes of ID extension followed
387 	 * by 8 bytes of GUID.  Older drafts put the two halves in the
388 	 * opposite order, so that the GUID comes first.
389 	 *
390 	 * Targets conforming to these obsolete drafts can be
391 	 * recognized by the I/O Class they report.
392 	 */
393 	if (target->io_class == SRP_REV10_IB_IO_CLASS) {
394 		memcpy(req->priv.initiator_port_id,
395 		       &target->path.sgid.global.interface_id, 8);
396 		memcpy(req->priv.initiator_port_id + 8,
397 		       &target->initiator_ext, 8);
398 		memcpy(req->priv.target_port_id,     &target->ioc_guid, 8);
399 		memcpy(req->priv.target_port_id + 8, &target->id_ext, 8);
400 	} else {
401 		memcpy(req->priv.initiator_port_id,
402 		       &target->initiator_ext, 8);
403 		memcpy(req->priv.initiator_port_id + 8,
404 		       &target->path.sgid.global.interface_id, 8);
405 		memcpy(req->priv.target_port_id,     &target->id_ext, 8);
406 		memcpy(req->priv.target_port_id + 8, &target->ioc_guid, 8);
407 	}
408 
409 	/*
410 	 * Topspin/Cisco SRP targets will reject our login unless we
411 	 * zero out the first 8 bytes of our initiator port ID and set
412 	 * the second 8 bytes to the local node GUID.
413 	 */
414 	if (srp_target_is_topspin(target)) {
415 		shost_printk(KERN_DEBUG, target->scsi_host,
416 			     PFX "Topspin/Cisco initiator port ID workaround "
417 			     "activated for target GUID %016llx\n",
418 			     (unsigned long long) be64_to_cpu(target->ioc_guid));
419 		memset(req->priv.initiator_port_id, 0, 8);
420 		memcpy(req->priv.initiator_port_id + 8,
421 		       &target->srp_host->srp_dev->dev->node_guid, 8);
422 	}
423 
424 	status = ib_send_cm_req(target->cm_id, &req->param);
425 
426 	kfree(req);
427 
428 	return status;
429 }
430 
431 static void srp_disconnect_target(struct srp_target_port *target)
432 {
433 	/* XXX should send SRP_I_LOGOUT request */
434 
435 	init_completion(&target->done);
436 	if (ib_send_cm_dreq(target->cm_id, NULL, 0)) {
437 		shost_printk(KERN_DEBUG, target->scsi_host,
438 			     PFX "Sending CM DREQ failed\n");
439 		return;
440 	}
441 	wait_for_completion(&target->done);
442 }
443 
444 static void srp_remove_work(struct work_struct *work)
445 {
446 	struct srp_target_port *target =
447 		container_of(work, struct srp_target_port, work);
448 
449 	spin_lock_irq(target->scsi_host->host_lock);
450 	if (target->state != SRP_TARGET_DEAD) {
451 		spin_unlock_irq(target->scsi_host->host_lock);
452 		return;
453 	}
454 	target->state = SRP_TARGET_REMOVED;
455 	spin_unlock_irq(target->scsi_host->host_lock);
456 
457 	spin_lock(&target->srp_host->target_lock);
458 	list_del(&target->list);
459 	spin_unlock(&target->srp_host->target_lock);
460 
461 	srp_remove_host(target->scsi_host);
462 	scsi_remove_host(target->scsi_host);
463 	ib_destroy_cm_id(target->cm_id);
464 	srp_free_target_ib(target);
465 	scsi_host_put(target->scsi_host);
466 }
467 
468 static int srp_connect_target(struct srp_target_port *target)
469 {
470 	int retries = 3;
471 	int ret;
472 
473 	ret = srp_lookup_path(target);
474 	if (ret)
475 		return ret;
476 
477 	while (1) {
478 		init_completion(&target->done);
479 		ret = srp_send_req(target);
480 		if (ret)
481 			return ret;
482 		wait_for_completion(&target->done);
483 
484 		/*
485 		 * The CM event handling code will set status to
486 		 * SRP_PORT_REDIRECT if we get a port redirect REJ
487 		 * back, or SRP_DLID_REDIRECT if we get a lid/qp
488 		 * redirect REJ back.
489 		 */
490 		switch (target->status) {
491 		case 0:
492 			return 0;
493 
494 		case SRP_PORT_REDIRECT:
495 			ret = srp_lookup_path(target);
496 			if (ret)
497 				return ret;
498 			break;
499 
500 		case SRP_DLID_REDIRECT:
501 			break;
502 
503 		case SRP_STALE_CONN:
504 			/* Our current CM id was stale, and is now in timewait.
505 			 * Try to reconnect with a new one.
506 			 */
507 			if (!retries-- || srp_new_cm_id(target)) {
508 				shost_printk(KERN_ERR, target->scsi_host, PFX
509 					     "giving up on stale connection\n");
510 				target->status = -ECONNRESET;
511 				return target->status;
512 			}
513 
514 			shost_printk(KERN_ERR, target->scsi_host, PFX
515 				     "retrying stale connection\n");
516 			break;
517 
518 		default:
519 			return target->status;
520 		}
521 	}
522 }
523 
524 static void srp_unmap_data(struct scsi_cmnd *scmnd,
525 			   struct srp_target_port *target,
526 			   struct srp_request *req)
527 {
528 	if (!scsi_sglist(scmnd) ||
529 	    (scmnd->sc_data_direction != DMA_TO_DEVICE &&
530 	     scmnd->sc_data_direction != DMA_FROM_DEVICE))
531 		return;
532 
533 	if (req->fmr) {
534 		ib_fmr_pool_unmap(req->fmr);
535 		req->fmr = NULL;
536 	}
537 
538 	ib_dma_unmap_sg(target->srp_host->srp_dev->dev, scsi_sglist(scmnd),
539 			scsi_sg_count(scmnd), scmnd->sc_data_direction);
540 }
541 
542 static void srp_remove_req(struct srp_target_port *target, struct srp_request *req)
543 {
544 	srp_unmap_data(req->scmnd, target, req);
545 	list_move_tail(&req->list, &target->free_reqs);
546 }
547 
548 static void srp_reset_req(struct srp_target_port *target, struct srp_request *req)
549 {
550 	req->scmnd->result = DID_RESET << 16;
551 	req->scmnd->scsi_done(req->scmnd);
552 	srp_remove_req(target, req);
553 }
554 
555 static int srp_reconnect_target(struct srp_target_port *target)
556 {
557 	struct ib_qp_attr qp_attr;
558 	struct srp_request *req, *tmp;
559 	struct ib_wc wc;
560 	int ret;
561 
562 	spin_lock_irq(target->scsi_host->host_lock);
563 	if (target->state != SRP_TARGET_LIVE) {
564 		spin_unlock_irq(target->scsi_host->host_lock);
565 		return -EAGAIN;
566 	}
567 	target->state = SRP_TARGET_CONNECTING;
568 	spin_unlock_irq(target->scsi_host->host_lock);
569 
570 	srp_disconnect_target(target);
571 	/*
572 	 * Now get a new local CM ID so that we avoid confusing the
573 	 * target in case things are really fouled up.
574 	 */
575 	ret = srp_new_cm_id(target);
576 	if (ret)
577 		goto err;
578 
579 	qp_attr.qp_state = IB_QPS_RESET;
580 	ret = ib_modify_qp(target->qp, &qp_attr, IB_QP_STATE);
581 	if (ret)
582 		goto err;
583 
584 	ret = srp_init_qp(target, target->qp);
585 	if (ret)
586 		goto err;
587 
588 	while (ib_poll_cq(target->recv_cq, 1, &wc) > 0)
589 		; /* nothing */
590 	while (ib_poll_cq(target->send_cq, 1, &wc) > 0)
591 		; /* nothing */
592 
593 	spin_lock_irq(target->scsi_host->host_lock);
594 	list_for_each_entry_safe(req, tmp, &target->req_queue, list)
595 		srp_reset_req(target, req);
596 	spin_unlock_irq(target->scsi_host->host_lock);
597 
598 	target->rx_head	 = 0;
599 	target->tx_head	 = 0;
600 	target->tx_tail  = 0;
601 
602 	target->qp_in_error = 0;
603 	ret = srp_connect_target(target);
604 	if (ret)
605 		goto err;
606 
607 	spin_lock_irq(target->scsi_host->host_lock);
608 	if (target->state == SRP_TARGET_CONNECTING) {
609 		ret = 0;
610 		target->state = SRP_TARGET_LIVE;
611 	} else
612 		ret = -EAGAIN;
613 	spin_unlock_irq(target->scsi_host->host_lock);
614 
615 	return ret;
616 
617 err:
618 	shost_printk(KERN_ERR, target->scsi_host,
619 		     PFX "reconnect failed (%d), removing target port.\n", ret);
620 
621 	/*
622 	 * We couldn't reconnect, so kill our target port off.
623 	 * However, we have to defer the real removal because we might
624 	 * be in the context of the SCSI error handler now, which
625 	 * would deadlock if we call scsi_remove_host().
626 	 */
627 	spin_lock_irq(target->scsi_host->host_lock);
628 	if (target->state == SRP_TARGET_CONNECTING) {
629 		target->state = SRP_TARGET_DEAD;
630 		INIT_WORK(&target->work, srp_remove_work);
631 		schedule_work(&target->work);
632 	}
633 	spin_unlock_irq(target->scsi_host->host_lock);
634 
635 	return ret;
636 }
637 
638 static int srp_map_fmr(struct srp_target_port *target, struct scatterlist *scat,
639 		       int sg_cnt, struct srp_request *req,
640 		       struct srp_direct_buf *buf)
641 {
642 	u64 io_addr = 0;
643 	u64 *dma_pages;
644 	u32 len;
645 	int page_cnt;
646 	int i, j;
647 	int ret;
648 	struct srp_device *dev = target->srp_host->srp_dev;
649 	struct ib_device *ibdev = dev->dev;
650 	struct scatterlist *sg;
651 
652 	if (!dev->fmr_pool)
653 		return -ENODEV;
654 
655 	if (srp_target_is_mellanox(target) &&
656 	    (ib_sg_dma_address(ibdev, &scat[0]) & ~dev->fmr_page_mask))
657 		return -EINVAL;
658 
659 	len = page_cnt = 0;
660 	scsi_for_each_sg(req->scmnd, sg, sg_cnt, i) {
661 		unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
662 
663 		if (ib_sg_dma_address(ibdev, sg) & ~dev->fmr_page_mask) {
664 			if (i > 0)
665 				return -EINVAL;
666 			else
667 				++page_cnt;
668 		}
669 		if ((ib_sg_dma_address(ibdev, sg) + dma_len) &
670 		    ~dev->fmr_page_mask) {
671 			if (i < sg_cnt - 1)
672 				return -EINVAL;
673 			else
674 				++page_cnt;
675 		}
676 
677 		len += dma_len;
678 	}
679 
680 	page_cnt += len >> dev->fmr_page_shift;
681 	if (page_cnt > SRP_FMR_SIZE)
682 		return -ENOMEM;
683 
684 	dma_pages = kmalloc(sizeof (u64) * page_cnt, GFP_ATOMIC);
685 	if (!dma_pages)
686 		return -ENOMEM;
687 
688 	page_cnt = 0;
689 	scsi_for_each_sg(req->scmnd, sg, sg_cnt, i) {
690 		unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
691 
692 		for (j = 0; j < dma_len; j += dev->fmr_page_size)
693 			dma_pages[page_cnt++] =
694 				(ib_sg_dma_address(ibdev, sg) &
695 				 dev->fmr_page_mask) + j;
696 	}
697 
698 	req->fmr = ib_fmr_pool_map_phys(dev->fmr_pool,
699 					dma_pages, page_cnt, io_addr);
700 	if (IS_ERR(req->fmr)) {
701 		ret = PTR_ERR(req->fmr);
702 		req->fmr = NULL;
703 		goto out;
704 	}
705 
706 	buf->va  = cpu_to_be64(ib_sg_dma_address(ibdev, &scat[0]) &
707 			       ~dev->fmr_page_mask);
708 	buf->key = cpu_to_be32(req->fmr->fmr->rkey);
709 	buf->len = cpu_to_be32(len);
710 
711 	ret = 0;
712 
713 out:
714 	kfree(dma_pages);
715 
716 	return ret;
717 }
718 
719 static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
720 			struct srp_request *req)
721 {
722 	struct scatterlist *scat;
723 	struct srp_cmd *cmd = req->cmd->buf;
724 	int len, nents, count;
725 	u8 fmt = SRP_DATA_DESC_DIRECT;
726 	struct srp_device *dev;
727 	struct ib_device *ibdev;
728 
729 	if (!scsi_sglist(scmnd) || scmnd->sc_data_direction == DMA_NONE)
730 		return sizeof (struct srp_cmd);
731 
732 	if (scmnd->sc_data_direction != DMA_FROM_DEVICE &&
733 	    scmnd->sc_data_direction != DMA_TO_DEVICE) {
734 		shost_printk(KERN_WARNING, target->scsi_host,
735 			     PFX "Unhandled data direction %d\n",
736 			     scmnd->sc_data_direction);
737 		return -EINVAL;
738 	}
739 
740 	nents = scsi_sg_count(scmnd);
741 	scat  = scsi_sglist(scmnd);
742 
743 	dev = target->srp_host->srp_dev;
744 	ibdev = dev->dev;
745 
746 	count = ib_dma_map_sg(ibdev, scat, nents, scmnd->sc_data_direction);
747 
748 	fmt = SRP_DATA_DESC_DIRECT;
749 	len = sizeof (struct srp_cmd) +	sizeof (struct srp_direct_buf);
750 
751 	if (count == 1) {
752 		/*
753 		 * The midlayer only generated a single gather/scatter
754 		 * entry, or DMA mapping coalesced everything to a
755 		 * single entry.  So a direct descriptor along with
756 		 * the DMA MR suffices.
757 		 */
758 		struct srp_direct_buf *buf = (void *) cmd->add_data;
759 
760 		buf->va  = cpu_to_be64(ib_sg_dma_address(ibdev, scat));
761 		buf->key = cpu_to_be32(dev->mr->rkey);
762 		buf->len = cpu_to_be32(ib_sg_dma_len(ibdev, scat));
763 	} else if (srp_map_fmr(target, scat, count, req,
764 			       (void *) cmd->add_data)) {
765 		/*
766 		 * FMR mapping failed, and the scatterlist has more
767 		 * than one entry.  Generate an indirect memory
768 		 * descriptor.
769 		 */
770 		struct srp_indirect_buf *buf = (void *) cmd->add_data;
771 		struct scatterlist *sg;
772 		u32 datalen = 0;
773 		int i;
774 
775 		fmt = SRP_DATA_DESC_INDIRECT;
776 		len = sizeof (struct srp_cmd) +
777 			sizeof (struct srp_indirect_buf) +
778 			count * sizeof (struct srp_direct_buf);
779 
780 		scsi_for_each_sg(scmnd, sg, count, i) {
781 			unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
782 
783 			buf->desc_list[i].va  =
784 				cpu_to_be64(ib_sg_dma_address(ibdev, sg));
785 			buf->desc_list[i].key =
786 				cpu_to_be32(dev->mr->rkey);
787 			buf->desc_list[i].len = cpu_to_be32(dma_len);
788 			datalen += dma_len;
789 		}
790 
791 		if (scmnd->sc_data_direction == DMA_TO_DEVICE)
792 			cmd->data_out_desc_cnt = count;
793 		else
794 			cmd->data_in_desc_cnt = count;
795 
796 		buf->table_desc.va  =
797 			cpu_to_be64(req->cmd->dma + sizeof *cmd + sizeof *buf);
798 		buf->table_desc.key =
799 			cpu_to_be32(target->srp_host->srp_dev->mr->rkey);
800 		buf->table_desc.len =
801 			cpu_to_be32(count * sizeof (struct srp_direct_buf));
802 
803 		buf->len = cpu_to_be32(datalen);
804 	}
805 
806 	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
807 		cmd->buf_fmt = fmt << 4;
808 	else
809 		cmd->buf_fmt = fmt;
810 
811 	return len;
812 }
813 
814 /*
815  * Must be called with target->scsi_host->host_lock held to protect
816  * req_lim and tx_head.  Lock cannot be dropped between call here and
817  * call to __srp_post_send().
818  *
819  * Note:
820  * An upper limit for the number of allocated information units for each
821  * request type is:
822  * - SRP_IU_CMD: SRP_CMD_SQ_SIZE, since the SCSI mid-layer never queues
823  *   more than Scsi_Host.can_queue requests.
824  * - SRP_IU_TSK_MGMT: SRP_TSK_MGMT_SQ_SIZE.
825  * - SRP_IU_RSP: 1, since a conforming SRP target never sends more than
826  *   one unanswered SRP request to an initiator.
827  */
828 static struct srp_iu *__srp_get_tx_iu(struct srp_target_port *target,
829 				      enum srp_iu_type iu_type)
830 {
831 	s32 rsv = (iu_type == SRP_IU_TSK_MGMT) ? 0 : SRP_TSK_MGMT_SQ_SIZE;
832 	struct srp_iu *iu;
833 
834 	srp_send_completion(target->send_cq, target);
835 
836 	if (target->tx_head - target->tx_tail >= SRP_SQ_SIZE)
837 		return NULL;
838 
839 	/* Initiator responses to target requests do not consume credits */
840 	if (target->req_lim <= rsv && iu_type != SRP_IU_RSP) {
841 		++target->zero_req_lim;
842 		return NULL;
843 	}
844 
845 	iu = target->tx_ring[target->tx_head & SRP_SQ_MASK];
846 	iu->type = iu_type;
847 	return iu;
848 }
849 
850 /*
851  * Must be called with target->scsi_host->host_lock held to protect
852  * req_lim and tx_head.
853  */
854 static int __srp_post_send(struct srp_target_port *target,
855 			   struct srp_iu *iu, int len)
856 {
857 	struct ib_sge list;
858 	struct ib_send_wr wr, *bad_wr;
859 	int ret = 0;
860 
861 	list.addr   = iu->dma;
862 	list.length = len;
863 	list.lkey   = target->srp_host->srp_dev->mr->lkey;
864 
865 	wr.next       = NULL;
866 	wr.wr_id      = target->tx_head & SRP_SQ_MASK;
867 	wr.sg_list    = &list;
868 	wr.num_sge    = 1;
869 	wr.opcode     = IB_WR_SEND;
870 	wr.send_flags = IB_SEND_SIGNALED;
871 
872 	ret = ib_post_send(target->qp, &wr, &bad_wr);
873 
874 	if (!ret) {
875 		++target->tx_head;
876 		if (iu->type != SRP_IU_RSP)
877 			--target->req_lim;
878 	}
879 
880 	return ret;
881 }
882 
883 static int srp_post_recv(struct srp_target_port *target)
884 {
885 	unsigned long flags;
886 	struct srp_iu *iu;
887 	struct ib_sge list;
888 	struct ib_recv_wr wr, *bad_wr;
889 	unsigned int next;
890 	int ret;
891 
892 	spin_lock_irqsave(target->scsi_host->host_lock, flags);
893 
894 	next	 = target->rx_head & SRP_RQ_MASK;
895 	wr.wr_id = next;
896 	iu	 = target->rx_ring[next];
897 
898 	list.addr   = iu->dma;
899 	list.length = iu->size;
900 	list.lkey   = target->srp_host->srp_dev->mr->lkey;
901 
902 	wr.next     = NULL;
903 	wr.sg_list  = &list;
904 	wr.num_sge  = 1;
905 
906 	ret = ib_post_recv(target->qp, &wr, &bad_wr);
907 	if (!ret)
908 		++target->rx_head;
909 
910 	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
911 
912 	return ret;
913 }
914 
915 static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
916 {
917 	struct srp_request *req;
918 	struct scsi_cmnd *scmnd;
919 	unsigned long flags;
920 	s32 delta;
921 
922 	delta = (s32) be32_to_cpu(rsp->req_lim_delta);
923 
924 	spin_lock_irqsave(target->scsi_host->host_lock, flags);
925 
926 	target->req_lim += delta;
927 
928 	req = &target->req_ring[rsp->tag & ~SRP_TAG_TSK_MGMT];
929 
930 	if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
931 		if (be32_to_cpu(rsp->resp_data_len) < 4)
932 			req->tsk_status = -1;
933 		else
934 			req->tsk_status = rsp->data[3];
935 		complete(&req->done);
936 	} else {
937 		scmnd = req->scmnd;
938 		if (!scmnd)
939 			shost_printk(KERN_ERR, target->scsi_host,
940 				     "Null scmnd for RSP w/tag %016llx\n",
941 				     (unsigned long long) rsp->tag);
942 		scmnd->result = rsp->status;
943 
944 		if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
945 			memcpy(scmnd->sense_buffer, rsp->data +
946 			       be32_to_cpu(rsp->resp_data_len),
947 			       min_t(int, be32_to_cpu(rsp->sense_data_len),
948 				     SCSI_SENSE_BUFFERSIZE));
949 		}
950 
951 		if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
952 			scsi_set_resid(scmnd, be32_to_cpu(rsp->data_out_res_cnt));
953 		else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
954 			scsi_set_resid(scmnd, be32_to_cpu(rsp->data_in_res_cnt));
955 
956 		if (!req->tsk_mgmt) {
957 			scmnd->host_scribble = (void *) -1L;
958 			scmnd->scsi_done(scmnd);
959 
960 			srp_remove_req(target, req);
961 		} else
962 			req->cmd_done = 1;
963 	}
964 
965 	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
966 }
967 
968 static int srp_response_common(struct srp_target_port *target, s32 req_delta,
969 			       void *rsp, int len)
970 {
971 	struct ib_device *dev;
972 	unsigned long flags;
973 	struct srp_iu *iu;
974 	int err = 1;
975 
976 	dev = target->srp_host->srp_dev->dev;
977 
978 	spin_lock_irqsave(target->scsi_host->host_lock, flags);
979 	target->req_lim += req_delta;
980 
981 	iu = __srp_get_tx_iu(target, SRP_IU_RSP);
982 	if (!iu) {
983 		shost_printk(KERN_ERR, target->scsi_host, PFX
984 			     "no IU available to send response\n");
985 		goto out;
986 	}
987 
988 	ib_dma_sync_single_for_cpu(dev, iu->dma, len, DMA_TO_DEVICE);
989 	memcpy(iu->buf, rsp, len);
990 	ib_dma_sync_single_for_device(dev, iu->dma, len, DMA_TO_DEVICE);
991 
992 	err = __srp_post_send(target, iu, len);
993 	if (err)
994 		shost_printk(KERN_ERR, target->scsi_host, PFX
995 			     "unable to post response: %d\n", err);
996 
997 out:
998 	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
999 	return err;
1000 }
1001 
1002 static void srp_process_cred_req(struct srp_target_port *target,
1003 				 struct srp_cred_req *req)
1004 {
1005 	struct srp_cred_rsp rsp = {
1006 		.opcode = SRP_CRED_RSP,
1007 		.tag = req->tag,
1008 	};
1009 	s32 delta = be32_to_cpu(req->req_lim_delta);
1010 
1011 	if (srp_response_common(target, delta, &rsp, sizeof rsp))
1012 		shost_printk(KERN_ERR, target->scsi_host, PFX
1013 			     "problems processing SRP_CRED_REQ\n");
1014 }
1015 
1016 static void srp_process_aer_req(struct srp_target_port *target,
1017 				struct srp_aer_req *req)
1018 {
1019 	struct srp_aer_rsp rsp = {
1020 		.opcode = SRP_AER_RSP,
1021 		.tag = req->tag,
1022 	};
1023 	s32 delta = be32_to_cpu(req->req_lim_delta);
1024 
1025 	shost_printk(KERN_ERR, target->scsi_host, PFX
1026 		     "ignoring AER for LUN %llu\n", be64_to_cpu(req->lun));
1027 
1028 	if (srp_response_common(target, delta, &rsp, sizeof rsp))
1029 		shost_printk(KERN_ERR, target->scsi_host, PFX
1030 			     "problems processing SRP_AER_REQ\n");
1031 }
1032 
1033 static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
1034 {
1035 	struct ib_device *dev;
1036 	struct srp_iu *iu;
1037 	int res;
1038 	u8 opcode;
1039 
1040 	iu = target->rx_ring[wc->wr_id];
1041 
1042 	dev = target->srp_host->srp_dev->dev;
1043 	ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_ti_iu_len,
1044 				   DMA_FROM_DEVICE);
1045 
1046 	opcode = *(u8 *) iu->buf;
1047 
1048 	if (0) {
1049 		shost_printk(KERN_ERR, target->scsi_host,
1050 			     PFX "recv completion, opcode 0x%02x\n", opcode);
1051 		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 8, 1,
1052 			       iu->buf, wc->byte_len, true);
1053 	}
1054 
1055 	switch (opcode) {
1056 	case SRP_RSP:
1057 		srp_process_rsp(target, iu->buf);
1058 		break;
1059 
1060 	case SRP_CRED_REQ:
1061 		srp_process_cred_req(target, iu->buf);
1062 		break;
1063 
1064 	case SRP_AER_REQ:
1065 		srp_process_aer_req(target, iu->buf);
1066 		break;
1067 
1068 	case SRP_T_LOGOUT:
1069 		/* XXX Handle target logout */
1070 		shost_printk(KERN_WARNING, target->scsi_host,
1071 			     PFX "Got target logout request\n");
1072 		break;
1073 
1074 	default:
1075 		shost_printk(KERN_WARNING, target->scsi_host,
1076 			     PFX "Unhandled SRP opcode 0x%02x\n", opcode);
1077 		break;
1078 	}
1079 
1080 	ib_dma_sync_single_for_device(dev, iu->dma, target->max_ti_iu_len,
1081 				      DMA_FROM_DEVICE);
1082 
1083 	res = srp_post_recv(target);
1084 	if (res != 0)
1085 		shost_printk(KERN_ERR, target->scsi_host,
1086 			     PFX "Recv failed with error code %d\n", res);
1087 }
1088 
1089 static void srp_recv_completion(struct ib_cq *cq, void *target_ptr)
1090 {
1091 	struct srp_target_port *target = target_ptr;
1092 	struct ib_wc wc;
1093 
1094 	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1095 	while (ib_poll_cq(cq, 1, &wc) > 0) {
1096 		if (wc.status) {
1097 			shost_printk(KERN_ERR, target->scsi_host,
1098 				     PFX "failed receive status %d\n",
1099 				     wc.status);
1100 			target->qp_in_error = 1;
1101 			break;
1102 		}
1103 
1104 		srp_handle_recv(target, &wc);
1105 	}
1106 }
1107 
1108 static void srp_send_completion(struct ib_cq *cq, void *target_ptr)
1109 {
1110 	struct srp_target_port *target = target_ptr;
1111 	struct ib_wc wc;
1112 
1113 	while (ib_poll_cq(cq, 1, &wc) > 0) {
1114 		if (wc.status) {
1115 			shost_printk(KERN_ERR, target->scsi_host,
1116 				     PFX "failed send status %d\n",
1117 				     wc.status);
1118 			target->qp_in_error = 1;
1119 			break;
1120 		}
1121 
1122 		++target->tx_tail;
1123 	}
1124 }
1125 
1126 static int srp_queuecommand_lck(struct scsi_cmnd *scmnd,
1127 			    void (*done)(struct scsi_cmnd *))
1128 {
1129 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1130 	struct srp_request *req;
1131 	struct srp_iu *iu;
1132 	struct srp_cmd *cmd;
1133 	struct ib_device *dev;
1134 	int len;
1135 
1136 	if (target->state == SRP_TARGET_CONNECTING)
1137 		goto err;
1138 
1139 	if (target->state == SRP_TARGET_DEAD ||
1140 	    target->state == SRP_TARGET_REMOVED) {
1141 		scmnd->result = DID_BAD_TARGET << 16;
1142 		done(scmnd);
1143 		return 0;
1144 	}
1145 
1146 	iu = __srp_get_tx_iu(target, SRP_IU_CMD);
1147 	if (!iu)
1148 		goto err;
1149 
1150 	dev = target->srp_host->srp_dev->dev;
1151 	ib_dma_sync_single_for_cpu(dev, iu->dma, srp_max_iu_len,
1152 				   DMA_TO_DEVICE);
1153 
1154 	req = list_first_entry(&target->free_reqs, struct srp_request, list);
1155 
1156 	scmnd->scsi_done     = done;
1157 	scmnd->result        = 0;
1158 	scmnd->host_scribble = (void *) (long) req->index;
1159 
1160 	cmd = iu->buf;
1161 	memset(cmd, 0, sizeof *cmd);
1162 
1163 	cmd->opcode = SRP_CMD;
1164 	cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
1165 	cmd->tag    = req->index;
1166 	memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
1167 
1168 	req->scmnd    = scmnd;
1169 	req->cmd      = iu;
1170 	req->cmd_done = 0;
1171 	req->tsk_mgmt = NULL;
1172 
1173 	len = srp_map_data(scmnd, target, req);
1174 	if (len < 0) {
1175 		shost_printk(KERN_ERR, target->scsi_host,
1176 			     PFX "Failed to map data\n");
1177 		goto err;
1178 	}
1179 
1180 	ib_dma_sync_single_for_device(dev, iu->dma, srp_max_iu_len,
1181 				      DMA_TO_DEVICE);
1182 
1183 	if (__srp_post_send(target, iu, len)) {
1184 		shost_printk(KERN_ERR, target->scsi_host, PFX "Send failed\n");
1185 		goto err_unmap;
1186 	}
1187 
1188 	list_move_tail(&req->list, &target->req_queue);
1189 
1190 	return 0;
1191 
1192 err_unmap:
1193 	srp_unmap_data(scmnd, target, req);
1194 
1195 err:
1196 	return SCSI_MLQUEUE_HOST_BUSY;
1197 }
1198 
1199 static DEF_SCSI_QCMD(srp_queuecommand)
1200 
1201 static int srp_alloc_iu_bufs(struct srp_target_port *target)
1202 {
1203 	int i;
1204 
1205 	for (i = 0; i < SRP_RQ_SIZE; ++i) {
1206 		target->rx_ring[i] = srp_alloc_iu(target->srp_host,
1207 						  target->max_ti_iu_len,
1208 						  GFP_KERNEL, DMA_FROM_DEVICE);
1209 		if (!target->rx_ring[i])
1210 			goto err;
1211 	}
1212 
1213 	for (i = 0; i < SRP_SQ_SIZE; ++i) {
1214 		target->tx_ring[i] = srp_alloc_iu(target->srp_host,
1215 						  srp_max_iu_len,
1216 						  GFP_KERNEL, DMA_TO_DEVICE);
1217 		if (!target->tx_ring[i])
1218 			goto err;
1219 	}
1220 
1221 	return 0;
1222 
1223 err:
1224 	for (i = 0; i < SRP_RQ_SIZE; ++i) {
1225 		srp_free_iu(target->srp_host, target->rx_ring[i]);
1226 		target->rx_ring[i] = NULL;
1227 	}
1228 
1229 	for (i = 0; i < SRP_SQ_SIZE; ++i) {
1230 		srp_free_iu(target->srp_host, target->tx_ring[i]);
1231 		target->tx_ring[i] = NULL;
1232 	}
1233 
1234 	return -ENOMEM;
1235 }
1236 
1237 static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
1238 			       struct ib_cm_event *event,
1239 			       struct srp_target_port *target)
1240 {
1241 	struct Scsi_Host *shost = target->scsi_host;
1242 	struct ib_class_port_info *cpi;
1243 	int opcode;
1244 
1245 	switch (event->param.rej_rcvd.reason) {
1246 	case IB_CM_REJ_PORT_CM_REDIRECT:
1247 		cpi = event->param.rej_rcvd.ari;
1248 		target->path.dlid = cpi->redirect_lid;
1249 		target->path.pkey = cpi->redirect_pkey;
1250 		cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
1251 		memcpy(target->path.dgid.raw, cpi->redirect_gid, 16);
1252 
1253 		target->status = target->path.dlid ?
1254 			SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
1255 		break;
1256 
1257 	case IB_CM_REJ_PORT_REDIRECT:
1258 		if (srp_target_is_topspin(target)) {
1259 			/*
1260 			 * Topspin/Cisco SRP gateways incorrectly send
1261 			 * reject reason code 25 when they mean 24
1262 			 * (port redirect).
1263 			 */
1264 			memcpy(target->path.dgid.raw,
1265 			       event->param.rej_rcvd.ari, 16);
1266 
1267 			shost_printk(KERN_DEBUG, shost,
1268 				     PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
1269 				     (unsigned long long) be64_to_cpu(target->path.dgid.global.subnet_prefix),
1270 				     (unsigned long long) be64_to_cpu(target->path.dgid.global.interface_id));
1271 
1272 			target->status = SRP_PORT_REDIRECT;
1273 		} else {
1274 			shost_printk(KERN_WARNING, shost,
1275 				     "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
1276 			target->status = -ECONNRESET;
1277 		}
1278 		break;
1279 
1280 	case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
1281 		shost_printk(KERN_WARNING, shost,
1282 			    "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
1283 		target->status = -ECONNRESET;
1284 		break;
1285 
1286 	case IB_CM_REJ_CONSUMER_DEFINED:
1287 		opcode = *(u8 *) event->private_data;
1288 		if (opcode == SRP_LOGIN_REJ) {
1289 			struct srp_login_rej *rej = event->private_data;
1290 			u32 reason = be32_to_cpu(rej->reason);
1291 
1292 			if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
1293 				shost_printk(KERN_WARNING, shost,
1294 					     PFX "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
1295 			else
1296 				shost_printk(KERN_WARNING, shost,
1297 					    PFX "SRP LOGIN REJECTED, reason 0x%08x\n", reason);
1298 		} else
1299 			shost_printk(KERN_WARNING, shost,
1300 				     "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
1301 				     " opcode 0x%02x\n", opcode);
1302 		target->status = -ECONNRESET;
1303 		break;
1304 
1305 	case IB_CM_REJ_STALE_CONN:
1306 		shost_printk(KERN_WARNING, shost, "  REJ reason: stale connection\n");
1307 		target->status = SRP_STALE_CONN;
1308 		break;
1309 
1310 	default:
1311 		shost_printk(KERN_WARNING, shost, "  REJ reason 0x%x\n",
1312 			     event->param.rej_rcvd.reason);
1313 		target->status = -ECONNRESET;
1314 	}
1315 }
1316 
1317 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
1318 {
1319 	struct srp_target_port *target = cm_id->context;
1320 	struct ib_qp_attr *qp_attr = NULL;
1321 	int attr_mask = 0;
1322 	int comp = 0;
1323 	int opcode = 0;
1324 	int i;
1325 
1326 	switch (event->event) {
1327 	case IB_CM_REQ_ERROR:
1328 		shost_printk(KERN_DEBUG, target->scsi_host,
1329 			     PFX "Sending CM REQ failed\n");
1330 		comp = 1;
1331 		target->status = -ECONNRESET;
1332 		break;
1333 
1334 	case IB_CM_REP_RECEIVED:
1335 		comp = 1;
1336 		opcode = *(u8 *) event->private_data;
1337 
1338 		if (opcode == SRP_LOGIN_RSP) {
1339 			struct srp_login_rsp *rsp = event->private_data;
1340 
1341 			target->max_ti_iu_len = be32_to_cpu(rsp->max_ti_iu_len);
1342 			target->req_lim       = be32_to_cpu(rsp->req_lim_delta);
1343 
1344 			/*
1345 			 * Reserve credits for task management so we don't
1346 			 * bounce requests back to the SCSI mid-layer.
1347 			 */
1348 			target->scsi_host->can_queue
1349 				= min(target->req_lim - SRP_TSK_MGMT_SQ_SIZE,
1350 				      target->scsi_host->can_queue);
1351 		} else {
1352 			shost_printk(KERN_WARNING, target->scsi_host,
1353 				    PFX "Unhandled RSP opcode %#x\n", opcode);
1354 			target->status = -ECONNRESET;
1355 			break;
1356 		}
1357 
1358 		if (!target->rx_ring[0]) {
1359 			target->status = srp_alloc_iu_bufs(target);
1360 			if (target->status)
1361 				break;
1362 		}
1363 
1364 		qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
1365 		if (!qp_attr) {
1366 			target->status = -ENOMEM;
1367 			break;
1368 		}
1369 
1370 		qp_attr->qp_state = IB_QPS_RTR;
1371 		target->status = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1372 		if (target->status)
1373 			break;
1374 
1375 		target->status = ib_modify_qp(target->qp, qp_attr, attr_mask);
1376 		if (target->status)
1377 			break;
1378 
1379 		for (i = 0; i < SRP_RQ_SIZE; i++) {
1380 			target->status = srp_post_recv(target);
1381 			if (target->status)
1382 				break;
1383 		}
1384 		if (target->status)
1385 			break;
1386 
1387 		qp_attr->qp_state = IB_QPS_RTS;
1388 		target->status = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1389 		if (target->status)
1390 			break;
1391 
1392 		target->status = ib_modify_qp(target->qp, qp_attr, attr_mask);
1393 		if (target->status)
1394 			break;
1395 
1396 		target->status = ib_send_cm_rtu(cm_id, NULL, 0);
1397 		if (target->status)
1398 			break;
1399 
1400 		break;
1401 
1402 	case IB_CM_REJ_RECEIVED:
1403 		shost_printk(KERN_DEBUG, target->scsi_host, PFX "REJ received\n");
1404 		comp = 1;
1405 
1406 		srp_cm_rej_handler(cm_id, event, target);
1407 		break;
1408 
1409 	case IB_CM_DREQ_RECEIVED:
1410 		shost_printk(KERN_WARNING, target->scsi_host,
1411 			     PFX "DREQ received - connection closed\n");
1412 		if (ib_send_cm_drep(cm_id, NULL, 0))
1413 			shost_printk(KERN_ERR, target->scsi_host,
1414 				     PFX "Sending CM DREP failed\n");
1415 		break;
1416 
1417 	case IB_CM_TIMEWAIT_EXIT:
1418 		shost_printk(KERN_ERR, target->scsi_host,
1419 			     PFX "connection closed\n");
1420 
1421 		comp = 1;
1422 		target->status = 0;
1423 		break;
1424 
1425 	case IB_CM_MRA_RECEIVED:
1426 	case IB_CM_DREQ_ERROR:
1427 	case IB_CM_DREP_RECEIVED:
1428 		break;
1429 
1430 	default:
1431 		shost_printk(KERN_WARNING, target->scsi_host,
1432 			     PFX "Unhandled CM event %d\n", event->event);
1433 		break;
1434 	}
1435 
1436 	if (comp)
1437 		complete(&target->done);
1438 
1439 	kfree(qp_attr);
1440 
1441 	return 0;
1442 }
1443 
1444 static int srp_send_tsk_mgmt(struct srp_target_port *target,
1445 			     struct srp_request *req, u8 func)
1446 {
1447 	struct ib_device *dev = target->srp_host->srp_dev->dev;
1448 	struct srp_iu *iu;
1449 	struct srp_tsk_mgmt *tsk_mgmt;
1450 
1451 	spin_lock_irq(target->scsi_host->host_lock);
1452 
1453 	if (target->state == SRP_TARGET_DEAD ||
1454 	    target->state == SRP_TARGET_REMOVED) {
1455 		req->scmnd->result = DID_BAD_TARGET << 16;
1456 		goto out;
1457 	}
1458 
1459 	init_completion(&req->done);
1460 
1461 	iu = __srp_get_tx_iu(target, SRP_IU_TSK_MGMT);
1462 	if (!iu)
1463 		goto out;
1464 
1465 	ib_dma_sync_single_for_cpu(dev, iu->dma, sizeof *tsk_mgmt,
1466 				   DMA_TO_DEVICE);
1467 	tsk_mgmt = iu->buf;
1468 	memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
1469 
1470 	tsk_mgmt->opcode 	= SRP_TSK_MGMT;
1471 	tsk_mgmt->lun 		= cpu_to_be64((u64) req->scmnd->device->lun << 48);
1472 	tsk_mgmt->tag 		= req->index | SRP_TAG_TSK_MGMT;
1473 	tsk_mgmt->tsk_mgmt_func = func;
1474 	tsk_mgmt->task_tag 	= req->index;
1475 
1476 	ib_dma_sync_single_for_device(dev, iu->dma, sizeof *tsk_mgmt,
1477 				      DMA_TO_DEVICE);
1478 	if (__srp_post_send(target, iu, sizeof *tsk_mgmt))
1479 		goto out;
1480 
1481 	req->tsk_mgmt = iu;
1482 
1483 	spin_unlock_irq(target->scsi_host->host_lock);
1484 
1485 	if (!wait_for_completion_timeout(&req->done,
1486 					 msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
1487 		return -1;
1488 
1489 	return 0;
1490 
1491 out:
1492 	spin_unlock_irq(target->scsi_host->host_lock);
1493 	return -1;
1494 }
1495 
1496 static int srp_find_req(struct srp_target_port *target,
1497 			struct scsi_cmnd *scmnd,
1498 			struct srp_request **req)
1499 {
1500 	if (scmnd->host_scribble == (void *) -1L)
1501 		return -1;
1502 
1503 	*req = &target->req_ring[(long) scmnd->host_scribble];
1504 
1505 	return 0;
1506 }
1507 
1508 static int srp_abort(struct scsi_cmnd *scmnd)
1509 {
1510 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1511 	struct srp_request *req;
1512 	int ret = SUCCESS;
1513 
1514 	shost_printk(KERN_ERR, target->scsi_host, "SRP abort called\n");
1515 
1516 	if (target->qp_in_error)
1517 		return FAILED;
1518 	if (srp_find_req(target, scmnd, &req))
1519 		return FAILED;
1520 	if (srp_send_tsk_mgmt(target, req, SRP_TSK_ABORT_TASK))
1521 		return FAILED;
1522 
1523 	spin_lock_irq(target->scsi_host->host_lock);
1524 
1525 	if (req->cmd_done) {
1526 		srp_remove_req(target, req);
1527 		scmnd->scsi_done(scmnd);
1528 	} else if (!req->tsk_status) {
1529 		srp_remove_req(target, req);
1530 		scmnd->result = DID_ABORT << 16;
1531 	} else
1532 		ret = FAILED;
1533 
1534 	spin_unlock_irq(target->scsi_host->host_lock);
1535 
1536 	return ret;
1537 }
1538 
1539 static int srp_reset_device(struct scsi_cmnd *scmnd)
1540 {
1541 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1542 	struct srp_request *req, *tmp;
1543 
1544 	shost_printk(KERN_ERR, target->scsi_host, "SRP reset_device called\n");
1545 
1546 	if (target->qp_in_error)
1547 		return FAILED;
1548 	if (srp_find_req(target, scmnd, &req))
1549 		return FAILED;
1550 	if (srp_send_tsk_mgmt(target, req, SRP_TSK_LUN_RESET))
1551 		return FAILED;
1552 	if (req->tsk_status)
1553 		return FAILED;
1554 
1555 	spin_lock_irq(target->scsi_host->host_lock);
1556 
1557 	list_for_each_entry_safe(req, tmp, &target->req_queue, list)
1558 		if (req->scmnd->device == scmnd->device)
1559 			srp_reset_req(target, req);
1560 
1561 	spin_unlock_irq(target->scsi_host->host_lock);
1562 
1563 	return SUCCESS;
1564 }
1565 
1566 static int srp_reset_host(struct scsi_cmnd *scmnd)
1567 {
1568 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1569 	int ret = FAILED;
1570 
1571 	shost_printk(KERN_ERR, target->scsi_host, PFX "SRP reset_host called\n");
1572 
1573 	if (!srp_reconnect_target(target))
1574 		ret = SUCCESS;
1575 
1576 	return ret;
1577 }
1578 
1579 static ssize_t show_id_ext(struct device *dev, struct device_attribute *attr,
1580 			   char *buf)
1581 {
1582 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1583 
1584 	if (target->state == SRP_TARGET_DEAD ||
1585 	    target->state == SRP_TARGET_REMOVED)
1586 		return -ENODEV;
1587 
1588 	return sprintf(buf, "0x%016llx\n",
1589 		       (unsigned long long) be64_to_cpu(target->id_ext));
1590 }
1591 
1592 static ssize_t show_ioc_guid(struct device *dev, struct device_attribute *attr,
1593 			     char *buf)
1594 {
1595 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1596 
1597 	if (target->state == SRP_TARGET_DEAD ||
1598 	    target->state == SRP_TARGET_REMOVED)
1599 		return -ENODEV;
1600 
1601 	return sprintf(buf, "0x%016llx\n",
1602 		       (unsigned long long) be64_to_cpu(target->ioc_guid));
1603 }
1604 
1605 static ssize_t show_service_id(struct device *dev,
1606 			       struct device_attribute *attr, char *buf)
1607 {
1608 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1609 
1610 	if (target->state == SRP_TARGET_DEAD ||
1611 	    target->state == SRP_TARGET_REMOVED)
1612 		return -ENODEV;
1613 
1614 	return sprintf(buf, "0x%016llx\n",
1615 		       (unsigned long long) be64_to_cpu(target->service_id));
1616 }
1617 
1618 static ssize_t show_pkey(struct device *dev, struct device_attribute *attr,
1619 			 char *buf)
1620 {
1621 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1622 
1623 	if (target->state == SRP_TARGET_DEAD ||
1624 	    target->state == SRP_TARGET_REMOVED)
1625 		return -ENODEV;
1626 
1627 	return sprintf(buf, "0x%04x\n", be16_to_cpu(target->path.pkey));
1628 }
1629 
1630 static ssize_t show_dgid(struct device *dev, struct device_attribute *attr,
1631 			 char *buf)
1632 {
1633 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1634 
1635 	if (target->state == SRP_TARGET_DEAD ||
1636 	    target->state == SRP_TARGET_REMOVED)
1637 		return -ENODEV;
1638 
1639 	return sprintf(buf, "%pI6\n", target->path.dgid.raw);
1640 }
1641 
1642 static ssize_t show_orig_dgid(struct device *dev,
1643 			      struct device_attribute *attr, char *buf)
1644 {
1645 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1646 
1647 	if (target->state == SRP_TARGET_DEAD ||
1648 	    target->state == SRP_TARGET_REMOVED)
1649 		return -ENODEV;
1650 
1651 	return sprintf(buf, "%pI6\n", target->orig_dgid);
1652 }
1653 
1654 static ssize_t show_req_lim(struct device *dev,
1655 			    struct device_attribute *attr, char *buf)
1656 {
1657 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1658 
1659 	if (target->state == SRP_TARGET_DEAD ||
1660 	    target->state == SRP_TARGET_REMOVED)
1661 		return -ENODEV;
1662 
1663 	return sprintf(buf, "%d\n", target->req_lim);
1664 }
1665 
1666 static ssize_t show_zero_req_lim(struct device *dev,
1667 				 struct device_attribute *attr, char *buf)
1668 {
1669 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1670 
1671 	if (target->state == SRP_TARGET_DEAD ||
1672 	    target->state == SRP_TARGET_REMOVED)
1673 		return -ENODEV;
1674 
1675 	return sprintf(buf, "%d\n", target->zero_req_lim);
1676 }
1677 
1678 static ssize_t show_local_ib_port(struct device *dev,
1679 				  struct device_attribute *attr, char *buf)
1680 {
1681 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1682 
1683 	return sprintf(buf, "%d\n", target->srp_host->port);
1684 }
1685 
1686 static ssize_t show_local_ib_device(struct device *dev,
1687 				    struct device_attribute *attr, char *buf)
1688 {
1689 	struct srp_target_port *target = host_to_target(class_to_shost(dev));
1690 
1691 	return sprintf(buf, "%s\n", target->srp_host->srp_dev->dev->name);
1692 }
1693 
1694 static DEVICE_ATTR(id_ext,	    S_IRUGO, show_id_ext,	   NULL);
1695 static DEVICE_ATTR(ioc_guid,	    S_IRUGO, show_ioc_guid,	   NULL);
1696 static DEVICE_ATTR(service_id,	    S_IRUGO, show_service_id,	   NULL);
1697 static DEVICE_ATTR(pkey,	    S_IRUGO, show_pkey,		   NULL);
1698 static DEVICE_ATTR(dgid,	    S_IRUGO, show_dgid,		   NULL);
1699 static DEVICE_ATTR(orig_dgid,	    S_IRUGO, show_orig_dgid,	   NULL);
1700 static DEVICE_ATTR(req_lim,         S_IRUGO, show_req_lim,         NULL);
1701 static DEVICE_ATTR(zero_req_lim,    S_IRUGO, show_zero_req_lim,	   NULL);
1702 static DEVICE_ATTR(local_ib_port,   S_IRUGO, show_local_ib_port,   NULL);
1703 static DEVICE_ATTR(local_ib_device, S_IRUGO, show_local_ib_device, NULL);
1704 
1705 static struct device_attribute *srp_host_attrs[] = {
1706 	&dev_attr_id_ext,
1707 	&dev_attr_ioc_guid,
1708 	&dev_attr_service_id,
1709 	&dev_attr_pkey,
1710 	&dev_attr_dgid,
1711 	&dev_attr_orig_dgid,
1712 	&dev_attr_req_lim,
1713 	&dev_attr_zero_req_lim,
1714 	&dev_attr_local_ib_port,
1715 	&dev_attr_local_ib_device,
1716 	NULL
1717 };
1718 
1719 static struct scsi_host_template srp_template = {
1720 	.module				= THIS_MODULE,
1721 	.name				= "InfiniBand SRP initiator",
1722 	.proc_name			= DRV_NAME,
1723 	.info				= srp_target_info,
1724 	.queuecommand			= srp_queuecommand,
1725 	.eh_abort_handler		= srp_abort,
1726 	.eh_device_reset_handler	= srp_reset_device,
1727 	.eh_host_reset_handler		= srp_reset_host,
1728 	.can_queue			= SRP_CMD_SQ_SIZE,
1729 	.this_id			= -1,
1730 	.cmd_per_lun			= SRP_CMD_SQ_SIZE,
1731 	.use_clustering			= ENABLE_CLUSTERING,
1732 	.shost_attrs			= srp_host_attrs
1733 };
1734 
1735 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
1736 {
1737 	struct srp_rport_identifiers ids;
1738 	struct srp_rport *rport;
1739 
1740 	sprintf(target->target_name, "SRP.T10:%016llX",
1741 		 (unsigned long long) be64_to_cpu(target->id_ext));
1742 
1743 	if (scsi_add_host(target->scsi_host, host->srp_dev->dev->dma_device))
1744 		return -ENODEV;
1745 
1746 	memcpy(ids.port_id, &target->id_ext, 8);
1747 	memcpy(ids.port_id + 8, &target->ioc_guid, 8);
1748 	ids.roles = SRP_RPORT_ROLE_TARGET;
1749 	rport = srp_rport_add(target->scsi_host, &ids);
1750 	if (IS_ERR(rport)) {
1751 		scsi_remove_host(target->scsi_host);
1752 		return PTR_ERR(rport);
1753 	}
1754 
1755 	spin_lock(&host->target_lock);
1756 	list_add_tail(&target->list, &host->target_list);
1757 	spin_unlock(&host->target_lock);
1758 
1759 	target->state = SRP_TARGET_LIVE;
1760 
1761 	scsi_scan_target(&target->scsi_host->shost_gendev,
1762 			 0, target->scsi_id, SCAN_WILD_CARD, 0);
1763 
1764 	return 0;
1765 }
1766 
1767 static void srp_release_dev(struct device *dev)
1768 {
1769 	struct srp_host *host =
1770 		container_of(dev, struct srp_host, dev);
1771 
1772 	complete(&host->released);
1773 }
1774 
1775 static struct class srp_class = {
1776 	.name    = "infiniband_srp",
1777 	.dev_release = srp_release_dev
1778 };
1779 
1780 /*
1781  * Target ports are added by writing
1782  *
1783  *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
1784  *     pkey=<P_Key>,service_id=<service ID>
1785  *
1786  * to the add_target sysfs attribute.
1787  */
1788 enum {
1789 	SRP_OPT_ERR		= 0,
1790 	SRP_OPT_ID_EXT		= 1 << 0,
1791 	SRP_OPT_IOC_GUID	= 1 << 1,
1792 	SRP_OPT_DGID		= 1 << 2,
1793 	SRP_OPT_PKEY		= 1 << 3,
1794 	SRP_OPT_SERVICE_ID	= 1 << 4,
1795 	SRP_OPT_MAX_SECT	= 1 << 5,
1796 	SRP_OPT_MAX_CMD_PER_LUN	= 1 << 6,
1797 	SRP_OPT_IO_CLASS	= 1 << 7,
1798 	SRP_OPT_INITIATOR_EXT	= 1 << 8,
1799 	SRP_OPT_ALL		= (SRP_OPT_ID_EXT	|
1800 				   SRP_OPT_IOC_GUID	|
1801 				   SRP_OPT_DGID		|
1802 				   SRP_OPT_PKEY		|
1803 				   SRP_OPT_SERVICE_ID),
1804 };
1805 
1806 static const match_table_t srp_opt_tokens = {
1807 	{ SRP_OPT_ID_EXT,		"id_ext=%s" 		},
1808 	{ SRP_OPT_IOC_GUID,		"ioc_guid=%s" 		},
1809 	{ SRP_OPT_DGID,			"dgid=%s" 		},
1810 	{ SRP_OPT_PKEY,			"pkey=%x" 		},
1811 	{ SRP_OPT_SERVICE_ID,		"service_id=%s"		},
1812 	{ SRP_OPT_MAX_SECT,		"max_sect=%d" 		},
1813 	{ SRP_OPT_MAX_CMD_PER_LUN,	"max_cmd_per_lun=%d" 	},
1814 	{ SRP_OPT_IO_CLASS,		"io_class=%x"		},
1815 	{ SRP_OPT_INITIATOR_EXT,	"initiator_ext=%s"	},
1816 	{ SRP_OPT_ERR,			NULL 			}
1817 };
1818 
1819 static int srp_parse_options(const char *buf, struct srp_target_port *target)
1820 {
1821 	char *options, *sep_opt;
1822 	char *p;
1823 	char dgid[3];
1824 	substring_t args[MAX_OPT_ARGS];
1825 	int opt_mask = 0;
1826 	int token;
1827 	int ret = -EINVAL;
1828 	int i;
1829 
1830 	options = kstrdup(buf, GFP_KERNEL);
1831 	if (!options)
1832 		return -ENOMEM;
1833 
1834 	sep_opt = options;
1835 	while ((p = strsep(&sep_opt, ",")) != NULL) {
1836 		if (!*p)
1837 			continue;
1838 
1839 		token = match_token(p, srp_opt_tokens, args);
1840 		opt_mask |= token;
1841 
1842 		switch (token) {
1843 		case SRP_OPT_ID_EXT:
1844 			p = match_strdup(args);
1845 			if (!p) {
1846 				ret = -ENOMEM;
1847 				goto out;
1848 			}
1849 			target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
1850 			kfree(p);
1851 			break;
1852 
1853 		case SRP_OPT_IOC_GUID:
1854 			p = match_strdup(args);
1855 			if (!p) {
1856 				ret = -ENOMEM;
1857 				goto out;
1858 			}
1859 			target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
1860 			kfree(p);
1861 			break;
1862 
1863 		case SRP_OPT_DGID:
1864 			p = match_strdup(args);
1865 			if (!p) {
1866 				ret = -ENOMEM;
1867 				goto out;
1868 			}
1869 			if (strlen(p) != 32) {
1870 				printk(KERN_WARNING PFX "bad dest GID parameter '%s'\n", p);
1871 				kfree(p);
1872 				goto out;
1873 			}
1874 
1875 			for (i = 0; i < 16; ++i) {
1876 				strlcpy(dgid, p + i * 2, 3);
1877 				target->path.dgid.raw[i] = simple_strtoul(dgid, NULL, 16);
1878 			}
1879 			kfree(p);
1880 			memcpy(target->orig_dgid, target->path.dgid.raw, 16);
1881 			break;
1882 
1883 		case SRP_OPT_PKEY:
1884 			if (match_hex(args, &token)) {
1885 				printk(KERN_WARNING PFX "bad P_Key parameter '%s'\n", p);
1886 				goto out;
1887 			}
1888 			target->path.pkey = cpu_to_be16(token);
1889 			break;
1890 
1891 		case SRP_OPT_SERVICE_ID:
1892 			p = match_strdup(args);
1893 			if (!p) {
1894 				ret = -ENOMEM;
1895 				goto out;
1896 			}
1897 			target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
1898 			target->path.service_id = target->service_id;
1899 			kfree(p);
1900 			break;
1901 
1902 		case SRP_OPT_MAX_SECT:
1903 			if (match_int(args, &token)) {
1904 				printk(KERN_WARNING PFX "bad max sect parameter '%s'\n", p);
1905 				goto out;
1906 			}
1907 			target->scsi_host->max_sectors = token;
1908 			break;
1909 
1910 		case SRP_OPT_MAX_CMD_PER_LUN:
1911 			if (match_int(args, &token)) {
1912 				printk(KERN_WARNING PFX "bad max cmd_per_lun parameter '%s'\n", p);
1913 				goto out;
1914 			}
1915 			target->scsi_host->cmd_per_lun = min(token, SRP_CMD_SQ_SIZE);
1916 			break;
1917 
1918 		case SRP_OPT_IO_CLASS:
1919 			if (match_hex(args, &token)) {
1920 				printk(KERN_WARNING PFX "bad  IO class parameter '%s' \n", p);
1921 				goto out;
1922 			}
1923 			if (token != SRP_REV10_IB_IO_CLASS &&
1924 			    token != SRP_REV16A_IB_IO_CLASS) {
1925 				printk(KERN_WARNING PFX "unknown IO class parameter value"
1926 				       " %x specified (use %x or %x).\n",
1927 				       token, SRP_REV10_IB_IO_CLASS, SRP_REV16A_IB_IO_CLASS);
1928 				goto out;
1929 			}
1930 			target->io_class = token;
1931 			break;
1932 
1933 		case SRP_OPT_INITIATOR_EXT:
1934 			p = match_strdup(args);
1935 			if (!p) {
1936 				ret = -ENOMEM;
1937 				goto out;
1938 			}
1939 			target->initiator_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
1940 			kfree(p);
1941 			break;
1942 
1943 		default:
1944 			printk(KERN_WARNING PFX "unknown parameter or missing value "
1945 			       "'%s' in target creation request\n", p);
1946 			goto out;
1947 		}
1948 	}
1949 
1950 	if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
1951 		ret = 0;
1952 	else
1953 		for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
1954 			if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
1955 			    !(srp_opt_tokens[i].token & opt_mask))
1956 				printk(KERN_WARNING PFX "target creation request is "
1957 				       "missing parameter '%s'\n",
1958 				       srp_opt_tokens[i].pattern);
1959 
1960 out:
1961 	kfree(options);
1962 	return ret;
1963 }
1964 
1965 static ssize_t srp_create_target(struct device *dev,
1966 				 struct device_attribute *attr,
1967 				 const char *buf, size_t count)
1968 {
1969 	struct srp_host *host =
1970 		container_of(dev, struct srp_host, dev);
1971 	struct Scsi_Host *target_host;
1972 	struct srp_target_port *target;
1973 	int ret;
1974 	int i;
1975 
1976 	target_host = scsi_host_alloc(&srp_template,
1977 				      sizeof (struct srp_target_port));
1978 	if (!target_host)
1979 		return -ENOMEM;
1980 
1981 	target_host->transportt = ib_srp_transport_template;
1982 	target_host->max_lun     = SRP_MAX_LUN;
1983 	target_host->max_cmd_len = sizeof ((struct srp_cmd *) (void *) 0L)->cdb;
1984 
1985 	target = host_to_target(target_host);
1986 
1987 	target->io_class   = SRP_REV16A_IB_IO_CLASS;
1988 	target->scsi_host  = target_host;
1989 	target->srp_host   = host;
1990 
1991 	INIT_LIST_HEAD(&target->free_reqs);
1992 	INIT_LIST_HEAD(&target->req_queue);
1993 	for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
1994 		target->req_ring[i].index = i;
1995 		list_add_tail(&target->req_ring[i].list, &target->free_reqs);
1996 	}
1997 
1998 	ret = srp_parse_options(buf, target);
1999 	if (ret)
2000 		goto err;
2001 
2002 	ib_query_gid(host->srp_dev->dev, host->port, 0, &target->path.sgid);
2003 
2004 	shost_printk(KERN_DEBUG, target->scsi_host, PFX
2005 		     "new target: id_ext %016llx ioc_guid %016llx pkey %04x "
2006 		     "service_id %016llx dgid %pI6\n",
2007 	       (unsigned long long) be64_to_cpu(target->id_ext),
2008 	       (unsigned long long) be64_to_cpu(target->ioc_guid),
2009 	       be16_to_cpu(target->path.pkey),
2010 	       (unsigned long long) be64_to_cpu(target->service_id),
2011 	       target->path.dgid.raw);
2012 
2013 	ret = srp_create_target_ib(target);
2014 	if (ret)
2015 		goto err;
2016 
2017 	ret = srp_new_cm_id(target);
2018 	if (ret)
2019 		goto err_free;
2020 
2021 	target->qp_in_error = 0;
2022 	ret = srp_connect_target(target);
2023 	if (ret) {
2024 		shost_printk(KERN_ERR, target->scsi_host,
2025 			     PFX "Connection failed\n");
2026 		goto err_cm_id;
2027 	}
2028 
2029 	ret = srp_add_target(host, target);
2030 	if (ret)
2031 		goto err_disconnect;
2032 
2033 	return count;
2034 
2035 err_disconnect:
2036 	srp_disconnect_target(target);
2037 
2038 err_cm_id:
2039 	ib_destroy_cm_id(target->cm_id);
2040 
2041 err_free:
2042 	srp_free_target_ib(target);
2043 
2044 err:
2045 	scsi_host_put(target_host);
2046 
2047 	return ret;
2048 }
2049 
2050 static DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
2051 
2052 static ssize_t show_ibdev(struct device *dev, struct device_attribute *attr,
2053 			  char *buf)
2054 {
2055 	struct srp_host *host = container_of(dev, struct srp_host, dev);
2056 
2057 	return sprintf(buf, "%s\n", host->srp_dev->dev->name);
2058 }
2059 
2060 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
2061 
2062 static ssize_t show_port(struct device *dev, struct device_attribute *attr,
2063 			 char *buf)
2064 {
2065 	struct srp_host *host = container_of(dev, struct srp_host, dev);
2066 
2067 	return sprintf(buf, "%d\n", host->port);
2068 }
2069 
2070 static DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
2071 
2072 static struct srp_host *srp_add_port(struct srp_device *device, u8 port)
2073 {
2074 	struct srp_host *host;
2075 
2076 	host = kzalloc(sizeof *host, GFP_KERNEL);
2077 	if (!host)
2078 		return NULL;
2079 
2080 	INIT_LIST_HEAD(&host->target_list);
2081 	spin_lock_init(&host->target_lock);
2082 	init_completion(&host->released);
2083 	host->srp_dev = device;
2084 	host->port = port;
2085 
2086 	host->dev.class = &srp_class;
2087 	host->dev.parent = device->dev->dma_device;
2088 	dev_set_name(&host->dev, "srp-%s-%d", device->dev->name, port);
2089 
2090 	if (device_register(&host->dev))
2091 		goto free_host;
2092 	if (device_create_file(&host->dev, &dev_attr_add_target))
2093 		goto err_class;
2094 	if (device_create_file(&host->dev, &dev_attr_ibdev))
2095 		goto err_class;
2096 	if (device_create_file(&host->dev, &dev_attr_port))
2097 		goto err_class;
2098 
2099 	return host;
2100 
2101 err_class:
2102 	device_unregister(&host->dev);
2103 
2104 free_host:
2105 	kfree(host);
2106 
2107 	return NULL;
2108 }
2109 
2110 static void srp_add_one(struct ib_device *device)
2111 {
2112 	struct srp_device *srp_dev;
2113 	struct ib_device_attr *dev_attr;
2114 	struct ib_fmr_pool_param fmr_param;
2115 	struct srp_host *host;
2116 	int s, e, p;
2117 
2118 	dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
2119 	if (!dev_attr)
2120 		return;
2121 
2122 	if (ib_query_device(device, dev_attr)) {
2123 		printk(KERN_WARNING PFX "Query device failed for %s\n",
2124 		       device->name);
2125 		goto free_attr;
2126 	}
2127 
2128 	srp_dev = kmalloc(sizeof *srp_dev, GFP_KERNEL);
2129 	if (!srp_dev)
2130 		goto free_attr;
2131 
2132 	/*
2133 	 * Use the smallest page size supported by the HCA, down to a
2134 	 * minimum of 512 bytes (which is the smallest sector that a
2135 	 * SCSI command will ever carry).
2136 	 */
2137 	srp_dev->fmr_page_shift = max(9, ffs(dev_attr->page_size_cap) - 1);
2138 	srp_dev->fmr_page_size  = 1 << srp_dev->fmr_page_shift;
2139 	srp_dev->fmr_page_mask  = ~((u64) srp_dev->fmr_page_size - 1);
2140 
2141 	INIT_LIST_HEAD(&srp_dev->dev_list);
2142 
2143 	srp_dev->dev = device;
2144 	srp_dev->pd  = ib_alloc_pd(device);
2145 	if (IS_ERR(srp_dev->pd))
2146 		goto free_dev;
2147 
2148 	srp_dev->mr = ib_get_dma_mr(srp_dev->pd,
2149 				    IB_ACCESS_LOCAL_WRITE |
2150 				    IB_ACCESS_REMOTE_READ |
2151 				    IB_ACCESS_REMOTE_WRITE);
2152 	if (IS_ERR(srp_dev->mr))
2153 		goto err_pd;
2154 
2155 	memset(&fmr_param, 0, sizeof fmr_param);
2156 	fmr_param.pool_size	    = SRP_FMR_POOL_SIZE;
2157 	fmr_param.dirty_watermark   = SRP_FMR_DIRTY_SIZE;
2158 	fmr_param.cache		    = 1;
2159 	fmr_param.max_pages_per_fmr = SRP_FMR_SIZE;
2160 	fmr_param.page_shift	    = srp_dev->fmr_page_shift;
2161 	fmr_param.access	    = (IB_ACCESS_LOCAL_WRITE |
2162 				       IB_ACCESS_REMOTE_WRITE |
2163 				       IB_ACCESS_REMOTE_READ);
2164 
2165 	srp_dev->fmr_pool = ib_create_fmr_pool(srp_dev->pd, &fmr_param);
2166 	if (IS_ERR(srp_dev->fmr_pool))
2167 		srp_dev->fmr_pool = NULL;
2168 
2169 	if (device->node_type == RDMA_NODE_IB_SWITCH) {
2170 		s = 0;
2171 		e = 0;
2172 	} else {
2173 		s = 1;
2174 		e = device->phys_port_cnt;
2175 	}
2176 
2177 	for (p = s; p <= e; ++p) {
2178 		host = srp_add_port(srp_dev, p);
2179 		if (host)
2180 			list_add_tail(&host->list, &srp_dev->dev_list);
2181 	}
2182 
2183 	ib_set_client_data(device, &srp_client, srp_dev);
2184 
2185 	goto free_attr;
2186 
2187 err_pd:
2188 	ib_dealloc_pd(srp_dev->pd);
2189 
2190 free_dev:
2191 	kfree(srp_dev);
2192 
2193 free_attr:
2194 	kfree(dev_attr);
2195 }
2196 
2197 static void srp_remove_one(struct ib_device *device)
2198 {
2199 	struct srp_device *srp_dev;
2200 	struct srp_host *host, *tmp_host;
2201 	LIST_HEAD(target_list);
2202 	struct srp_target_port *target, *tmp_target;
2203 
2204 	srp_dev = ib_get_client_data(device, &srp_client);
2205 
2206 	list_for_each_entry_safe(host, tmp_host, &srp_dev->dev_list, list) {
2207 		device_unregister(&host->dev);
2208 		/*
2209 		 * Wait for the sysfs entry to go away, so that no new
2210 		 * target ports can be created.
2211 		 */
2212 		wait_for_completion(&host->released);
2213 
2214 		/*
2215 		 * Mark all target ports as removed, so we stop queueing
2216 		 * commands and don't try to reconnect.
2217 		 */
2218 		spin_lock(&host->target_lock);
2219 		list_for_each_entry(target, &host->target_list, list) {
2220 			spin_lock_irq(target->scsi_host->host_lock);
2221 			target->state = SRP_TARGET_REMOVED;
2222 			spin_unlock_irq(target->scsi_host->host_lock);
2223 		}
2224 		spin_unlock(&host->target_lock);
2225 
2226 		/*
2227 		 * Wait for any reconnection tasks that may have
2228 		 * started before we marked our target ports as
2229 		 * removed, and any target port removal tasks.
2230 		 */
2231 		flush_scheduled_work();
2232 
2233 		list_for_each_entry_safe(target, tmp_target,
2234 					 &host->target_list, list) {
2235 			srp_remove_host(target->scsi_host);
2236 			scsi_remove_host(target->scsi_host);
2237 			srp_disconnect_target(target);
2238 			ib_destroy_cm_id(target->cm_id);
2239 			srp_free_target_ib(target);
2240 			scsi_host_put(target->scsi_host);
2241 		}
2242 
2243 		kfree(host);
2244 	}
2245 
2246 	if (srp_dev->fmr_pool)
2247 		ib_destroy_fmr_pool(srp_dev->fmr_pool);
2248 	ib_dereg_mr(srp_dev->mr);
2249 	ib_dealloc_pd(srp_dev->pd);
2250 
2251 	kfree(srp_dev);
2252 }
2253 
2254 static struct srp_function_template ib_srp_transport_functions = {
2255 };
2256 
2257 static int __init srp_init_module(void)
2258 {
2259 	int ret;
2260 
2261 	BUILD_BUG_ON_NOT_POWER_OF_2(SRP_SQ_SIZE);
2262 	BUILD_BUG_ON_NOT_POWER_OF_2(SRP_RQ_SIZE);
2263 
2264 	if (srp_sg_tablesize > 255) {
2265 		printk(KERN_WARNING PFX "Clamping srp_sg_tablesize to 255\n");
2266 		srp_sg_tablesize = 255;
2267 	}
2268 
2269 	ib_srp_transport_template =
2270 		srp_attach_transport(&ib_srp_transport_functions);
2271 	if (!ib_srp_transport_template)
2272 		return -ENOMEM;
2273 
2274 	srp_template.sg_tablesize = srp_sg_tablesize;
2275 	srp_max_iu_len = (sizeof (struct srp_cmd) +
2276 			  sizeof (struct srp_indirect_buf) +
2277 			  srp_sg_tablesize * 16);
2278 
2279 	ret = class_register(&srp_class);
2280 	if (ret) {
2281 		printk(KERN_ERR PFX "couldn't register class infiniband_srp\n");
2282 		srp_release_transport(ib_srp_transport_template);
2283 		return ret;
2284 	}
2285 
2286 	ib_sa_register_client(&srp_sa_client);
2287 
2288 	ret = ib_register_client(&srp_client);
2289 	if (ret) {
2290 		printk(KERN_ERR PFX "couldn't register IB client\n");
2291 		srp_release_transport(ib_srp_transport_template);
2292 		ib_sa_unregister_client(&srp_sa_client);
2293 		class_unregister(&srp_class);
2294 		return ret;
2295 	}
2296 
2297 	return 0;
2298 }
2299 
2300 static void __exit srp_cleanup_module(void)
2301 {
2302 	ib_unregister_client(&srp_client);
2303 	ib_sa_unregister_client(&srp_sa_client);
2304 	class_unregister(&srp_class);
2305 	srp_release_transport(ib_srp_transport_template);
2306 }
2307 
2308 module_init(srp_init_module);
2309 module_exit(srp_cleanup_module);
2310