xref: /linux/drivers/infiniband/ulp/srp/ib_srp.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
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  * $Id: ib_srp.c 3932 2005-11-01 17:19:29Z roland $
33  */
34 
35 #include <linux/version.h>
36 #include <linux/module.h>
37 #include <linux/init.h>
38 #include <linux/slab.h>
39 #include <linux/err.h>
40 #include <linux/string.h>
41 #include <linux/parser.h>
42 #include <linux/random.h>
43 
44 #include <asm/atomic.h>
45 
46 #include <scsi/scsi.h>
47 #include <scsi/scsi_device.h>
48 #include <scsi/scsi_dbg.h>
49 #include <scsi/srp.h>
50 
51 #include <rdma/ib_cache.h>
52 
53 #include "ib_srp.h"
54 
55 #define DRV_NAME	"ib_srp"
56 #define PFX		DRV_NAME ": "
57 #define DRV_VERSION	"0.2"
58 #define DRV_RELDATE	"November 1, 2005"
59 
60 MODULE_AUTHOR("Roland Dreier");
61 MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol initiator "
62 		   "v" DRV_VERSION " (" DRV_RELDATE ")");
63 MODULE_LICENSE("Dual BSD/GPL");
64 
65 static int topspin_workarounds = 1;
66 
67 module_param(topspin_workarounds, int, 0444);
68 MODULE_PARM_DESC(topspin_workarounds,
69 		 "Enable workarounds for Topspin/Cisco SRP target bugs if != 0");
70 
71 static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
72 
73 static void srp_add_one(struct ib_device *device);
74 static void srp_remove_one(struct ib_device *device);
75 static void srp_completion(struct ib_cq *cq, void *target_ptr);
76 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);
77 
78 static struct ib_client srp_client = {
79 	.name   = "srp",
80 	.add    = srp_add_one,
81 	.remove = srp_remove_one
82 };
83 
84 static inline struct srp_target_port *host_to_target(struct Scsi_Host *host)
85 {
86 	return (struct srp_target_port *) host->hostdata;
87 }
88 
89 static const char *srp_target_info(struct Scsi_Host *host)
90 {
91 	return host_to_target(host)->target_name;
92 }
93 
94 static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
95 				   gfp_t gfp_mask,
96 				   enum dma_data_direction direction)
97 {
98 	struct srp_iu *iu;
99 
100 	iu = kmalloc(sizeof *iu, gfp_mask);
101 	if (!iu)
102 		goto out;
103 
104 	iu->buf = kzalloc(size, gfp_mask);
105 	if (!iu->buf)
106 		goto out_free_iu;
107 
108 	iu->dma = dma_map_single(host->dev->dma_device, iu->buf, size, direction);
109 	if (dma_mapping_error(iu->dma))
110 		goto out_free_buf;
111 
112 	iu->size      = size;
113 	iu->direction = direction;
114 
115 	return iu;
116 
117 out_free_buf:
118 	kfree(iu->buf);
119 out_free_iu:
120 	kfree(iu);
121 out:
122 	return NULL;
123 }
124 
125 static void srp_free_iu(struct srp_host *host, struct srp_iu *iu)
126 {
127 	if (!iu)
128 		return;
129 
130 	dma_unmap_single(host->dev->dma_device, iu->dma, iu->size, iu->direction);
131 	kfree(iu->buf);
132 	kfree(iu);
133 }
134 
135 static void srp_qp_event(struct ib_event *event, void *context)
136 {
137 	printk(KERN_ERR PFX "QP event %d\n", event->event);
138 }
139 
140 static int srp_init_qp(struct srp_target_port *target,
141 		       struct ib_qp *qp)
142 {
143 	struct ib_qp_attr *attr;
144 	int ret;
145 
146 	attr = kmalloc(sizeof *attr, GFP_KERNEL);
147 	if (!attr)
148 		return -ENOMEM;
149 
150 	ret = ib_find_cached_pkey(target->srp_host->dev,
151 				  target->srp_host->port,
152 				  be16_to_cpu(target->path.pkey),
153 				  &attr->pkey_index);
154 	if (ret)
155 		goto out;
156 
157 	attr->qp_state        = IB_QPS_INIT;
158 	attr->qp_access_flags = (IB_ACCESS_REMOTE_READ |
159 				    IB_ACCESS_REMOTE_WRITE);
160 	attr->port_num        = target->srp_host->port;
161 
162 	ret = ib_modify_qp(qp, attr,
163 			   IB_QP_STATE		|
164 			   IB_QP_PKEY_INDEX	|
165 			   IB_QP_ACCESS_FLAGS	|
166 			   IB_QP_PORT);
167 
168 out:
169 	kfree(attr);
170 	return ret;
171 }
172 
173 static int srp_create_target_ib(struct srp_target_port *target)
174 {
175 	struct ib_qp_init_attr *init_attr;
176 	int ret;
177 
178 	init_attr = kzalloc(sizeof *init_attr, GFP_KERNEL);
179 	if (!init_attr)
180 		return -ENOMEM;
181 
182 	target->cq = ib_create_cq(target->srp_host->dev, srp_completion,
183 				  NULL, target, SRP_CQ_SIZE);
184 	if (IS_ERR(target->cq)) {
185 		ret = PTR_ERR(target->cq);
186 		goto out;
187 	}
188 
189 	ib_req_notify_cq(target->cq, IB_CQ_NEXT_COMP);
190 
191 	init_attr->event_handler       = srp_qp_event;
192 	init_attr->cap.max_send_wr     = SRP_SQ_SIZE;
193 	init_attr->cap.max_recv_wr     = SRP_RQ_SIZE;
194 	init_attr->cap.max_recv_sge    = 1;
195 	init_attr->cap.max_send_sge    = 1;
196 	init_attr->sq_sig_type         = IB_SIGNAL_ALL_WR;
197 	init_attr->qp_type             = IB_QPT_RC;
198 	init_attr->send_cq             = target->cq;
199 	init_attr->recv_cq             = target->cq;
200 
201 	target->qp = ib_create_qp(target->srp_host->pd, init_attr);
202 	if (IS_ERR(target->qp)) {
203 		ret = PTR_ERR(target->qp);
204 		ib_destroy_cq(target->cq);
205 		goto out;
206 	}
207 
208 	ret = srp_init_qp(target, target->qp);
209 	if (ret) {
210 		ib_destroy_qp(target->qp);
211 		ib_destroy_cq(target->cq);
212 		goto out;
213 	}
214 
215 out:
216 	kfree(init_attr);
217 	return ret;
218 }
219 
220 static void srp_free_target_ib(struct srp_target_port *target)
221 {
222 	int i;
223 
224 	ib_destroy_qp(target->qp);
225 	ib_destroy_cq(target->cq);
226 
227 	for (i = 0; i < SRP_RQ_SIZE; ++i)
228 		srp_free_iu(target->srp_host, target->rx_ring[i]);
229 	for (i = 0; i < SRP_SQ_SIZE + 1; ++i)
230 		srp_free_iu(target->srp_host, target->tx_ring[i]);
231 }
232 
233 static void srp_path_rec_completion(int status,
234 				    struct ib_sa_path_rec *pathrec,
235 				    void *target_ptr)
236 {
237 	struct srp_target_port *target = target_ptr;
238 
239 	target->status = status;
240 	if (status)
241 		printk(KERN_ERR PFX "Got failed path rec status %d\n", status);
242 	else
243 		target->path = *pathrec;
244 	complete(&target->done);
245 }
246 
247 static int srp_lookup_path(struct srp_target_port *target)
248 {
249 	target->path.numb_path = 1;
250 
251 	init_completion(&target->done);
252 
253 	target->path_query_id = ib_sa_path_rec_get(target->srp_host->dev,
254 						   target->srp_host->port,
255 						   &target->path,
256 						   IB_SA_PATH_REC_DGID		|
257 						   IB_SA_PATH_REC_SGID		|
258 						   IB_SA_PATH_REC_NUMB_PATH	|
259 						   IB_SA_PATH_REC_PKEY,
260 						   SRP_PATH_REC_TIMEOUT_MS,
261 						   GFP_KERNEL,
262 						   srp_path_rec_completion,
263 						   target, &target->path_query);
264 	if (target->path_query_id < 0)
265 		return target->path_query_id;
266 
267 	wait_for_completion(&target->done);
268 
269 	if (target->status < 0)
270 		printk(KERN_WARNING PFX "Path record query failed\n");
271 
272 	return target->status;
273 }
274 
275 static int srp_send_req(struct srp_target_port *target)
276 {
277 	struct {
278 		struct ib_cm_req_param param;
279 		struct srp_login_req   priv;
280 	} *req = NULL;
281 	int status;
282 
283 	req = kzalloc(sizeof *req, GFP_KERNEL);
284 	if (!req)
285 		return -ENOMEM;
286 
287 	req->param.primary_path 	      = &target->path;
288 	req->param.alternate_path 	      = NULL;
289 	req->param.service_id 		      = target->service_id;
290 	req->param.qp_num 		      = target->qp->qp_num;
291 	req->param.qp_type 		      = target->qp->qp_type;
292 	req->param.private_data 	      = &req->priv;
293 	req->param.private_data_len 	      = sizeof req->priv;
294 	req->param.flow_control 	      = 1;
295 
296 	get_random_bytes(&req->param.starting_psn, 4);
297 	req->param.starting_psn 	     &= 0xffffff;
298 
299 	/*
300 	 * Pick some arbitrary defaults here; we could make these
301 	 * module parameters if anyone cared about setting them.
302 	 */
303 	req->param.responder_resources	      = 4;
304 	req->param.remote_cm_response_timeout = 20;
305 	req->param.local_cm_response_timeout  = 20;
306 	req->param.retry_count 		      = 7;
307 	req->param.rnr_retry_count 	      = 7;
308 	req->param.max_cm_retries 	      = 15;
309 
310 	req->priv.opcode     	= SRP_LOGIN_REQ;
311 	req->priv.tag        	= 0;
312 	req->priv.req_it_iu_len = cpu_to_be32(SRP_MAX_IU_LEN);
313 	req->priv.req_buf_fmt 	= cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
314 					      SRP_BUF_FORMAT_INDIRECT);
315 	memcpy(req->priv.initiator_port_id, target->srp_host->initiator_port_id, 16);
316 	/*
317 	 * Topspin/Cisco SRP targets will reject our login unless we
318 	 * zero out the first 8 bytes of our initiator port ID.  The
319 	 * second 8 bytes must be our local node GUID, but we always
320 	 * use that anyway.
321 	 */
322 	if (topspin_workarounds && !memcmp(&target->ioc_guid, topspin_oui, 3)) {
323 		printk(KERN_DEBUG PFX "Topspin/Cisco initiator port ID workaround "
324 		       "activated for target GUID %016llx\n",
325 		       (unsigned long long) be64_to_cpu(target->ioc_guid));
326 		memset(req->priv.initiator_port_id, 0, 8);
327 	}
328 	memcpy(req->priv.target_port_id,     &target->id_ext, 8);
329 	memcpy(req->priv.target_port_id + 8, &target->ioc_guid, 8);
330 
331 	status = ib_send_cm_req(target->cm_id, &req->param);
332 
333 	kfree(req);
334 
335 	return status;
336 }
337 
338 static void srp_disconnect_target(struct srp_target_port *target)
339 {
340 	/* XXX should send SRP_I_LOGOUT request */
341 
342 	init_completion(&target->done);
343 	ib_send_cm_dreq(target->cm_id, NULL, 0);
344 	wait_for_completion(&target->done);
345 }
346 
347 static void srp_remove_work(void *target_ptr)
348 {
349 	struct srp_target_port *target = target_ptr;
350 
351 	spin_lock_irq(target->scsi_host->host_lock);
352 	if (target->state != SRP_TARGET_DEAD) {
353 		spin_unlock_irq(target->scsi_host->host_lock);
354 		scsi_host_put(target->scsi_host);
355 		return;
356 	}
357 	target->state = SRP_TARGET_REMOVED;
358 	spin_unlock_irq(target->scsi_host->host_lock);
359 
360 	down(&target->srp_host->target_mutex);
361 	list_del(&target->list);
362 	up(&target->srp_host->target_mutex);
363 
364 	scsi_remove_host(target->scsi_host);
365 	ib_destroy_cm_id(target->cm_id);
366 	srp_free_target_ib(target);
367 	scsi_host_put(target->scsi_host);
368 	/* And another put to really free the target port... */
369 	scsi_host_put(target->scsi_host);
370 }
371 
372 static int srp_connect_target(struct srp_target_port *target)
373 {
374 	int ret;
375 
376 	ret = srp_lookup_path(target);
377 	if (ret)
378 		return ret;
379 
380 	while (1) {
381 		init_completion(&target->done);
382 		ret = srp_send_req(target);
383 		if (ret)
384 			return ret;
385 		wait_for_completion(&target->done);
386 
387 		/*
388 		 * The CM event handling code will set status to
389 		 * SRP_PORT_REDIRECT if we get a port redirect REJ
390 		 * back, or SRP_DLID_REDIRECT if we get a lid/qp
391 		 * redirect REJ back.
392 		 */
393 		switch (target->status) {
394 		case 0:
395 			return 0;
396 
397 		case SRP_PORT_REDIRECT:
398 			ret = srp_lookup_path(target);
399 			if (ret)
400 				return ret;
401 			break;
402 
403 		case SRP_DLID_REDIRECT:
404 			break;
405 
406 		default:
407 			return target->status;
408 		}
409 	}
410 }
411 
412 static int srp_reconnect_target(struct srp_target_port *target)
413 {
414 	struct ib_cm_id *new_cm_id;
415 	struct ib_qp_attr qp_attr;
416 	struct srp_request *req;
417 	struct ib_wc wc;
418 	int ret;
419 	int i;
420 
421 	spin_lock_irq(target->scsi_host->host_lock);
422 	if (target->state != SRP_TARGET_LIVE) {
423 		spin_unlock_irq(target->scsi_host->host_lock);
424 		return -EAGAIN;
425 	}
426 	target->state = SRP_TARGET_CONNECTING;
427 	spin_unlock_irq(target->scsi_host->host_lock);
428 
429 	srp_disconnect_target(target);
430 	/*
431 	 * Now get a new local CM ID so that we avoid confusing the
432 	 * target in case things are really fouled up.
433 	 */
434 	new_cm_id = ib_create_cm_id(target->srp_host->dev,
435 				    srp_cm_handler, target);
436 	if (IS_ERR(new_cm_id)) {
437 		ret = PTR_ERR(new_cm_id);
438 		goto err;
439 	}
440 	ib_destroy_cm_id(target->cm_id);
441 	target->cm_id = new_cm_id;
442 
443 	qp_attr.qp_state = IB_QPS_RESET;
444 	ret = ib_modify_qp(target->qp, &qp_attr, IB_QP_STATE);
445 	if (ret)
446 		goto err;
447 
448 	ret = srp_init_qp(target, target->qp);
449 	if (ret)
450 		goto err;
451 
452 	while (ib_poll_cq(target->cq, 1, &wc) > 0)
453 		; /* nothing */
454 
455 	list_for_each_entry(req, &target->req_queue, list) {
456 		req->scmnd->result = DID_RESET << 16;
457 		req->scmnd->scsi_done(req->scmnd);
458 	}
459 
460 	target->rx_head	 = 0;
461 	target->tx_head	 = 0;
462 	target->tx_tail  = 0;
463 	target->req_head = 0;
464 	for (i = 0; i < SRP_SQ_SIZE - 1; ++i)
465 		target->req_ring[i].next = i + 1;
466 	target->req_ring[SRP_SQ_SIZE - 1].next = -1;
467 	INIT_LIST_HEAD(&target->req_queue);
468 
469 	ret = srp_connect_target(target);
470 	if (ret)
471 		goto err;
472 
473 	spin_lock_irq(target->scsi_host->host_lock);
474 	if (target->state == SRP_TARGET_CONNECTING) {
475 		ret = 0;
476 		target->state = SRP_TARGET_LIVE;
477 	} else
478 		ret = -EAGAIN;
479 	spin_unlock_irq(target->scsi_host->host_lock);
480 
481 	return ret;
482 
483 err:
484 	printk(KERN_ERR PFX "reconnect failed (%d), removing target port.\n", ret);
485 
486 	/*
487 	 * We couldn't reconnect, so kill our target port off.
488 	 * However, we have to defer the real removal because we might
489 	 * be in the context of the SCSI error handler now, which
490 	 * would deadlock if we call scsi_remove_host().
491 	 */
492 	spin_lock_irq(target->scsi_host->host_lock);
493 	if (target->state == SRP_TARGET_CONNECTING) {
494 		target->state = SRP_TARGET_DEAD;
495 		INIT_WORK(&target->work, srp_remove_work, target);
496 		schedule_work(&target->work);
497 	}
498 	spin_unlock_irq(target->scsi_host->host_lock);
499 
500 	return ret;
501 }
502 
503 static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
504 			struct srp_request *req)
505 {
506 	struct srp_cmd *cmd = req->cmd->buf;
507 	int len;
508 	u8 fmt;
509 
510 	if (!scmnd->request_buffer || scmnd->sc_data_direction == DMA_NONE)
511 		return sizeof (struct srp_cmd);
512 
513 	if (scmnd->sc_data_direction != DMA_FROM_DEVICE &&
514 	    scmnd->sc_data_direction != DMA_TO_DEVICE) {
515 		printk(KERN_WARNING PFX "Unhandled data direction %d\n",
516 		       scmnd->sc_data_direction);
517 		return -EINVAL;
518 	}
519 
520 	if (scmnd->use_sg) {
521 		struct scatterlist *scat = scmnd->request_buffer;
522 		int n;
523 		int i;
524 
525 		n = dma_map_sg(target->srp_host->dev->dma_device,
526 			       scat, scmnd->use_sg, scmnd->sc_data_direction);
527 
528 		if (n == 1) {
529 			struct srp_direct_buf *buf = (void *) cmd->add_data;
530 
531 			fmt = SRP_DATA_DESC_DIRECT;
532 
533 			buf->va  = cpu_to_be64(sg_dma_address(scat));
534 			buf->key = cpu_to_be32(target->srp_host->mr->rkey);
535 			buf->len = cpu_to_be32(sg_dma_len(scat));
536 
537 			len = sizeof (struct srp_cmd) +
538 				sizeof (struct srp_direct_buf);
539 		} else {
540 			struct srp_indirect_buf *buf = (void *) cmd->add_data;
541 			u32 datalen = 0;
542 
543 			fmt = SRP_DATA_DESC_INDIRECT;
544 
545 			if (scmnd->sc_data_direction == DMA_TO_DEVICE)
546 				cmd->data_out_desc_cnt = n;
547 			else
548 				cmd->data_in_desc_cnt = n;
549 
550 			buf->table_desc.va  = cpu_to_be64(req->cmd->dma +
551 							  sizeof *cmd +
552 							  sizeof *buf);
553 			buf->table_desc.key =
554 				cpu_to_be32(target->srp_host->mr->rkey);
555 			buf->table_desc.len =
556 				cpu_to_be32(n * sizeof (struct srp_direct_buf));
557 
558 			for (i = 0; i < n; ++i) {
559 				buf->desc_list[i].va  = cpu_to_be64(sg_dma_address(&scat[i]));
560 				buf->desc_list[i].key =
561 					cpu_to_be32(target->srp_host->mr->rkey);
562 				buf->desc_list[i].len = cpu_to_be32(sg_dma_len(&scat[i]));
563 
564 				datalen += sg_dma_len(&scat[i]);
565 			}
566 
567 			buf->len = cpu_to_be32(datalen);
568 
569 			len = sizeof (struct srp_cmd) +
570 				sizeof (struct srp_indirect_buf) +
571 				n * sizeof (struct srp_direct_buf);
572 		}
573 	} else {
574 		struct srp_direct_buf *buf = (void *) cmd->add_data;
575 		dma_addr_t dma;
576 
577 		dma = dma_map_single(target->srp_host->dev->dma_device,
578 				     scmnd->request_buffer, scmnd->request_bufflen,
579 				     scmnd->sc_data_direction);
580 		if (dma_mapping_error(dma)) {
581 			printk(KERN_WARNING PFX "unable to map %p/%d (dir %d)\n",
582 			       scmnd->request_buffer, (int) scmnd->request_bufflen,
583 			       scmnd->sc_data_direction);
584 			return -EINVAL;
585 		}
586 
587 		pci_unmap_addr_set(req, direct_mapping, dma);
588 
589 		buf->va  = cpu_to_be64(dma);
590 		buf->key = cpu_to_be32(target->srp_host->mr->rkey);
591 		buf->len = cpu_to_be32(scmnd->request_bufflen);
592 
593 		fmt = SRP_DATA_DESC_DIRECT;
594 
595 		len = sizeof (struct srp_cmd) + sizeof (struct srp_direct_buf);
596 	}
597 
598 	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
599 		cmd->buf_fmt = fmt << 4;
600 	else
601 		cmd->buf_fmt = fmt;
602 
603 
604 	return len;
605 }
606 
607 static void srp_unmap_data(struct scsi_cmnd *scmnd,
608 			   struct srp_target_port *target,
609 			   struct srp_request *req)
610 {
611 	if (!scmnd->request_buffer ||
612 	    (scmnd->sc_data_direction != DMA_TO_DEVICE &&
613 	     scmnd->sc_data_direction != DMA_FROM_DEVICE))
614 	    return;
615 
616 	if (scmnd->use_sg)
617 		dma_unmap_sg(target->srp_host->dev->dma_device,
618 			     (struct scatterlist *) scmnd->request_buffer,
619 			     scmnd->use_sg, scmnd->sc_data_direction);
620 	else
621 		dma_unmap_single(target->srp_host->dev->dma_device,
622 				 pci_unmap_addr(req, direct_mapping),
623 				 scmnd->request_bufflen,
624 				 scmnd->sc_data_direction);
625 }
626 
627 static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
628 {
629 	struct srp_request *req;
630 	struct scsi_cmnd *scmnd;
631 	unsigned long flags;
632 	s32 delta;
633 
634 	delta = (s32) be32_to_cpu(rsp->req_lim_delta);
635 
636 	spin_lock_irqsave(target->scsi_host->host_lock, flags);
637 
638 	target->req_lim += delta;
639 
640 	req = &target->req_ring[rsp->tag & ~SRP_TAG_TSK_MGMT];
641 
642 	if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
643 		if (be32_to_cpu(rsp->resp_data_len) < 4)
644 			req->tsk_status = -1;
645 		else
646 			req->tsk_status = rsp->data[3];
647 		complete(&req->done);
648 	} else {
649 		scmnd 	      = req->scmnd;
650 		if (!scmnd)
651 			printk(KERN_ERR "Null scmnd for RSP w/tag %016llx\n",
652 			       (unsigned long long) rsp->tag);
653 		scmnd->result = rsp->status;
654 
655 		if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
656 			memcpy(scmnd->sense_buffer, rsp->data +
657 			       be32_to_cpu(rsp->resp_data_len),
658 			       min_t(int, be32_to_cpu(rsp->sense_data_len),
659 				     SCSI_SENSE_BUFFERSIZE));
660 		}
661 
662 		if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
663 			scmnd->resid = be32_to_cpu(rsp->data_out_res_cnt);
664 		else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
665 			scmnd->resid = be32_to_cpu(rsp->data_in_res_cnt);
666 
667 		srp_unmap_data(scmnd, target, req);
668 
669 		if (!req->tsk_mgmt) {
670 			req->scmnd = NULL;
671 			scmnd->host_scribble = (void *) -1L;
672 			scmnd->scsi_done(scmnd);
673 
674 			list_del(&req->list);
675 			req->next = target->req_head;
676 			target->req_head = rsp->tag & ~SRP_TAG_TSK_MGMT;
677 		} else
678 			req->cmd_done = 1;
679 	}
680 
681 	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
682 }
683 
684 static void srp_reconnect_work(void *target_ptr)
685 {
686 	struct srp_target_port *target = target_ptr;
687 
688 	srp_reconnect_target(target);
689 }
690 
691 static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
692 {
693 	struct srp_iu *iu;
694 	u8 opcode;
695 
696 	iu = target->rx_ring[wc->wr_id & ~SRP_OP_RECV];
697 
698 	dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
699 				target->max_ti_iu_len, DMA_FROM_DEVICE);
700 
701 	opcode = *(u8 *) iu->buf;
702 
703 	if (0) {
704 		int i;
705 
706 		printk(KERN_ERR PFX "recv completion, opcode 0x%02x\n", opcode);
707 
708 		for (i = 0; i < wc->byte_len; ++i) {
709 			if (i % 8 == 0)
710 				printk(KERN_ERR "  [%02x] ", i);
711 			printk(" %02x", ((u8 *) iu->buf)[i]);
712 			if ((i + 1) % 8 == 0)
713 				printk("\n");
714 		}
715 
716 		if (wc->byte_len % 8)
717 			printk("\n");
718 	}
719 
720 	switch (opcode) {
721 	case SRP_RSP:
722 		srp_process_rsp(target, iu->buf);
723 		break;
724 
725 	case SRP_T_LOGOUT:
726 		/* XXX Handle target logout */
727 		printk(KERN_WARNING PFX "Got target logout request\n");
728 		break;
729 
730 	default:
731 		printk(KERN_WARNING PFX "Unhandled SRP opcode 0x%02x\n", opcode);
732 		break;
733 	}
734 
735 	dma_sync_single_for_device(target->srp_host->dev->dma_device, iu->dma,
736 				   target->max_ti_iu_len, DMA_FROM_DEVICE);
737 }
738 
739 static void srp_completion(struct ib_cq *cq, void *target_ptr)
740 {
741 	struct srp_target_port *target = target_ptr;
742 	struct ib_wc wc;
743 	unsigned long flags;
744 
745 	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
746 	while (ib_poll_cq(cq, 1, &wc) > 0) {
747 		if (wc.status) {
748 			printk(KERN_ERR PFX "failed %s status %d\n",
749 			       wc.wr_id & SRP_OP_RECV ? "receive" : "send",
750 			       wc.status);
751 			spin_lock_irqsave(target->scsi_host->host_lock, flags);
752 			if (target->state == SRP_TARGET_LIVE)
753 				schedule_work(&target->work);
754 			spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
755 			break;
756 		}
757 
758 		if (wc.wr_id & SRP_OP_RECV)
759 			srp_handle_recv(target, &wc);
760 		else
761 			++target->tx_tail;
762 	}
763 }
764 
765 static int __srp_post_recv(struct srp_target_port *target)
766 {
767 	struct srp_iu *iu;
768 	struct ib_sge list;
769 	struct ib_recv_wr wr, *bad_wr;
770 	unsigned int next;
771 	int ret;
772 
773 	next 	 = target->rx_head & (SRP_RQ_SIZE - 1);
774 	wr.wr_id = next | SRP_OP_RECV;
775 	iu 	 = target->rx_ring[next];
776 
777 	list.addr   = iu->dma;
778 	list.length = iu->size;
779 	list.lkey   = target->srp_host->mr->lkey;
780 
781 	wr.next     = NULL;
782 	wr.sg_list  = &list;
783 	wr.num_sge  = 1;
784 
785 	ret = ib_post_recv(target->qp, &wr, &bad_wr);
786 	if (!ret)
787 		++target->rx_head;
788 
789 	return ret;
790 }
791 
792 static int srp_post_recv(struct srp_target_port *target)
793 {
794 	unsigned long flags;
795 	int ret;
796 
797 	spin_lock_irqsave(target->scsi_host->host_lock, flags);
798 	ret = __srp_post_recv(target);
799 	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
800 
801 	return ret;
802 }
803 
804 /*
805  * Must be called with target->scsi_host->host_lock held to protect
806  * req_lim and tx_head.
807  */
808 static struct srp_iu *__srp_get_tx_iu(struct srp_target_port *target)
809 {
810 	if (target->tx_head - target->tx_tail >= SRP_SQ_SIZE)
811 		return NULL;
812 
813 	return target->tx_ring[target->tx_head & SRP_SQ_SIZE];
814 }
815 
816 /*
817  * Must be called with target->scsi_host->host_lock held to protect
818  * req_lim and tx_head.
819  */
820 static int __srp_post_send(struct srp_target_port *target,
821 			   struct srp_iu *iu, int len)
822 {
823 	struct ib_sge list;
824 	struct ib_send_wr wr, *bad_wr;
825 	int ret = 0;
826 
827 	if (target->req_lim < 1) {
828 		printk(KERN_ERR PFX "Target has req_lim %d\n", target->req_lim);
829 		return -EAGAIN;
830 	}
831 
832 	list.addr   = iu->dma;
833 	list.length = len;
834 	list.lkey   = target->srp_host->mr->lkey;
835 
836 	wr.next       = NULL;
837 	wr.wr_id      = target->tx_head & SRP_SQ_SIZE;
838 	wr.sg_list    = &list;
839 	wr.num_sge    = 1;
840 	wr.opcode     = IB_WR_SEND;
841 	wr.send_flags = IB_SEND_SIGNALED;
842 
843 	ret = ib_post_send(target->qp, &wr, &bad_wr);
844 
845 	if (!ret) {
846 		++target->tx_head;
847 		--target->req_lim;
848 	}
849 
850 	return ret;
851 }
852 
853 static int srp_queuecommand(struct scsi_cmnd *scmnd,
854 			    void (*done)(struct scsi_cmnd *))
855 {
856 	struct srp_target_port *target = host_to_target(scmnd->device->host);
857 	struct srp_request *req;
858 	struct srp_iu *iu;
859 	struct srp_cmd *cmd;
860 	long req_index;
861 	int len;
862 
863 	if (target->state == SRP_TARGET_CONNECTING)
864 		goto err;
865 
866 	if (target->state == SRP_TARGET_DEAD ||
867 	    target->state == SRP_TARGET_REMOVED) {
868 		scmnd->result = DID_BAD_TARGET << 16;
869 		done(scmnd);
870 		return 0;
871 	}
872 
873 	iu = __srp_get_tx_iu(target);
874 	if (!iu)
875 		goto err;
876 
877 	dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
878 				SRP_MAX_IU_LEN, DMA_TO_DEVICE);
879 
880 	req_index = target->req_head;
881 
882 	scmnd->scsi_done     = done;
883 	scmnd->result        = 0;
884 	scmnd->host_scribble = (void *) req_index;
885 
886 	cmd = iu->buf;
887 	memset(cmd, 0, sizeof *cmd);
888 
889 	cmd->opcode = SRP_CMD;
890 	cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
891 	cmd->tag    = req_index;
892 	memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
893 
894 	req = &target->req_ring[req_index];
895 
896 	req->scmnd    = scmnd;
897 	req->cmd      = iu;
898 	req->cmd_done = 0;
899 	req->tsk_mgmt = NULL;
900 
901 	len = srp_map_data(scmnd, target, req);
902 	if (len < 0) {
903 		printk(KERN_ERR PFX "Failed to map data\n");
904 		goto err;
905 	}
906 
907 	if (__srp_post_recv(target)) {
908 		printk(KERN_ERR PFX "Recv failed\n");
909 		goto err_unmap;
910 	}
911 
912 	dma_sync_single_for_device(target->srp_host->dev->dma_device, iu->dma,
913 				   SRP_MAX_IU_LEN, DMA_TO_DEVICE);
914 
915 	if (__srp_post_send(target, iu, len)) {
916 		printk(KERN_ERR PFX "Send failed\n");
917 		goto err_unmap;
918 	}
919 
920 	target->req_head = req->next;
921 	list_add_tail(&req->list, &target->req_queue);
922 
923 	return 0;
924 
925 err_unmap:
926 	srp_unmap_data(scmnd, target, req);
927 
928 err:
929 	return SCSI_MLQUEUE_HOST_BUSY;
930 }
931 
932 static int srp_alloc_iu_bufs(struct srp_target_port *target)
933 {
934 	int i;
935 
936 	for (i = 0; i < SRP_RQ_SIZE; ++i) {
937 		target->rx_ring[i] = srp_alloc_iu(target->srp_host,
938 						  target->max_ti_iu_len,
939 						  GFP_KERNEL, DMA_FROM_DEVICE);
940 		if (!target->rx_ring[i])
941 			goto err;
942 	}
943 
944 	for (i = 0; i < SRP_SQ_SIZE + 1; ++i) {
945 		target->tx_ring[i] = srp_alloc_iu(target->srp_host,
946 						  SRP_MAX_IU_LEN,
947 						  GFP_KERNEL, DMA_TO_DEVICE);
948 		if (!target->tx_ring[i])
949 			goto err;
950 	}
951 
952 	return 0;
953 
954 err:
955 	for (i = 0; i < SRP_RQ_SIZE; ++i) {
956 		srp_free_iu(target->srp_host, target->rx_ring[i]);
957 		target->rx_ring[i] = NULL;
958 	}
959 
960 	for (i = 0; i < SRP_SQ_SIZE + 1; ++i) {
961 		srp_free_iu(target->srp_host, target->tx_ring[i]);
962 		target->tx_ring[i] = NULL;
963 	}
964 
965 	return -ENOMEM;
966 }
967 
968 static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
969 			       struct ib_cm_event *event,
970 			       struct srp_target_port *target)
971 {
972 	struct ib_class_port_info *cpi;
973 	int opcode;
974 
975 	switch (event->param.rej_rcvd.reason) {
976 	case IB_CM_REJ_PORT_CM_REDIRECT:
977 		cpi = event->param.rej_rcvd.ari;
978 		target->path.dlid = cpi->redirect_lid;
979 		target->path.pkey = cpi->redirect_pkey;
980 		cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
981 		memcpy(target->path.dgid.raw, cpi->redirect_gid, 16);
982 
983 		target->status = target->path.dlid ?
984 			SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
985 		break;
986 
987 	case IB_CM_REJ_PORT_REDIRECT:
988 		if (topspin_workarounds &&
989 		    !memcmp(&target->ioc_guid, topspin_oui, 3)) {
990 			/*
991 			 * Topspin/Cisco SRP gateways incorrectly send
992 			 * reject reason code 25 when they mean 24
993 			 * (port redirect).
994 			 */
995 			memcpy(target->path.dgid.raw,
996 			       event->param.rej_rcvd.ari, 16);
997 
998 			printk(KERN_DEBUG PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
999 			       (unsigned long long) be64_to_cpu(target->path.dgid.global.subnet_prefix),
1000 			       (unsigned long long) be64_to_cpu(target->path.dgid.global.interface_id));
1001 
1002 			target->status = SRP_PORT_REDIRECT;
1003 		} else {
1004 			printk(KERN_WARNING "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
1005 			target->status = -ECONNRESET;
1006 		}
1007 		break;
1008 
1009 	case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
1010 		printk(KERN_WARNING "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
1011 		target->status = -ECONNRESET;
1012 		break;
1013 
1014 	case IB_CM_REJ_CONSUMER_DEFINED:
1015 		opcode = *(u8 *) event->private_data;
1016 		if (opcode == SRP_LOGIN_REJ) {
1017 			struct srp_login_rej *rej = event->private_data;
1018 			u32 reason = be32_to_cpu(rej->reason);
1019 
1020 			if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
1021 				printk(KERN_WARNING PFX
1022 				       "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
1023 			else
1024 				printk(KERN_WARNING PFX
1025 				       "SRP LOGIN REJECTED, reason 0x%08x\n", reason);
1026 		} else
1027 			printk(KERN_WARNING "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
1028 			       " opcode 0x%02x\n", opcode);
1029 		target->status = -ECONNRESET;
1030 		break;
1031 
1032 	default:
1033 		printk(KERN_WARNING "  REJ reason 0x%x\n",
1034 		       event->param.rej_rcvd.reason);
1035 		target->status = -ECONNRESET;
1036 	}
1037 }
1038 
1039 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
1040 {
1041 	struct srp_target_port *target = cm_id->context;
1042 	struct ib_qp_attr *qp_attr = NULL;
1043 	int attr_mask = 0;
1044 	int comp = 0;
1045 	int opcode = 0;
1046 
1047 	switch (event->event) {
1048 	case IB_CM_REQ_ERROR:
1049 		printk(KERN_DEBUG PFX "Sending CM REQ failed\n");
1050 		comp = 1;
1051 		target->status = -ECONNRESET;
1052 		break;
1053 
1054 	case IB_CM_REP_RECEIVED:
1055 		comp = 1;
1056 		opcode = *(u8 *) event->private_data;
1057 
1058 		if (opcode == SRP_LOGIN_RSP) {
1059 			struct srp_login_rsp *rsp = event->private_data;
1060 
1061 			target->max_ti_iu_len = be32_to_cpu(rsp->max_ti_iu_len);
1062 			target->req_lim       = be32_to_cpu(rsp->req_lim_delta);
1063 
1064 			target->scsi_host->can_queue = min(target->req_lim,
1065 							   target->scsi_host->can_queue);
1066 		} else {
1067 			printk(KERN_WARNING PFX "Unhandled RSP opcode %#x\n", opcode);
1068 			target->status = -ECONNRESET;
1069 			break;
1070 		}
1071 
1072 		target->status = srp_alloc_iu_bufs(target);
1073 		if (target->status)
1074 			break;
1075 
1076 		qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
1077 		if (!qp_attr) {
1078 			target->status = -ENOMEM;
1079 			break;
1080 		}
1081 
1082 		qp_attr->qp_state = IB_QPS_RTR;
1083 		target->status = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1084 		if (target->status)
1085 			break;
1086 
1087 		target->status = ib_modify_qp(target->qp, qp_attr, attr_mask);
1088 		if (target->status)
1089 			break;
1090 
1091 		target->status = srp_post_recv(target);
1092 		if (target->status)
1093 			break;
1094 
1095 		qp_attr->qp_state = IB_QPS_RTS;
1096 		target->status = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1097 		if (target->status)
1098 			break;
1099 
1100 		target->status = ib_modify_qp(target->qp, qp_attr, attr_mask);
1101 		if (target->status)
1102 			break;
1103 
1104 		target->status = ib_send_cm_rtu(cm_id, NULL, 0);
1105 		if (target->status)
1106 			break;
1107 
1108 		break;
1109 
1110 	case IB_CM_REJ_RECEIVED:
1111 		printk(KERN_DEBUG PFX "REJ received\n");
1112 		comp = 1;
1113 
1114 		srp_cm_rej_handler(cm_id, event, target);
1115 		break;
1116 
1117 	case IB_CM_MRA_RECEIVED:
1118 		printk(KERN_ERR PFX "MRA received\n");
1119 		break;
1120 
1121 	case IB_CM_DREP_RECEIVED:
1122 		break;
1123 
1124 	case IB_CM_TIMEWAIT_EXIT:
1125 		printk(KERN_ERR PFX "connection closed\n");
1126 
1127 		comp = 1;
1128 		target->status = 0;
1129 		break;
1130 
1131 	default:
1132 		printk(KERN_WARNING PFX "Unhandled CM event %d\n", event->event);
1133 		break;
1134 	}
1135 
1136 	if (comp)
1137 		complete(&target->done);
1138 
1139 	kfree(qp_attr);
1140 
1141 	return 0;
1142 }
1143 
1144 static int srp_send_tsk_mgmt(struct scsi_cmnd *scmnd, u8 func)
1145 {
1146 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1147 	struct srp_request *req;
1148 	struct srp_iu *iu;
1149 	struct srp_tsk_mgmt *tsk_mgmt;
1150 	int req_index;
1151 	int ret = FAILED;
1152 
1153 	spin_lock_irq(target->scsi_host->host_lock);
1154 
1155 	if (scmnd->host_scribble == (void *) -1L)
1156 		goto out;
1157 
1158 	req_index = (long) scmnd->host_scribble;
1159 	printk(KERN_ERR "Abort for req_index %d\n", req_index);
1160 
1161 	req = &target->req_ring[req_index];
1162 	init_completion(&req->done);
1163 
1164 	iu = __srp_get_tx_iu(target);
1165 	if (!iu)
1166 		goto out;
1167 
1168 	tsk_mgmt = iu->buf;
1169 	memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
1170 
1171 	tsk_mgmt->opcode 	= SRP_TSK_MGMT;
1172 	tsk_mgmt->lun 		= cpu_to_be64((u64) scmnd->device->lun << 48);
1173 	tsk_mgmt->tag 		= req_index | SRP_TAG_TSK_MGMT;
1174 	tsk_mgmt->tsk_mgmt_func = func;
1175 	tsk_mgmt->task_tag 	= req_index;
1176 
1177 	if (__srp_post_send(target, iu, sizeof *tsk_mgmt))
1178 		goto out;
1179 
1180 	req->tsk_mgmt = iu;
1181 
1182 	spin_unlock_irq(target->scsi_host->host_lock);
1183 	if (!wait_for_completion_timeout(&req->done,
1184 					 msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
1185 		return FAILED;
1186 	spin_lock_irq(target->scsi_host->host_lock);
1187 
1188 	if (req->cmd_done) {
1189 		list_del(&req->list);
1190 		req->next = target->req_head;
1191 		target->req_head = req_index;
1192 
1193 		scmnd->scsi_done(scmnd);
1194 	} else if (!req->tsk_status) {
1195 		scmnd->result = DID_ABORT << 16;
1196 		ret = SUCCESS;
1197 	}
1198 
1199 out:
1200 	spin_unlock_irq(target->scsi_host->host_lock);
1201 	return ret;
1202 }
1203 
1204 static int srp_abort(struct scsi_cmnd *scmnd)
1205 {
1206 	printk(KERN_ERR "SRP abort called\n");
1207 
1208 	return srp_send_tsk_mgmt(scmnd, SRP_TSK_ABORT_TASK);
1209 }
1210 
1211 static int srp_reset_device(struct scsi_cmnd *scmnd)
1212 {
1213 	printk(KERN_ERR "SRP reset_device called\n");
1214 
1215 	return srp_send_tsk_mgmt(scmnd, SRP_TSK_LUN_RESET);
1216 }
1217 
1218 static int srp_reset_host(struct scsi_cmnd *scmnd)
1219 {
1220 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1221 	int ret = FAILED;
1222 
1223 	printk(KERN_ERR PFX "SRP reset_host called\n");
1224 
1225 	if (!srp_reconnect_target(target))
1226 		ret = SUCCESS;
1227 
1228 	return ret;
1229 }
1230 
1231 static struct scsi_host_template srp_template = {
1232 	.module				= THIS_MODULE,
1233 	.name				= DRV_NAME,
1234 	.info				= srp_target_info,
1235 	.queuecommand			= srp_queuecommand,
1236 	.eh_abort_handler		= srp_abort,
1237 	.eh_device_reset_handler	= srp_reset_device,
1238 	.eh_host_reset_handler		= srp_reset_host,
1239 	.can_queue			= SRP_SQ_SIZE,
1240 	.this_id			= -1,
1241 	.sg_tablesize			= SRP_MAX_INDIRECT,
1242 	.cmd_per_lun			= SRP_SQ_SIZE,
1243 	.use_clustering			= ENABLE_CLUSTERING
1244 };
1245 
1246 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
1247 {
1248 	sprintf(target->target_name, "SRP.T10:%016llX",
1249 		 (unsigned long long) be64_to_cpu(target->id_ext));
1250 
1251 	if (scsi_add_host(target->scsi_host, host->dev->dma_device))
1252 		return -ENODEV;
1253 
1254 	down(&host->target_mutex);
1255 	list_add_tail(&target->list, &host->target_list);
1256 	up(&host->target_mutex);
1257 
1258 	target->state = SRP_TARGET_LIVE;
1259 
1260 	/* XXX: are we supposed to have a definition of SCAN_WILD_CARD ?? */
1261 	scsi_scan_target(&target->scsi_host->shost_gendev,
1262 			 0, target->scsi_id, ~0, 0);
1263 
1264 	return 0;
1265 }
1266 
1267 static void srp_release_class_dev(struct class_device *class_dev)
1268 {
1269 	struct srp_host *host =
1270 		container_of(class_dev, struct srp_host, class_dev);
1271 
1272 	complete(&host->released);
1273 }
1274 
1275 static struct class srp_class = {
1276 	.name    = "infiniband_srp",
1277 	.release = srp_release_class_dev
1278 };
1279 
1280 /*
1281  * Target ports are added by writing
1282  *
1283  *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
1284  *     pkey=<P_Key>,service_id=<service ID>
1285  *
1286  * to the add_target sysfs attribute.
1287  */
1288 enum {
1289 	SRP_OPT_ERR		= 0,
1290 	SRP_OPT_ID_EXT		= 1 << 0,
1291 	SRP_OPT_IOC_GUID	= 1 << 1,
1292 	SRP_OPT_DGID		= 1 << 2,
1293 	SRP_OPT_PKEY		= 1 << 3,
1294 	SRP_OPT_SERVICE_ID	= 1 << 4,
1295 	SRP_OPT_MAX_SECT	= 1 << 5,
1296 	SRP_OPT_ALL		= (SRP_OPT_ID_EXT	|
1297 				   SRP_OPT_IOC_GUID	|
1298 				   SRP_OPT_DGID		|
1299 				   SRP_OPT_PKEY		|
1300 				   SRP_OPT_SERVICE_ID),
1301 };
1302 
1303 static match_table_t srp_opt_tokens = {
1304 	{ SRP_OPT_ID_EXT,	"id_ext=%s" 	},
1305 	{ SRP_OPT_IOC_GUID,	"ioc_guid=%s" 	},
1306 	{ SRP_OPT_DGID,		"dgid=%s" 	},
1307 	{ SRP_OPT_PKEY,		"pkey=%x" 	},
1308 	{ SRP_OPT_SERVICE_ID,	"service_id=%s" },
1309 	{ SRP_OPT_MAX_SECT,     "max_sect=%d" 	},
1310 	{ SRP_OPT_ERR,		NULL 		}
1311 };
1312 
1313 static int srp_parse_options(const char *buf, struct srp_target_port *target)
1314 {
1315 	char *options, *sep_opt;
1316 	char *p;
1317 	char dgid[3];
1318 	substring_t args[MAX_OPT_ARGS];
1319 	int opt_mask = 0;
1320 	int token;
1321 	int ret = -EINVAL;
1322 	int i;
1323 
1324 	options = kstrdup(buf, GFP_KERNEL);
1325 	if (!options)
1326 		return -ENOMEM;
1327 
1328 	sep_opt = options;
1329 	while ((p = strsep(&sep_opt, ",")) != NULL) {
1330 		if (!*p)
1331 			continue;
1332 
1333 		token = match_token(p, srp_opt_tokens, args);
1334 		opt_mask |= token;
1335 
1336 		switch (token) {
1337 		case SRP_OPT_ID_EXT:
1338 			p = match_strdup(args);
1339 			target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
1340 			kfree(p);
1341 			break;
1342 
1343 		case SRP_OPT_IOC_GUID:
1344 			p = match_strdup(args);
1345 			target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
1346 			kfree(p);
1347 			break;
1348 
1349 		case SRP_OPT_DGID:
1350 			p = match_strdup(args);
1351 			if (strlen(p) != 32) {
1352 				printk(KERN_WARNING PFX "bad dest GID parameter '%s'\n", p);
1353 				goto out;
1354 			}
1355 
1356 			for (i = 0; i < 16; ++i) {
1357 				strlcpy(dgid, p + i * 2, 3);
1358 				target->path.dgid.raw[i] = simple_strtoul(dgid, NULL, 16);
1359 			}
1360 			break;
1361 
1362 		case SRP_OPT_PKEY:
1363 			if (match_hex(args, &token)) {
1364 				printk(KERN_WARNING PFX "bad P_Key parameter '%s'\n", p);
1365 				goto out;
1366 			}
1367 			target->path.pkey = cpu_to_be16(token);
1368 			break;
1369 
1370 		case SRP_OPT_SERVICE_ID:
1371 			p = match_strdup(args);
1372 			target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
1373 			kfree(p);
1374 			break;
1375 
1376 		case SRP_OPT_MAX_SECT:
1377 			if (match_int(args, &token)) {
1378 				printk(KERN_WARNING PFX "bad max sect parameter '%s'\n", p);
1379 				goto out;
1380 			}
1381 			target->scsi_host->max_sectors = token;
1382 			break;
1383 
1384 		default:
1385 			printk(KERN_WARNING PFX "unknown parameter or missing value "
1386 			       "'%s' in target creation request\n", p);
1387 			goto out;
1388 		}
1389 	}
1390 
1391 	if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
1392 		ret = 0;
1393 	else
1394 		for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
1395 			if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
1396 			    !(srp_opt_tokens[i].token & opt_mask))
1397 				printk(KERN_WARNING PFX "target creation request is "
1398 				       "missing parameter '%s'\n",
1399 				       srp_opt_tokens[i].pattern);
1400 
1401 out:
1402 	kfree(options);
1403 	return ret;
1404 }
1405 
1406 static ssize_t srp_create_target(struct class_device *class_dev,
1407 				 const char *buf, size_t count)
1408 {
1409 	struct srp_host *host =
1410 		container_of(class_dev, struct srp_host, class_dev);
1411 	struct Scsi_Host *target_host;
1412 	struct srp_target_port *target;
1413 	int ret;
1414 	int i;
1415 
1416 	target_host = scsi_host_alloc(&srp_template,
1417 				      sizeof (struct srp_target_port));
1418 	if (!target_host)
1419 		return -ENOMEM;
1420 
1421 	target = host_to_target(target_host);
1422 	memset(target, 0, sizeof *target);
1423 
1424 	target->scsi_host  = target_host;
1425 	target->srp_host   = host;
1426 
1427 	INIT_WORK(&target->work, srp_reconnect_work, target);
1428 
1429 	for (i = 0; i < SRP_SQ_SIZE - 1; ++i)
1430 		target->req_ring[i].next = i + 1;
1431 	target->req_ring[SRP_SQ_SIZE - 1].next = -1;
1432 	INIT_LIST_HEAD(&target->req_queue);
1433 
1434 	ret = srp_parse_options(buf, target);
1435 	if (ret)
1436 		goto err;
1437 
1438 	ib_get_cached_gid(host->dev, host->port, 0, &target->path.sgid);
1439 
1440 	printk(KERN_DEBUG PFX "new target: id_ext %016llx ioc_guid %016llx pkey %04x "
1441 	       "service_id %016llx dgid %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
1442 	       (unsigned long long) be64_to_cpu(target->id_ext),
1443 	       (unsigned long long) be64_to_cpu(target->ioc_guid),
1444 	       be16_to_cpu(target->path.pkey),
1445 	       (unsigned long long) be64_to_cpu(target->service_id),
1446 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[0]),
1447 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[2]),
1448 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[4]),
1449 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[6]),
1450 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[8]),
1451 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[10]),
1452 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[12]),
1453 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[14]));
1454 
1455 	ret = srp_create_target_ib(target);
1456 	if (ret)
1457 		goto err;
1458 
1459 	target->cm_id = ib_create_cm_id(host->dev, srp_cm_handler, target);
1460 	if (IS_ERR(target->cm_id)) {
1461 		ret = PTR_ERR(target->cm_id);
1462 		goto err_free;
1463 	}
1464 
1465 	ret = srp_connect_target(target);
1466 	if (ret) {
1467 		printk(KERN_ERR PFX "Connection failed\n");
1468 		goto err_cm_id;
1469 	}
1470 
1471 	ret = srp_add_target(host, target);
1472 	if (ret)
1473 		goto err_disconnect;
1474 
1475 	return count;
1476 
1477 err_disconnect:
1478 	srp_disconnect_target(target);
1479 
1480 err_cm_id:
1481 	ib_destroy_cm_id(target->cm_id);
1482 
1483 err_free:
1484 	srp_free_target_ib(target);
1485 
1486 err:
1487 	scsi_host_put(target_host);
1488 
1489 	return ret;
1490 }
1491 
1492 static CLASS_DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
1493 
1494 static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
1495 {
1496 	struct srp_host *host =
1497 		container_of(class_dev, struct srp_host, class_dev);
1498 
1499 	return sprintf(buf, "%s\n", host->dev->name);
1500 }
1501 
1502 static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
1503 
1504 static ssize_t show_port(struct class_device *class_dev, char *buf)
1505 {
1506 	struct srp_host *host =
1507 		container_of(class_dev, struct srp_host, class_dev);
1508 
1509 	return sprintf(buf, "%d\n", host->port);
1510 }
1511 
1512 static CLASS_DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
1513 
1514 static struct srp_host *srp_add_port(struct ib_device *device,
1515 				     __be64 node_guid, u8 port)
1516 {
1517 	struct srp_host *host;
1518 
1519 	host = kzalloc(sizeof *host, GFP_KERNEL);
1520 	if (!host)
1521 		return NULL;
1522 
1523 	INIT_LIST_HEAD(&host->target_list);
1524 	init_MUTEX(&host->target_mutex);
1525 	init_completion(&host->released);
1526 	host->dev  = device;
1527 	host->port = port;
1528 
1529 	host->initiator_port_id[7] = port;
1530 	memcpy(host->initiator_port_id + 8, &node_guid, 8);
1531 
1532 	host->pd   = ib_alloc_pd(device);
1533 	if (IS_ERR(host->pd))
1534 		goto err_free;
1535 
1536 	host->mr   = ib_get_dma_mr(host->pd,
1537 				   IB_ACCESS_LOCAL_WRITE |
1538 				   IB_ACCESS_REMOTE_READ |
1539 				   IB_ACCESS_REMOTE_WRITE);
1540 	if (IS_ERR(host->mr))
1541 		goto err_pd;
1542 
1543 	host->class_dev.class = &srp_class;
1544 	host->class_dev.dev   = device->dma_device;
1545 	snprintf(host->class_dev.class_id, BUS_ID_SIZE, "srp-%s-%d",
1546 		 device->name, port);
1547 
1548 	if (class_device_register(&host->class_dev))
1549 		goto err_mr;
1550 	if (class_device_create_file(&host->class_dev, &class_device_attr_add_target))
1551 		goto err_class;
1552 	if (class_device_create_file(&host->class_dev, &class_device_attr_ibdev))
1553 		goto err_class;
1554 	if (class_device_create_file(&host->class_dev, &class_device_attr_port))
1555 		goto err_class;
1556 
1557 	return host;
1558 
1559 err_class:
1560 	class_device_unregister(&host->class_dev);
1561 
1562 err_mr:
1563 	ib_dereg_mr(host->mr);
1564 
1565 err_pd:
1566 	ib_dealloc_pd(host->pd);
1567 
1568 err_free:
1569 	kfree(host);
1570 
1571 	return NULL;
1572 }
1573 
1574 static void srp_add_one(struct ib_device *device)
1575 {
1576 	struct list_head *dev_list;
1577 	struct srp_host *host;
1578 	struct ib_device_attr *dev_attr;
1579 	int s, e, p;
1580 
1581 	dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
1582 	if (!dev_attr)
1583 		return;
1584 
1585 	if (ib_query_device(device, dev_attr)) {
1586 		printk(KERN_WARNING PFX "Couldn't query node GUID for %s.\n",
1587 		       device->name);
1588 		goto out;
1589 	}
1590 
1591 	dev_list = kmalloc(sizeof *dev_list, GFP_KERNEL);
1592 	if (!dev_list)
1593 		goto out;
1594 
1595 	INIT_LIST_HEAD(dev_list);
1596 
1597 	if (device->node_type == IB_NODE_SWITCH) {
1598 		s = 0;
1599 		e = 0;
1600 	} else {
1601 		s = 1;
1602 		e = device->phys_port_cnt;
1603 	}
1604 
1605 	for (p = s; p <= e; ++p) {
1606 		host = srp_add_port(device, dev_attr->node_guid, p);
1607 		if (host)
1608 			list_add_tail(&host->list, dev_list);
1609 	}
1610 
1611 	ib_set_client_data(device, &srp_client, dev_list);
1612 
1613 out:
1614 	kfree(dev_attr);
1615 }
1616 
1617 static void srp_remove_one(struct ib_device *device)
1618 {
1619 	struct list_head *dev_list;
1620 	struct srp_host *host, *tmp_host;
1621 	LIST_HEAD(target_list);
1622 	struct srp_target_port *target, *tmp_target;
1623 	unsigned long flags;
1624 
1625 	dev_list = ib_get_client_data(device, &srp_client);
1626 
1627 	list_for_each_entry_safe(host, tmp_host, dev_list, list) {
1628 		class_device_unregister(&host->class_dev);
1629 		/*
1630 		 * Wait for the sysfs entry to go away, so that no new
1631 		 * target ports can be created.
1632 		 */
1633 		wait_for_completion(&host->released);
1634 
1635 		/*
1636 		 * Mark all target ports as removed, so we stop queueing
1637 		 * commands and don't try to reconnect.
1638 		 */
1639 		down(&host->target_mutex);
1640 		list_for_each_entry_safe(target, tmp_target,
1641 					 &host->target_list, list) {
1642 			spin_lock_irqsave(target->scsi_host->host_lock, flags);
1643 			if (target->state != SRP_TARGET_REMOVED)
1644 				target->state = SRP_TARGET_REMOVED;
1645 			spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
1646 		}
1647 		up(&host->target_mutex);
1648 
1649 		/*
1650 		 * Wait for any reconnection tasks that may have
1651 		 * started before we marked our target ports as
1652 		 * removed, and any target port removal tasks.
1653 		 */
1654 		flush_scheduled_work();
1655 
1656 		list_for_each_entry_safe(target, tmp_target,
1657 					 &host->target_list, list) {
1658 			scsi_remove_host(target->scsi_host);
1659 			srp_disconnect_target(target);
1660 			ib_destroy_cm_id(target->cm_id);
1661 			srp_free_target_ib(target);
1662 			scsi_host_put(target->scsi_host);
1663 		}
1664 
1665 		ib_dereg_mr(host->mr);
1666 		ib_dealloc_pd(host->pd);
1667 		kfree(host);
1668 	}
1669 
1670 	kfree(dev_list);
1671 }
1672 
1673 static int __init srp_init_module(void)
1674 {
1675 	int ret;
1676 
1677 	ret = class_register(&srp_class);
1678 	if (ret) {
1679 		printk(KERN_ERR PFX "couldn't register class infiniband_srp\n");
1680 		return ret;
1681 	}
1682 
1683 	ret = ib_register_client(&srp_client);
1684 	if (ret) {
1685 		printk(KERN_ERR PFX "couldn't register IB client\n");
1686 		class_unregister(&srp_class);
1687 		return ret;
1688 	}
1689 
1690 	return 0;
1691 }
1692 
1693 static void __exit srp_cleanup_module(void)
1694 {
1695 	ib_unregister_client(&srp_client);
1696 	class_unregister(&srp_class);
1697 }
1698 
1699 module_init(srp_init_module);
1700 module_exit(srp_cleanup_module);
1701