xref: /linux/drivers/infiniband/ulp/srp/ib_srp.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
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/module.h>
36 #include <linux/init.h>
37 #include <linux/slab.h>
38 #include <linux/err.h>
39 #include <linux/string.h>
40 #include <linux/parser.h>
41 #include <linux/random.h>
42 
43 #include <asm/atomic.h>
44 
45 #include <scsi/scsi.h>
46 #include <scsi/scsi_device.h>
47 #include <scsi/scsi_dbg.h>
48 #include <scsi/srp.h>
49 
50 #include <rdma/ib_cache.h>
51 
52 #include "ib_srp.h"
53 
54 #define DRV_NAME	"ib_srp"
55 #define PFX		DRV_NAME ": "
56 #define DRV_VERSION	"0.2"
57 #define DRV_RELDATE	"November 1, 2005"
58 
59 MODULE_AUTHOR("Roland Dreier");
60 MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol initiator "
61 		   "v" DRV_VERSION " (" DRV_RELDATE ")");
62 MODULE_LICENSE("Dual BSD/GPL");
63 
64 static int topspin_workarounds = 1;
65 
66 module_param(topspin_workarounds, int, 0444);
67 MODULE_PARM_DESC(topspin_workarounds,
68 		 "Enable workarounds for Topspin/Cisco SRP target bugs if != 0");
69 
70 static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
71 
72 static void srp_add_one(struct ib_device *device);
73 static void srp_remove_one(struct ib_device *device);
74 static void srp_completion(struct ib_cq *cq, void *target_ptr);
75 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);
76 
77 static struct ib_client srp_client = {
78 	.name   = "srp",
79 	.add    = srp_add_one,
80 	.remove = srp_remove_one
81 };
82 
83 static inline struct srp_target_port *host_to_target(struct Scsi_Host *host)
84 {
85 	return (struct srp_target_port *) host->hostdata;
86 }
87 
88 static const char *srp_target_info(struct Scsi_Host *host)
89 {
90 	return host_to_target(host)->target_name;
91 }
92 
93 static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
94 				   gfp_t gfp_mask,
95 				   enum dma_data_direction direction)
96 {
97 	struct srp_iu *iu;
98 
99 	iu = kmalloc(sizeof *iu, gfp_mask);
100 	if (!iu)
101 		goto out;
102 
103 	iu->buf = kzalloc(size, gfp_mask);
104 	if (!iu->buf)
105 		goto out_free_iu;
106 
107 	iu->dma = dma_map_single(host->dev->dma_device, iu->buf, size, direction);
108 	if (dma_mapping_error(iu->dma))
109 		goto out_free_buf;
110 
111 	iu->size      = size;
112 	iu->direction = direction;
113 
114 	return iu;
115 
116 out_free_buf:
117 	kfree(iu->buf);
118 out_free_iu:
119 	kfree(iu);
120 out:
121 	return NULL;
122 }
123 
124 static void srp_free_iu(struct srp_host *host, struct srp_iu *iu)
125 {
126 	if (!iu)
127 		return;
128 
129 	dma_unmap_single(host->dev->dma_device, iu->dma, iu->size, iu->direction);
130 	kfree(iu->buf);
131 	kfree(iu);
132 }
133 
134 static void srp_qp_event(struct ib_event *event, void *context)
135 {
136 	printk(KERN_ERR PFX "QP event %d\n", event->event);
137 }
138 
139 static int srp_init_qp(struct srp_target_port *target,
140 		       struct ib_qp *qp)
141 {
142 	struct ib_qp_attr *attr;
143 	int ret;
144 
145 	attr = kmalloc(sizeof *attr, GFP_KERNEL);
146 	if (!attr)
147 		return -ENOMEM;
148 
149 	ret = ib_find_cached_pkey(target->srp_host->dev,
150 				  target->srp_host->port,
151 				  be16_to_cpu(target->path.pkey),
152 				  &attr->pkey_index);
153 	if (ret)
154 		goto out;
155 
156 	attr->qp_state        = IB_QPS_INIT;
157 	attr->qp_access_flags = (IB_ACCESS_REMOTE_READ |
158 				    IB_ACCESS_REMOTE_WRITE);
159 	attr->port_num        = target->srp_host->port;
160 
161 	ret = ib_modify_qp(qp, attr,
162 			   IB_QP_STATE		|
163 			   IB_QP_PKEY_INDEX	|
164 			   IB_QP_ACCESS_FLAGS	|
165 			   IB_QP_PORT);
166 
167 out:
168 	kfree(attr);
169 	return ret;
170 }
171 
172 static int srp_create_target_ib(struct srp_target_port *target)
173 {
174 	struct ib_qp_init_attr *init_attr;
175 	int ret;
176 
177 	init_attr = kzalloc(sizeof *init_attr, GFP_KERNEL);
178 	if (!init_attr)
179 		return -ENOMEM;
180 
181 	target->cq = ib_create_cq(target->srp_host->dev, srp_completion,
182 				  NULL, target, SRP_CQ_SIZE);
183 	if (IS_ERR(target->cq)) {
184 		ret = PTR_ERR(target->cq);
185 		goto out;
186 	}
187 
188 	ib_req_notify_cq(target->cq, IB_CQ_NEXT_COMP);
189 
190 	init_attr->event_handler       = srp_qp_event;
191 	init_attr->cap.max_send_wr     = SRP_SQ_SIZE;
192 	init_attr->cap.max_recv_wr     = SRP_RQ_SIZE;
193 	init_attr->cap.max_recv_sge    = 1;
194 	init_attr->cap.max_send_sge    = 1;
195 	init_attr->sq_sig_type         = IB_SIGNAL_ALL_WR;
196 	init_attr->qp_type             = IB_QPT_RC;
197 	init_attr->send_cq             = target->cq;
198 	init_attr->recv_cq             = target->cq;
199 
200 	target->qp = ib_create_qp(target->srp_host->pd, init_attr);
201 	if (IS_ERR(target->qp)) {
202 		ret = PTR_ERR(target->qp);
203 		ib_destroy_cq(target->cq);
204 		goto out;
205 	}
206 
207 	ret = srp_init_qp(target, target->qp);
208 	if (ret) {
209 		ib_destroy_qp(target->qp);
210 		ib_destroy_cq(target->cq);
211 		goto out;
212 	}
213 
214 out:
215 	kfree(init_attr);
216 	return ret;
217 }
218 
219 static void srp_free_target_ib(struct srp_target_port *target)
220 {
221 	int i;
222 
223 	ib_destroy_qp(target->qp);
224 	ib_destroy_cq(target->cq);
225 
226 	for (i = 0; i < SRP_RQ_SIZE; ++i)
227 		srp_free_iu(target->srp_host, target->rx_ring[i]);
228 	for (i = 0; i < SRP_SQ_SIZE + 1; ++i)
229 		srp_free_iu(target->srp_host, target->tx_ring[i]);
230 }
231 
232 static void srp_path_rec_completion(int status,
233 				    struct ib_sa_path_rec *pathrec,
234 				    void *target_ptr)
235 {
236 	struct srp_target_port *target = target_ptr;
237 
238 	target->status = status;
239 	if (status)
240 		printk(KERN_ERR PFX "Got failed path rec status %d\n", status);
241 	else
242 		target->path = *pathrec;
243 	complete(&target->done);
244 }
245 
246 static int srp_lookup_path(struct srp_target_port *target)
247 {
248 	target->path.numb_path = 1;
249 
250 	init_completion(&target->done);
251 
252 	target->path_query_id = ib_sa_path_rec_get(target->srp_host->dev,
253 						   target->srp_host->port,
254 						   &target->path,
255 						   IB_SA_PATH_REC_DGID		|
256 						   IB_SA_PATH_REC_SGID		|
257 						   IB_SA_PATH_REC_NUMB_PATH	|
258 						   IB_SA_PATH_REC_PKEY,
259 						   SRP_PATH_REC_TIMEOUT_MS,
260 						   GFP_KERNEL,
261 						   srp_path_rec_completion,
262 						   target, &target->path_query);
263 	if (target->path_query_id < 0)
264 		return target->path_query_id;
265 
266 	wait_for_completion(&target->done);
267 
268 	if (target->status < 0)
269 		printk(KERN_WARNING PFX "Path record query failed\n");
270 
271 	return target->status;
272 }
273 
274 static int srp_send_req(struct srp_target_port *target)
275 {
276 	struct {
277 		struct ib_cm_req_param param;
278 		struct srp_login_req   priv;
279 	} *req = NULL;
280 	int status;
281 
282 	req = kzalloc(sizeof *req, GFP_KERNEL);
283 	if (!req)
284 		return -ENOMEM;
285 
286 	req->param.primary_path 	      = &target->path;
287 	req->param.alternate_path 	      = NULL;
288 	req->param.service_id 		      = target->service_id;
289 	req->param.qp_num 		      = target->qp->qp_num;
290 	req->param.qp_type 		      = target->qp->qp_type;
291 	req->param.private_data 	      = &req->priv;
292 	req->param.private_data_len 	      = sizeof req->priv;
293 	req->param.flow_control 	      = 1;
294 
295 	get_random_bytes(&req->param.starting_psn, 4);
296 	req->param.starting_psn 	     &= 0xffffff;
297 
298 	/*
299 	 * Pick some arbitrary defaults here; we could make these
300 	 * module parameters if anyone cared about setting them.
301 	 */
302 	req->param.responder_resources	      = 4;
303 	req->param.remote_cm_response_timeout = 20;
304 	req->param.local_cm_response_timeout  = 20;
305 	req->param.retry_count 		      = 7;
306 	req->param.rnr_retry_count 	      = 7;
307 	req->param.max_cm_retries 	      = 15;
308 
309 	req->priv.opcode     	= SRP_LOGIN_REQ;
310 	req->priv.tag        	= 0;
311 	req->priv.req_it_iu_len = cpu_to_be32(SRP_MAX_IU_LEN);
312 	req->priv.req_buf_fmt 	= cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
313 					      SRP_BUF_FORMAT_INDIRECT);
314 	memcpy(req->priv.initiator_port_id, target->srp_host->initiator_port_id, 16);
315 	/*
316 	 * Topspin/Cisco SRP targets will reject our login unless we
317 	 * zero out the first 8 bytes of our initiator port ID.  The
318 	 * second 8 bytes must be our local node GUID, but we always
319 	 * use that anyway.
320 	 */
321 	if (topspin_workarounds && !memcmp(&target->ioc_guid, topspin_oui, 3)) {
322 		printk(KERN_DEBUG PFX "Topspin/Cisco initiator port ID workaround "
323 		       "activated for target GUID %016llx\n",
324 		       (unsigned long long) be64_to_cpu(target->ioc_guid));
325 		memset(req->priv.initiator_port_id, 0, 8);
326 	}
327 	memcpy(req->priv.target_port_id,     &target->id_ext, 8);
328 	memcpy(req->priv.target_port_id + 8, &target->ioc_guid, 8);
329 
330 	status = ib_send_cm_req(target->cm_id, &req->param);
331 
332 	kfree(req);
333 
334 	return status;
335 }
336 
337 static void srp_disconnect_target(struct srp_target_port *target)
338 {
339 	/* XXX should send SRP_I_LOGOUT request */
340 
341 	init_completion(&target->done);
342 	ib_send_cm_dreq(target->cm_id, NULL, 0);
343 	wait_for_completion(&target->done);
344 }
345 
346 static void srp_remove_work(void *target_ptr)
347 {
348 	struct srp_target_port *target = target_ptr;
349 
350 	spin_lock_irq(target->scsi_host->host_lock);
351 	if (target->state != SRP_TARGET_DEAD) {
352 		spin_unlock_irq(target->scsi_host->host_lock);
353 		scsi_host_put(target->scsi_host);
354 		return;
355 	}
356 	target->state = SRP_TARGET_REMOVED;
357 	spin_unlock_irq(target->scsi_host->host_lock);
358 
359 	down(&target->srp_host->target_mutex);
360 	list_del(&target->list);
361 	up(&target->srp_host->target_mutex);
362 
363 	scsi_remove_host(target->scsi_host);
364 	ib_destroy_cm_id(target->cm_id);
365 	srp_free_target_ib(target);
366 	scsi_host_put(target->scsi_host);
367 	/* And another put to really free the target port... */
368 	scsi_host_put(target->scsi_host);
369 }
370 
371 static int srp_connect_target(struct srp_target_port *target)
372 {
373 	int ret;
374 
375 	ret = srp_lookup_path(target);
376 	if (ret)
377 		return ret;
378 
379 	while (1) {
380 		init_completion(&target->done);
381 		ret = srp_send_req(target);
382 		if (ret)
383 			return ret;
384 		wait_for_completion(&target->done);
385 
386 		/*
387 		 * The CM event handling code will set status to
388 		 * SRP_PORT_REDIRECT if we get a port redirect REJ
389 		 * back, or SRP_DLID_REDIRECT if we get a lid/qp
390 		 * redirect REJ back.
391 		 */
392 		switch (target->status) {
393 		case 0:
394 			return 0;
395 
396 		case SRP_PORT_REDIRECT:
397 			ret = srp_lookup_path(target);
398 			if (ret)
399 				return ret;
400 			break;
401 
402 		case SRP_DLID_REDIRECT:
403 			break;
404 
405 		default:
406 			return target->status;
407 		}
408 	}
409 }
410 
411 static int srp_reconnect_target(struct srp_target_port *target)
412 {
413 	struct ib_cm_id *new_cm_id;
414 	struct ib_qp_attr qp_attr;
415 	struct srp_request *req;
416 	struct ib_wc wc;
417 	int ret;
418 	int i;
419 
420 	spin_lock_irq(target->scsi_host->host_lock);
421 	if (target->state != SRP_TARGET_LIVE) {
422 		spin_unlock_irq(target->scsi_host->host_lock);
423 		return -EAGAIN;
424 	}
425 	target->state = SRP_TARGET_CONNECTING;
426 	spin_unlock_irq(target->scsi_host->host_lock);
427 
428 	srp_disconnect_target(target);
429 	/*
430 	 * Now get a new local CM ID so that we avoid confusing the
431 	 * target in case things are really fouled up.
432 	 */
433 	new_cm_id = ib_create_cm_id(target->srp_host->dev,
434 				    srp_cm_handler, target);
435 	if (IS_ERR(new_cm_id)) {
436 		ret = PTR_ERR(new_cm_id);
437 		goto err;
438 	}
439 	ib_destroy_cm_id(target->cm_id);
440 	target->cm_id = new_cm_id;
441 
442 	qp_attr.qp_state = IB_QPS_RESET;
443 	ret = ib_modify_qp(target->qp, &qp_attr, IB_QP_STATE);
444 	if (ret)
445 		goto err;
446 
447 	ret = srp_init_qp(target, target->qp);
448 	if (ret)
449 		goto err;
450 
451 	while (ib_poll_cq(target->cq, 1, &wc) > 0)
452 		; /* nothing */
453 
454 	list_for_each_entry(req, &target->req_queue, list) {
455 		req->scmnd->result = DID_RESET << 16;
456 		req->scmnd->scsi_done(req->scmnd);
457 	}
458 
459 	target->rx_head	 = 0;
460 	target->tx_head	 = 0;
461 	target->tx_tail  = 0;
462 	target->req_head = 0;
463 	for (i = 0; i < SRP_SQ_SIZE - 1; ++i)
464 		target->req_ring[i].next = i + 1;
465 	target->req_ring[SRP_SQ_SIZE - 1].next = -1;
466 	INIT_LIST_HEAD(&target->req_queue);
467 
468 	ret = srp_connect_target(target);
469 	if (ret)
470 		goto err;
471 
472 	spin_lock_irq(target->scsi_host->host_lock);
473 	if (target->state == SRP_TARGET_CONNECTING) {
474 		ret = 0;
475 		target->state = SRP_TARGET_LIVE;
476 	} else
477 		ret = -EAGAIN;
478 	spin_unlock_irq(target->scsi_host->host_lock);
479 
480 	return ret;
481 
482 err:
483 	printk(KERN_ERR PFX "reconnect failed (%d), removing target port.\n", ret);
484 
485 	/*
486 	 * We couldn't reconnect, so kill our target port off.
487 	 * However, we have to defer the real removal because we might
488 	 * be in the context of the SCSI error handler now, which
489 	 * would deadlock if we call scsi_remove_host().
490 	 */
491 	spin_lock_irq(target->scsi_host->host_lock);
492 	if (target->state == SRP_TARGET_CONNECTING) {
493 		target->state = SRP_TARGET_DEAD;
494 		INIT_WORK(&target->work, srp_remove_work, target);
495 		schedule_work(&target->work);
496 	}
497 	spin_unlock_irq(target->scsi_host->host_lock);
498 
499 	return ret;
500 }
501 
502 static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
503 			struct srp_request *req)
504 {
505 	struct srp_cmd *cmd = req->cmd->buf;
506 	int len;
507 	u8 fmt;
508 
509 	if (!scmnd->request_buffer || scmnd->sc_data_direction == DMA_NONE)
510 		return sizeof (struct srp_cmd);
511 
512 	if (scmnd->sc_data_direction != DMA_FROM_DEVICE &&
513 	    scmnd->sc_data_direction != DMA_TO_DEVICE) {
514 		printk(KERN_WARNING PFX "Unhandled data direction %d\n",
515 		       scmnd->sc_data_direction);
516 		return -EINVAL;
517 	}
518 
519 	if (scmnd->use_sg) {
520 		struct scatterlist *scat = scmnd->request_buffer;
521 		int n;
522 		int i;
523 
524 		n = dma_map_sg(target->srp_host->dev->dma_device,
525 			       scat, scmnd->use_sg, scmnd->sc_data_direction);
526 
527 		if (n == 1) {
528 			struct srp_direct_buf *buf = (void *) cmd->add_data;
529 
530 			fmt = SRP_DATA_DESC_DIRECT;
531 
532 			buf->va  = cpu_to_be64(sg_dma_address(scat));
533 			buf->key = cpu_to_be32(target->srp_host->mr->rkey);
534 			buf->len = cpu_to_be32(sg_dma_len(scat));
535 
536 			len = sizeof (struct srp_cmd) +
537 				sizeof (struct srp_direct_buf);
538 		} else {
539 			struct srp_indirect_buf *buf = (void *) cmd->add_data;
540 			u32 datalen = 0;
541 
542 			fmt = SRP_DATA_DESC_INDIRECT;
543 
544 			if (scmnd->sc_data_direction == DMA_TO_DEVICE)
545 				cmd->data_out_desc_cnt = n;
546 			else
547 				cmd->data_in_desc_cnt = n;
548 
549 			buf->table_desc.va  = cpu_to_be64(req->cmd->dma +
550 							  sizeof *cmd +
551 							  sizeof *buf);
552 			buf->table_desc.key =
553 				cpu_to_be32(target->srp_host->mr->rkey);
554 			buf->table_desc.len =
555 				cpu_to_be32(n * sizeof (struct srp_direct_buf));
556 
557 			for (i = 0; i < n; ++i) {
558 				buf->desc_list[i].va  = cpu_to_be64(sg_dma_address(&scat[i]));
559 				buf->desc_list[i].key =
560 					cpu_to_be32(target->srp_host->mr->rkey);
561 				buf->desc_list[i].len = cpu_to_be32(sg_dma_len(&scat[i]));
562 
563 				datalen += sg_dma_len(&scat[i]);
564 			}
565 
566 			buf->len = cpu_to_be32(datalen);
567 
568 			len = sizeof (struct srp_cmd) +
569 				sizeof (struct srp_indirect_buf) +
570 				n * sizeof (struct srp_direct_buf);
571 		}
572 	} else {
573 		struct srp_direct_buf *buf = (void *) cmd->add_data;
574 		dma_addr_t dma;
575 
576 		dma = dma_map_single(target->srp_host->dev->dma_device,
577 				     scmnd->request_buffer, scmnd->request_bufflen,
578 				     scmnd->sc_data_direction);
579 		if (dma_mapping_error(dma)) {
580 			printk(KERN_WARNING PFX "unable to map %p/%d (dir %d)\n",
581 			       scmnd->request_buffer, (int) scmnd->request_bufflen,
582 			       scmnd->sc_data_direction);
583 			return -EINVAL;
584 		}
585 
586 		pci_unmap_addr_set(req, direct_mapping, dma);
587 
588 		buf->va  = cpu_to_be64(dma);
589 		buf->key = cpu_to_be32(target->srp_host->mr->rkey);
590 		buf->len = cpu_to_be32(scmnd->request_bufflen);
591 
592 		fmt = SRP_DATA_DESC_DIRECT;
593 
594 		len = sizeof (struct srp_cmd) + sizeof (struct srp_direct_buf);
595 	}
596 
597 	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
598 		cmd->buf_fmt = fmt << 4;
599 	else
600 		cmd->buf_fmt = fmt;
601 
602 
603 	return len;
604 }
605 
606 static void srp_unmap_data(struct scsi_cmnd *scmnd,
607 			   struct srp_target_port *target,
608 			   struct srp_request *req)
609 {
610 	if (!scmnd->request_buffer ||
611 	    (scmnd->sc_data_direction != DMA_TO_DEVICE &&
612 	     scmnd->sc_data_direction != DMA_FROM_DEVICE))
613 	    return;
614 
615 	if (scmnd->use_sg)
616 		dma_unmap_sg(target->srp_host->dev->dma_device,
617 			     (struct scatterlist *) scmnd->request_buffer,
618 			     scmnd->use_sg, scmnd->sc_data_direction);
619 	else
620 		dma_unmap_single(target->srp_host->dev->dma_device,
621 				 pci_unmap_addr(req, direct_mapping),
622 				 scmnd->request_bufflen,
623 				 scmnd->sc_data_direction);
624 }
625 
626 static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
627 {
628 	struct srp_request *req;
629 	struct scsi_cmnd *scmnd;
630 	unsigned long flags;
631 	s32 delta;
632 
633 	delta = (s32) be32_to_cpu(rsp->req_lim_delta);
634 
635 	spin_lock_irqsave(target->scsi_host->host_lock, flags);
636 
637 	target->req_lim += delta;
638 
639 	req = &target->req_ring[rsp->tag & ~SRP_TAG_TSK_MGMT];
640 
641 	if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
642 		if (be32_to_cpu(rsp->resp_data_len) < 4)
643 			req->tsk_status = -1;
644 		else
645 			req->tsk_status = rsp->data[3];
646 		complete(&req->done);
647 	} else {
648 		scmnd 	      = req->scmnd;
649 		if (!scmnd)
650 			printk(KERN_ERR "Null scmnd for RSP w/tag %016llx\n",
651 			       (unsigned long long) rsp->tag);
652 		scmnd->result = rsp->status;
653 
654 		if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
655 			memcpy(scmnd->sense_buffer, rsp->data +
656 			       be32_to_cpu(rsp->resp_data_len),
657 			       min_t(int, be32_to_cpu(rsp->sense_data_len),
658 				     SCSI_SENSE_BUFFERSIZE));
659 		}
660 
661 		if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
662 			scmnd->resid = be32_to_cpu(rsp->data_out_res_cnt);
663 		else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
664 			scmnd->resid = be32_to_cpu(rsp->data_in_res_cnt);
665 
666 		srp_unmap_data(scmnd, target, req);
667 
668 		if (!req->tsk_mgmt) {
669 			req->scmnd = NULL;
670 			scmnd->host_scribble = (void *) -1L;
671 			scmnd->scsi_done(scmnd);
672 
673 			list_del(&req->list);
674 			req->next = target->req_head;
675 			target->req_head = rsp->tag & ~SRP_TAG_TSK_MGMT;
676 		} else
677 			req->cmd_done = 1;
678 	}
679 
680 	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
681 }
682 
683 static void srp_reconnect_work(void *target_ptr)
684 {
685 	struct srp_target_port *target = target_ptr;
686 
687 	srp_reconnect_target(target);
688 }
689 
690 static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
691 {
692 	struct srp_iu *iu;
693 	u8 opcode;
694 
695 	iu = target->rx_ring[wc->wr_id & ~SRP_OP_RECV];
696 
697 	dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
698 				target->max_ti_iu_len, DMA_FROM_DEVICE);
699 
700 	opcode = *(u8 *) iu->buf;
701 
702 	if (0) {
703 		int i;
704 
705 		printk(KERN_ERR PFX "recv completion, opcode 0x%02x\n", opcode);
706 
707 		for (i = 0; i < wc->byte_len; ++i) {
708 			if (i % 8 == 0)
709 				printk(KERN_ERR "  [%02x] ", i);
710 			printk(" %02x", ((u8 *) iu->buf)[i]);
711 			if ((i + 1) % 8 == 0)
712 				printk("\n");
713 		}
714 
715 		if (wc->byte_len % 8)
716 			printk("\n");
717 	}
718 
719 	switch (opcode) {
720 	case SRP_RSP:
721 		srp_process_rsp(target, iu->buf);
722 		break;
723 
724 	case SRP_T_LOGOUT:
725 		/* XXX Handle target logout */
726 		printk(KERN_WARNING PFX "Got target logout request\n");
727 		break;
728 
729 	default:
730 		printk(KERN_WARNING PFX "Unhandled SRP opcode 0x%02x\n", opcode);
731 		break;
732 	}
733 
734 	dma_sync_single_for_device(target->srp_host->dev->dma_device, iu->dma,
735 				   target->max_ti_iu_len, DMA_FROM_DEVICE);
736 }
737 
738 static void srp_completion(struct ib_cq *cq, void *target_ptr)
739 {
740 	struct srp_target_port *target = target_ptr;
741 	struct ib_wc wc;
742 	unsigned long flags;
743 
744 	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
745 	while (ib_poll_cq(cq, 1, &wc) > 0) {
746 		if (wc.status) {
747 			printk(KERN_ERR PFX "failed %s status %d\n",
748 			       wc.wr_id & SRP_OP_RECV ? "receive" : "send",
749 			       wc.status);
750 			spin_lock_irqsave(target->scsi_host->host_lock, flags);
751 			if (target->state == SRP_TARGET_LIVE)
752 				schedule_work(&target->work);
753 			spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
754 			break;
755 		}
756 
757 		if (wc.wr_id & SRP_OP_RECV)
758 			srp_handle_recv(target, &wc);
759 		else
760 			++target->tx_tail;
761 	}
762 }
763 
764 static int __srp_post_recv(struct srp_target_port *target)
765 {
766 	struct srp_iu *iu;
767 	struct ib_sge list;
768 	struct ib_recv_wr wr, *bad_wr;
769 	unsigned int next;
770 	int ret;
771 
772 	next 	 = target->rx_head & (SRP_RQ_SIZE - 1);
773 	wr.wr_id = next | SRP_OP_RECV;
774 	iu 	 = target->rx_ring[next];
775 
776 	list.addr   = iu->dma;
777 	list.length = iu->size;
778 	list.lkey   = target->srp_host->mr->lkey;
779 
780 	wr.next     = NULL;
781 	wr.sg_list  = &list;
782 	wr.num_sge  = 1;
783 
784 	ret = ib_post_recv(target->qp, &wr, &bad_wr);
785 	if (!ret)
786 		++target->rx_head;
787 
788 	return ret;
789 }
790 
791 static int srp_post_recv(struct srp_target_port *target)
792 {
793 	unsigned long flags;
794 	int ret;
795 
796 	spin_lock_irqsave(target->scsi_host->host_lock, flags);
797 	ret = __srp_post_recv(target);
798 	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
799 
800 	return ret;
801 }
802 
803 /*
804  * Must be called with target->scsi_host->host_lock held to protect
805  * req_lim and tx_head.  Lock cannot be dropped between call here and
806  * call to __srp_post_send().
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 	if (unlikely(target->req_lim < 1)) {
814 		if (printk_ratelimit())
815 			printk(KERN_DEBUG PFX "Target has req_lim %d\n",
816 			       target->req_lim);
817 		return NULL;
818 	}
819 
820 	return target->tx_ring[target->tx_head & SRP_SQ_SIZE];
821 }
822 
823 /*
824  * Must be called with target->scsi_host->host_lock held to protect
825  * req_lim and tx_head.
826  */
827 static int __srp_post_send(struct srp_target_port *target,
828 			   struct srp_iu *iu, int len)
829 {
830 	struct ib_sge list;
831 	struct ib_send_wr wr, *bad_wr;
832 	int ret = 0;
833 
834 	list.addr   = iu->dma;
835 	list.length = len;
836 	list.lkey   = target->srp_host->mr->lkey;
837 
838 	wr.next       = NULL;
839 	wr.wr_id      = target->tx_head & SRP_SQ_SIZE;
840 	wr.sg_list    = &list;
841 	wr.num_sge    = 1;
842 	wr.opcode     = IB_WR_SEND;
843 	wr.send_flags = IB_SEND_SIGNALED;
844 
845 	ret = ib_post_send(target->qp, &wr, &bad_wr);
846 
847 	if (!ret) {
848 		++target->tx_head;
849 		--target->req_lim;
850 	}
851 
852 	return ret;
853 }
854 
855 static int srp_queuecommand(struct scsi_cmnd *scmnd,
856 			    void (*done)(struct scsi_cmnd *))
857 {
858 	struct srp_target_port *target = host_to_target(scmnd->device->host);
859 	struct srp_request *req;
860 	struct srp_iu *iu;
861 	struct srp_cmd *cmd;
862 	long req_index;
863 	int len;
864 
865 	if (target->state == SRP_TARGET_CONNECTING)
866 		goto err;
867 
868 	if (target->state == SRP_TARGET_DEAD ||
869 	    target->state == SRP_TARGET_REMOVED) {
870 		scmnd->result = DID_BAD_TARGET << 16;
871 		done(scmnd);
872 		return 0;
873 	}
874 
875 	iu = __srp_get_tx_iu(target);
876 	if (!iu)
877 		goto err;
878 
879 	dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
880 				SRP_MAX_IU_LEN, DMA_TO_DEVICE);
881 
882 	req_index = target->req_head;
883 
884 	scmnd->scsi_done     = done;
885 	scmnd->result        = 0;
886 	scmnd->host_scribble = (void *) req_index;
887 
888 	cmd = iu->buf;
889 	memset(cmd, 0, sizeof *cmd);
890 
891 	cmd->opcode = SRP_CMD;
892 	cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
893 	cmd->tag    = req_index;
894 	memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
895 
896 	req = &target->req_ring[req_index];
897 
898 	req->scmnd    = scmnd;
899 	req->cmd      = iu;
900 	req->cmd_done = 0;
901 	req->tsk_mgmt = NULL;
902 
903 	len = srp_map_data(scmnd, target, req);
904 	if (len < 0) {
905 		printk(KERN_ERR PFX "Failed to map data\n");
906 		goto err;
907 	}
908 
909 	if (__srp_post_recv(target)) {
910 		printk(KERN_ERR PFX "Recv failed\n");
911 		goto err_unmap;
912 	}
913 
914 	dma_sync_single_for_device(target->srp_host->dev->dma_device, iu->dma,
915 				   SRP_MAX_IU_LEN, DMA_TO_DEVICE);
916 
917 	if (__srp_post_send(target, iu, len)) {
918 		printk(KERN_ERR PFX "Send failed\n");
919 		goto err_unmap;
920 	}
921 
922 	target->req_head = req->next;
923 	list_add_tail(&req->list, &target->req_queue);
924 
925 	return 0;
926 
927 err_unmap:
928 	srp_unmap_data(scmnd, target, req);
929 
930 err:
931 	return SCSI_MLQUEUE_HOST_BUSY;
932 }
933 
934 static int srp_alloc_iu_bufs(struct srp_target_port *target)
935 {
936 	int i;
937 
938 	for (i = 0; i < SRP_RQ_SIZE; ++i) {
939 		target->rx_ring[i] = srp_alloc_iu(target->srp_host,
940 						  target->max_ti_iu_len,
941 						  GFP_KERNEL, DMA_FROM_DEVICE);
942 		if (!target->rx_ring[i])
943 			goto err;
944 	}
945 
946 	for (i = 0; i < SRP_SQ_SIZE + 1; ++i) {
947 		target->tx_ring[i] = srp_alloc_iu(target->srp_host,
948 						  SRP_MAX_IU_LEN,
949 						  GFP_KERNEL, DMA_TO_DEVICE);
950 		if (!target->tx_ring[i])
951 			goto err;
952 	}
953 
954 	return 0;
955 
956 err:
957 	for (i = 0; i < SRP_RQ_SIZE; ++i) {
958 		srp_free_iu(target->srp_host, target->rx_ring[i]);
959 		target->rx_ring[i] = NULL;
960 	}
961 
962 	for (i = 0; i < SRP_SQ_SIZE + 1; ++i) {
963 		srp_free_iu(target->srp_host, target->tx_ring[i]);
964 		target->tx_ring[i] = NULL;
965 	}
966 
967 	return -ENOMEM;
968 }
969 
970 static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
971 			       struct ib_cm_event *event,
972 			       struct srp_target_port *target)
973 {
974 	struct ib_class_port_info *cpi;
975 	int opcode;
976 
977 	switch (event->param.rej_rcvd.reason) {
978 	case IB_CM_REJ_PORT_CM_REDIRECT:
979 		cpi = event->param.rej_rcvd.ari;
980 		target->path.dlid = cpi->redirect_lid;
981 		target->path.pkey = cpi->redirect_pkey;
982 		cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
983 		memcpy(target->path.dgid.raw, cpi->redirect_gid, 16);
984 
985 		target->status = target->path.dlid ?
986 			SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
987 		break;
988 
989 	case IB_CM_REJ_PORT_REDIRECT:
990 		if (topspin_workarounds &&
991 		    !memcmp(&target->ioc_guid, topspin_oui, 3)) {
992 			/*
993 			 * Topspin/Cisco SRP gateways incorrectly send
994 			 * reject reason code 25 when they mean 24
995 			 * (port redirect).
996 			 */
997 			memcpy(target->path.dgid.raw,
998 			       event->param.rej_rcvd.ari, 16);
999 
1000 			printk(KERN_DEBUG PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
1001 			       (unsigned long long) be64_to_cpu(target->path.dgid.global.subnet_prefix),
1002 			       (unsigned long long) be64_to_cpu(target->path.dgid.global.interface_id));
1003 
1004 			target->status = SRP_PORT_REDIRECT;
1005 		} else {
1006 			printk(KERN_WARNING "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
1007 			target->status = -ECONNRESET;
1008 		}
1009 		break;
1010 
1011 	case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
1012 		printk(KERN_WARNING "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
1013 		target->status = -ECONNRESET;
1014 		break;
1015 
1016 	case IB_CM_REJ_CONSUMER_DEFINED:
1017 		opcode = *(u8 *) event->private_data;
1018 		if (opcode == SRP_LOGIN_REJ) {
1019 			struct srp_login_rej *rej = event->private_data;
1020 			u32 reason = be32_to_cpu(rej->reason);
1021 
1022 			if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
1023 				printk(KERN_WARNING PFX
1024 				       "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
1025 			else
1026 				printk(KERN_WARNING PFX
1027 				       "SRP LOGIN REJECTED, reason 0x%08x\n", reason);
1028 		} else
1029 			printk(KERN_WARNING "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
1030 			       " opcode 0x%02x\n", opcode);
1031 		target->status = -ECONNRESET;
1032 		break;
1033 
1034 	default:
1035 		printk(KERN_WARNING "  REJ reason 0x%x\n",
1036 		       event->param.rej_rcvd.reason);
1037 		target->status = -ECONNRESET;
1038 	}
1039 }
1040 
1041 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
1042 {
1043 	struct srp_target_port *target = cm_id->context;
1044 	struct ib_qp_attr *qp_attr = NULL;
1045 	int attr_mask = 0;
1046 	int comp = 0;
1047 	int opcode = 0;
1048 
1049 	switch (event->event) {
1050 	case IB_CM_REQ_ERROR:
1051 		printk(KERN_DEBUG PFX "Sending CM REQ failed\n");
1052 		comp = 1;
1053 		target->status = -ECONNRESET;
1054 		break;
1055 
1056 	case IB_CM_REP_RECEIVED:
1057 		comp = 1;
1058 		opcode = *(u8 *) event->private_data;
1059 
1060 		if (opcode == SRP_LOGIN_RSP) {
1061 			struct srp_login_rsp *rsp = event->private_data;
1062 
1063 			target->max_ti_iu_len = be32_to_cpu(rsp->max_ti_iu_len);
1064 			target->req_lim       = be32_to_cpu(rsp->req_lim_delta);
1065 
1066 			target->scsi_host->can_queue = min(target->req_lim,
1067 							   target->scsi_host->can_queue);
1068 		} else {
1069 			printk(KERN_WARNING PFX "Unhandled RSP opcode %#x\n", opcode);
1070 			target->status = -ECONNRESET;
1071 			break;
1072 		}
1073 
1074 		target->status = srp_alloc_iu_bufs(target);
1075 		if (target->status)
1076 			break;
1077 
1078 		qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
1079 		if (!qp_attr) {
1080 			target->status = -ENOMEM;
1081 			break;
1082 		}
1083 
1084 		qp_attr->qp_state = IB_QPS_RTR;
1085 		target->status = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1086 		if (target->status)
1087 			break;
1088 
1089 		target->status = ib_modify_qp(target->qp, qp_attr, attr_mask);
1090 		if (target->status)
1091 			break;
1092 
1093 		target->status = srp_post_recv(target);
1094 		if (target->status)
1095 			break;
1096 
1097 		qp_attr->qp_state = IB_QPS_RTS;
1098 		target->status = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1099 		if (target->status)
1100 			break;
1101 
1102 		target->status = ib_modify_qp(target->qp, qp_attr, attr_mask);
1103 		if (target->status)
1104 			break;
1105 
1106 		target->status = ib_send_cm_rtu(cm_id, NULL, 0);
1107 		if (target->status)
1108 			break;
1109 
1110 		break;
1111 
1112 	case IB_CM_REJ_RECEIVED:
1113 		printk(KERN_DEBUG PFX "REJ received\n");
1114 		comp = 1;
1115 
1116 		srp_cm_rej_handler(cm_id, event, target);
1117 		break;
1118 
1119 	case IB_CM_MRA_RECEIVED:
1120 		printk(KERN_ERR PFX "MRA received\n");
1121 		break;
1122 
1123 	case IB_CM_DREP_RECEIVED:
1124 		break;
1125 
1126 	case IB_CM_TIMEWAIT_EXIT:
1127 		printk(KERN_ERR PFX "connection closed\n");
1128 
1129 		comp = 1;
1130 		target->status = 0;
1131 		break;
1132 
1133 	default:
1134 		printk(KERN_WARNING PFX "Unhandled CM event %d\n", event->event);
1135 		break;
1136 	}
1137 
1138 	if (comp)
1139 		complete(&target->done);
1140 
1141 	kfree(qp_attr);
1142 
1143 	return 0;
1144 }
1145 
1146 static int srp_send_tsk_mgmt(struct scsi_cmnd *scmnd, u8 func)
1147 {
1148 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1149 	struct srp_request *req;
1150 	struct srp_iu *iu;
1151 	struct srp_tsk_mgmt *tsk_mgmt;
1152 	int req_index;
1153 	int ret = FAILED;
1154 
1155 	spin_lock_irq(target->scsi_host->host_lock);
1156 
1157 	if (scmnd->host_scribble == (void *) -1L)
1158 		goto out;
1159 
1160 	req_index = (long) scmnd->host_scribble;
1161 	printk(KERN_ERR "Abort for req_index %d\n", req_index);
1162 
1163 	req = &target->req_ring[req_index];
1164 	init_completion(&req->done);
1165 
1166 	iu = __srp_get_tx_iu(target);
1167 	if (!iu)
1168 		goto out;
1169 
1170 	tsk_mgmt = iu->buf;
1171 	memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
1172 
1173 	tsk_mgmt->opcode 	= SRP_TSK_MGMT;
1174 	tsk_mgmt->lun 		= cpu_to_be64((u64) scmnd->device->lun << 48);
1175 	tsk_mgmt->tag 		= req_index | SRP_TAG_TSK_MGMT;
1176 	tsk_mgmt->tsk_mgmt_func = func;
1177 	tsk_mgmt->task_tag 	= req_index;
1178 
1179 	if (__srp_post_send(target, iu, sizeof *tsk_mgmt))
1180 		goto out;
1181 
1182 	req->tsk_mgmt = iu;
1183 
1184 	spin_unlock_irq(target->scsi_host->host_lock);
1185 	if (!wait_for_completion_timeout(&req->done,
1186 					 msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
1187 		return FAILED;
1188 	spin_lock_irq(target->scsi_host->host_lock);
1189 
1190 	if (req->cmd_done) {
1191 		list_del(&req->list);
1192 		req->next = target->req_head;
1193 		target->req_head = req_index;
1194 
1195 		scmnd->scsi_done(scmnd);
1196 	} else if (!req->tsk_status) {
1197 		scmnd->result = DID_ABORT << 16;
1198 		ret = SUCCESS;
1199 	}
1200 
1201 out:
1202 	spin_unlock_irq(target->scsi_host->host_lock);
1203 	return ret;
1204 }
1205 
1206 static int srp_abort(struct scsi_cmnd *scmnd)
1207 {
1208 	printk(KERN_ERR "SRP abort called\n");
1209 
1210 	return srp_send_tsk_mgmt(scmnd, SRP_TSK_ABORT_TASK);
1211 }
1212 
1213 static int srp_reset_device(struct scsi_cmnd *scmnd)
1214 {
1215 	printk(KERN_ERR "SRP reset_device called\n");
1216 
1217 	return srp_send_tsk_mgmt(scmnd, SRP_TSK_LUN_RESET);
1218 }
1219 
1220 static int srp_reset_host(struct scsi_cmnd *scmnd)
1221 {
1222 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1223 	int ret = FAILED;
1224 
1225 	printk(KERN_ERR PFX "SRP reset_host called\n");
1226 
1227 	if (!srp_reconnect_target(target))
1228 		ret = SUCCESS;
1229 
1230 	return ret;
1231 }
1232 
1233 static struct scsi_host_template srp_template = {
1234 	.module				= THIS_MODULE,
1235 	.name				= DRV_NAME,
1236 	.info				= srp_target_info,
1237 	.queuecommand			= srp_queuecommand,
1238 	.eh_abort_handler		= srp_abort,
1239 	.eh_device_reset_handler	= srp_reset_device,
1240 	.eh_host_reset_handler		= srp_reset_host,
1241 	.can_queue			= SRP_SQ_SIZE,
1242 	.this_id			= -1,
1243 	.sg_tablesize			= SRP_MAX_INDIRECT,
1244 	.cmd_per_lun			= SRP_SQ_SIZE,
1245 	.use_clustering			= ENABLE_CLUSTERING
1246 };
1247 
1248 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
1249 {
1250 	sprintf(target->target_name, "SRP.T10:%016llX",
1251 		 (unsigned long long) be64_to_cpu(target->id_ext));
1252 
1253 	if (scsi_add_host(target->scsi_host, host->dev->dma_device))
1254 		return -ENODEV;
1255 
1256 	down(&host->target_mutex);
1257 	list_add_tail(&target->list, &host->target_list);
1258 	up(&host->target_mutex);
1259 
1260 	target->state = SRP_TARGET_LIVE;
1261 
1262 	/* XXX: are we supposed to have a definition of SCAN_WILD_CARD ?? */
1263 	scsi_scan_target(&target->scsi_host->shost_gendev,
1264 			 0, target->scsi_id, ~0, 0);
1265 
1266 	return 0;
1267 }
1268 
1269 static void srp_release_class_dev(struct class_device *class_dev)
1270 {
1271 	struct srp_host *host =
1272 		container_of(class_dev, struct srp_host, class_dev);
1273 
1274 	complete(&host->released);
1275 }
1276 
1277 static struct class srp_class = {
1278 	.name    = "infiniband_srp",
1279 	.release = srp_release_class_dev
1280 };
1281 
1282 /*
1283  * Target ports are added by writing
1284  *
1285  *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
1286  *     pkey=<P_Key>,service_id=<service ID>
1287  *
1288  * to the add_target sysfs attribute.
1289  */
1290 enum {
1291 	SRP_OPT_ERR		= 0,
1292 	SRP_OPT_ID_EXT		= 1 << 0,
1293 	SRP_OPT_IOC_GUID	= 1 << 1,
1294 	SRP_OPT_DGID		= 1 << 2,
1295 	SRP_OPT_PKEY		= 1 << 3,
1296 	SRP_OPT_SERVICE_ID	= 1 << 4,
1297 	SRP_OPT_MAX_SECT	= 1 << 5,
1298 	SRP_OPT_ALL		= (SRP_OPT_ID_EXT	|
1299 				   SRP_OPT_IOC_GUID	|
1300 				   SRP_OPT_DGID		|
1301 				   SRP_OPT_PKEY		|
1302 				   SRP_OPT_SERVICE_ID),
1303 };
1304 
1305 static match_table_t srp_opt_tokens = {
1306 	{ SRP_OPT_ID_EXT,	"id_ext=%s" 	},
1307 	{ SRP_OPT_IOC_GUID,	"ioc_guid=%s" 	},
1308 	{ SRP_OPT_DGID,		"dgid=%s" 	},
1309 	{ SRP_OPT_PKEY,		"pkey=%x" 	},
1310 	{ SRP_OPT_SERVICE_ID,	"service_id=%s" },
1311 	{ SRP_OPT_MAX_SECT,     "max_sect=%d" 	},
1312 	{ SRP_OPT_ERR,		NULL 		}
1313 };
1314 
1315 static int srp_parse_options(const char *buf, struct srp_target_port *target)
1316 {
1317 	char *options, *sep_opt;
1318 	char *p;
1319 	char dgid[3];
1320 	substring_t args[MAX_OPT_ARGS];
1321 	int opt_mask = 0;
1322 	int token;
1323 	int ret = -EINVAL;
1324 	int i;
1325 
1326 	options = kstrdup(buf, GFP_KERNEL);
1327 	if (!options)
1328 		return -ENOMEM;
1329 
1330 	sep_opt = options;
1331 	while ((p = strsep(&sep_opt, ",")) != NULL) {
1332 		if (!*p)
1333 			continue;
1334 
1335 		token = match_token(p, srp_opt_tokens, args);
1336 		opt_mask |= token;
1337 
1338 		switch (token) {
1339 		case SRP_OPT_ID_EXT:
1340 			p = match_strdup(args);
1341 			target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
1342 			kfree(p);
1343 			break;
1344 
1345 		case SRP_OPT_IOC_GUID:
1346 			p = match_strdup(args);
1347 			target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
1348 			kfree(p);
1349 			break;
1350 
1351 		case SRP_OPT_DGID:
1352 			p = match_strdup(args);
1353 			if (strlen(p) != 32) {
1354 				printk(KERN_WARNING PFX "bad dest GID parameter '%s'\n", p);
1355 				goto out;
1356 			}
1357 
1358 			for (i = 0; i < 16; ++i) {
1359 				strlcpy(dgid, p + i * 2, 3);
1360 				target->path.dgid.raw[i] = simple_strtoul(dgid, NULL, 16);
1361 			}
1362 			break;
1363 
1364 		case SRP_OPT_PKEY:
1365 			if (match_hex(args, &token)) {
1366 				printk(KERN_WARNING PFX "bad P_Key parameter '%s'\n", p);
1367 				goto out;
1368 			}
1369 			target->path.pkey = cpu_to_be16(token);
1370 			break;
1371 
1372 		case SRP_OPT_SERVICE_ID:
1373 			p = match_strdup(args);
1374 			target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
1375 			kfree(p);
1376 			break;
1377 
1378 		case SRP_OPT_MAX_SECT:
1379 			if (match_int(args, &token)) {
1380 				printk(KERN_WARNING PFX "bad max sect parameter '%s'\n", p);
1381 				goto out;
1382 			}
1383 			target->scsi_host->max_sectors = token;
1384 			break;
1385 
1386 		default:
1387 			printk(KERN_WARNING PFX "unknown parameter or missing value "
1388 			       "'%s' in target creation request\n", p);
1389 			goto out;
1390 		}
1391 	}
1392 
1393 	if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
1394 		ret = 0;
1395 	else
1396 		for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
1397 			if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
1398 			    !(srp_opt_tokens[i].token & opt_mask))
1399 				printk(KERN_WARNING PFX "target creation request is "
1400 				       "missing parameter '%s'\n",
1401 				       srp_opt_tokens[i].pattern);
1402 
1403 out:
1404 	kfree(options);
1405 	return ret;
1406 }
1407 
1408 static ssize_t srp_create_target(struct class_device *class_dev,
1409 				 const char *buf, size_t count)
1410 {
1411 	struct srp_host *host =
1412 		container_of(class_dev, struct srp_host, class_dev);
1413 	struct Scsi_Host *target_host;
1414 	struct srp_target_port *target;
1415 	int ret;
1416 	int i;
1417 
1418 	target_host = scsi_host_alloc(&srp_template,
1419 				      sizeof (struct srp_target_port));
1420 	if (!target_host)
1421 		return -ENOMEM;
1422 
1423 	target_host->max_lun = SRP_MAX_LUN;
1424 
1425 	target = host_to_target(target_host);
1426 	memset(target, 0, sizeof *target);
1427 
1428 	target->scsi_host  = target_host;
1429 	target->srp_host   = host;
1430 
1431 	INIT_WORK(&target->work, srp_reconnect_work, target);
1432 
1433 	for (i = 0; i < SRP_SQ_SIZE - 1; ++i)
1434 		target->req_ring[i].next = i + 1;
1435 	target->req_ring[SRP_SQ_SIZE - 1].next = -1;
1436 	INIT_LIST_HEAD(&target->req_queue);
1437 
1438 	ret = srp_parse_options(buf, target);
1439 	if (ret)
1440 		goto err;
1441 
1442 	ib_get_cached_gid(host->dev, host->port, 0, &target->path.sgid);
1443 
1444 	printk(KERN_DEBUG PFX "new target: id_ext %016llx ioc_guid %016llx pkey %04x "
1445 	       "service_id %016llx dgid %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
1446 	       (unsigned long long) be64_to_cpu(target->id_ext),
1447 	       (unsigned long long) be64_to_cpu(target->ioc_guid),
1448 	       be16_to_cpu(target->path.pkey),
1449 	       (unsigned long long) be64_to_cpu(target->service_id),
1450 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[0]),
1451 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[2]),
1452 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[4]),
1453 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[6]),
1454 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[8]),
1455 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[10]),
1456 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[12]),
1457 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[14]));
1458 
1459 	ret = srp_create_target_ib(target);
1460 	if (ret)
1461 		goto err;
1462 
1463 	target->cm_id = ib_create_cm_id(host->dev, srp_cm_handler, target);
1464 	if (IS_ERR(target->cm_id)) {
1465 		ret = PTR_ERR(target->cm_id);
1466 		goto err_free;
1467 	}
1468 
1469 	ret = srp_connect_target(target);
1470 	if (ret) {
1471 		printk(KERN_ERR PFX "Connection failed\n");
1472 		goto err_cm_id;
1473 	}
1474 
1475 	ret = srp_add_target(host, target);
1476 	if (ret)
1477 		goto err_disconnect;
1478 
1479 	return count;
1480 
1481 err_disconnect:
1482 	srp_disconnect_target(target);
1483 
1484 err_cm_id:
1485 	ib_destroy_cm_id(target->cm_id);
1486 
1487 err_free:
1488 	srp_free_target_ib(target);
1489 
1490 err:
1491 	scsi_host_put(target_host);
1492 
1493 	return ret;
1494 }
1495 
1496 static CLASS_DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
1497 
1498 static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
1499 {
1500 	struct srp_host *host =
1501 		container_of(class_dev, struct srp_host, class_dev);
1502 
1503 	return sprintf(buf, "%s\n", host->dev->name);
1504 }
1505 
1506 static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
1507 
1508 static ssize_t show_port(struct class_device *class_dev, char *buf)
1509 {
1510 	struct srp_host *host =
1511 		container_of(class_dev, struct srp_host, class_dev);
1512 
1513 	return sprintf(buf, "%d\n", host->port);
1514 }
1515 
1516 static CLASS_DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
1517 
1518 static struct srp_host *srp_add_port(struct ib_device *device,
1519 				     __be64 node_guid, u8 port)
1520 {
1521 	struct srp_host *host;
1522 
1523 	host = kzalloc(sizeof *host, GFP_KERNEL);
1524 	if (!host)
1525 		return NULL;
1526 
1527 	INIT_LIST_HEAD(&host->target_list);
1528 	init_MUTEX(&host->target_mutex);
1529 	init_completion(&host->released);
1530 	host->dev  = device;
1531 	host->port = port;
1532 
1533 	host->initiator_port_id[7] = port;
1534 	memcpy(host->initiator_port_id + 8, &node_guid, 8);
1535 
1536 	host->pd   = ib_alloc_pd(device);
1537 	if (IS_ERR(host->pd))
1538 		goto err_free;
1539 
1540 	host->mr   = ib_get_dma_mr(host->pd,
1541 				   IB_ACCESS_LOCAL_WRITE |
1542 				   IB_ACCESS_REMOTE_READ |
1543 				   IB_ACCESS_REMOTE_WRITE);
1544 	if (IS_ERR(host->mr))
1545 		goto err_pd;
1546 
1547 	host->class_dev.class = &srp_class;
1548 	host->class_dev.dev   = device->dma_device;
1549 	snprintf(host->class_dev.class_id, BUS_ID_SIZE, "srp-%s-%d",
1550 		 device->name, port);
1551 
1552 	if (class_device_register(&host->class_dev))
1553 		goto err_mr;
1554 	if (class_device_create_file(&host->class_dev, &class_device_attr_add_target))
1555 		goto err_class;
1556 	if (class_device_create_file(&host->class_dev, &class_device_attr_ibdev))
1557 		goto err_class;
1558 	if (class_device_create_file(&host->class_dev, &class_device_attr_port))
1559 		goto err_class;
1560 
1561 	return host;
1562 
1563 err_class:
1564 	class_device_unregister(&host->class_dev);
1565 
1566 err_mr:
1567 	ib_dereg_mr(host->mr);
1568 
1569 err_pd:
1570 	ib_dealloc_pd(host->pd);
1571 
1572 err_free:
1573 	kfree(host);
1574 
1575 	return NULL;
1576 }
1577 
1578 static void srp_add_one(struct ib_device *device)
1579 {
1580 	struct list_head *dev_list;
1581 	struct srp_host *host;
1582 	struct ib_device_attr *dev_attr;
1583 	int s, e, p;
1584 
1585 	dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
1586 	if (!dev_attr)
1587 		return;
1588 
1589 	if (ib_query_device(device, dev_attr)) {
1590 		printk(KERN_WARNING PFX "Couldn't query node GUID for %s.\n",
1591 		       device->name);
1592 		goto out;
1593 	}
1594 
1595 	dev_list = kmalloc(sizeof *dev_list, GFP_KERNEL);
1596 	if (!dev_list)
1597 		goto out;
1598 
1599 	INIT_LIST_HEAD(dev_list);
1600 
1601 	if (device->node_type == IB_NODE_SWITCH) {
1602 		s = 0;
1603 		e = 0;
1604 	} else {
1605 		s = 1;
1606 		e = device->phys_port_cnt;
1607 	}
1608 
1609 	for (p = s; p <= e; ++p) {
1610 		host = srp_add_port(device, dev_attr->node_guid, p);
1611 		if (host)
1612 			list_add_tail(&host->list, dev_list);
1613 	}
1614 
1615 	ib_set_client_data(device, &srp_client, dev_list);
1616 
1617 out:
1618 	kfree(dev_attr);
1619 }
1620 
1621 static void srp_remove_one(struct ib_device *device)
1622 {
1623 	struct list_head *dev_list;
1624 	struct srp_host *host, *tmp_host;
1625 	LIST_HEAD(target_list);
1626 	struct srp_target_port *target, *tmp_target;
1627 	unsigned long flags;
1628 
1629 	dev_list = ib_get_client_data(device, &srp_client);
1630 
1631 	list_for_each_entry_safe(host, tmp_host, dev_list, list) {
1632 		class_device_unregister(&host->class_dev);
1633 		/*
1634 		 * Wait for the sysfs entry to go away, so that no new
1635 		 * target ports can be created.
1636 		 */
1637 		wait_for_completion(&host->released);
1638 
1639 		/*
1640 		 * Mark all target ports as removed, so we stop queueing
1641 		 * commands and don't try to reconnect.
1642 		 */
1643 		down(&host->target_mutex);
1644 		list_for_each_entry_safe(target, tmp_target,
1645 					 &host->target_list, list) {
1646 			spin_lock_irqsave(target->scsi_host->host_lock, flags);
1647 			if (target->state != SRP_TARGET_REMOVED)
1648 				target->state = SRP_TARGET_REMOVED;
1649 			spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
1650 		}
1651 		up(&host->target_mutex);
1652 
1653 		/*
1654 		 * Wait for any reconnection tasks that may have
1655 		 * started before we marked our target ports as
1656 		 * removed, and any target port removal tasks.
1657 		 */
1658 		flush_scheduled_work();
1659 
1660 		list_for_each_entry_safe(target, tmp_target,
1661 					 &host->target_list, list) {
1662 			scsi_remove_host(target->scsi_host);
1663 			srp_disconnect_target(target);
1664 			ib_destroy_cm_id(target->cm_id);
1665 			srp_free_target_ib(target);
1666 			scsi_host_put(target->scsi_host);
1667 		}
1668 
1669 		ib_dereg_mr(host->mr);
1670 		ib_dealloc_pd(host->pd);
1671 		kfree(host);
1672 	}
1673 
1674 	kfree(dev_list);
1675 }
1676 
1677 static int __init srp_init_module(void)
1678 {
1679 	int ret;
1680 
1681 	ret = class_register(&srp_class);
1682 	if (ret) {
1683 		printk(KERN_ERR PFX "couldn't register class infiniband_srp\n");
1684 		return ret;
1685 	}
1686 
1687 	ret = ib_register_client(&srp_client);
1688 	if (ret) {
1689 		printk(KERN_ERR PFX "couldn't register IB client\n");
1690 		class_unregister(&srp_class);
1691 		return ret;
1692 	}
1693 
1694 	return 0;
1695 }
1696 
1697 static void __exit srp_cleanup_module(void)
1698 {
1699 	ib_unregister_client(&srp_client);
1700 	class_unregister(&srp_class);
1701 }
1702 
1703 module_init(srp_init_module);
1704 module_exit(srp_cleanup_module);
1705