xref: /linux/drivers/infiniband/ulp/srp/ib_srp.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
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 #include <linux/jiffies.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 	mutex_lock(&target->srp_host->target_mutex);
361 	list_del(&target->list);
362 	mutex_unlock(&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 scatterlist *scat;
507 	struct srp_cmd *cmd = req->cmd->buf;
508 	int len, nents, count;
509 	int i;
510 	u8 fmt;
511 
512 	if (!scmnd->request_buffer || scmnd->sc_data_direction == DMA_NONE)
513 		return sizeof (struct srp_cmd);
514 
515 	if (scmnd->sc_data_direction != DMA_FROM_DEVICE &&
516 	    scmnd->sc_data_direction != DMA_TO_DEVICE) {
517 		printk(KERN_WARNING PFX "Unhandled data direction %d\n",
518 		       scmnd->sc_data_direction);
519 		return -EINVAL;
520 	}
521 
522 	/*
523 	 * This handling of non-SG commands can be killed when the
524 	 * SCSI midlayer no longer generates non-SG commands.
525 	 */
526 	if (likely(scmnd->use_sg)) {
527 		nents = scmnd->use_sg;
528 		scat  = scmnd->request_buffer;
529 	} else {
530 		nents = 1;
531 		scat  = &req->fake_sg;
532 		sg_init_one(scat, scmnd->request_buffer, scmnd->request_bufflen);
533 	}
534 
535 	count = dma_map_sg(target->srp_host->dev->dma_device, scat, nents,
536 			   scmnd->sc_data_direction);
537 
538 	if (count == 1) {
539 		struct srp_direct_buf *buf = (void *) cmd->add_data;
540 
541 		fmt = SRP_DATA_DESC_DIRECT;
542 
543 		buf->va  = cpu_to_be64(sg_dma_address(scat));
544 		buf->key = cpu_to_be32(target->srp_host->mr->rkey);
545 		buf->len = cpu_to_be32(sg_dma_len(scat));
546 
547 		len = sizeof (struct srp_cmd) +
548 			sizeof (struct srp_direct_buf);
549 	} else {
550 		struct srp_indirect_buf *buf = (void *) cmd->add_data;
551 		u32 datalen = 0;
552 
553 		fmt = SRP_DATA_DESC_INDIRECT;
554 
555 		if (scmnd->sc_data_direction == DMA_TO_DEVICE)
556 			cmd->data_out_desc_cnt = count;
557 		else
558 			cmd->data_in_desc_cnt = count;
559 
560 		buf->table_desc.va  = cpu_to_be64(req->cmd->dma +
561 						  sizeof *cmd +
562 						  sizeof *buf);
563 		buf->table_desc.key =
564 			cpu_to_be32(target->srp_host->mr->rkey);
565 		buf->table_desc.len =
566 			cpu_to_be32(count * sizeof (struct srp_direct_buf));
567 
568 		for (i = 0; i < count; ++i) {
569 			buf->desc_list[i].va  = cpu_to_be64(sg_dma_address(&scat[i]));
570 			buf->desc_list[i].key =
571 				cpu_to_be32(target->srp_host->mr->rkey);
572 			buf->desc_list[i].len = cpu_to_be32(sg_dma_len(&scat[i]));
573 
574 			datalen += sg_dma_len(&scat[i]);
575 		}
576 
577 		buf->len = cpu_to_be32(datalen);
578 
579 		len = sizeof (struct srp_cmd) +
580 			sizeof (struct srp_indirect_buf) +
581 			count * sizeof (struct srp_direct_buf);
582 	}
583 
584 	if (scmnd->sc_data_direction == DMA_TO_DEVICE)
585 		cmd->buf_fmt = fmt << 4;
586 	else
587 		cmd->buf_fmt = fmt;
588 
589 	return len;
590 }
591 
592 static void srp_unmap_data(struct scsi_cmnd *scmnd,
593 			   struct srp_target_port *target,
594 			   struct srp_request *req)
595 {
596 	struct scatterlist *scat;
597 	int nents;
598 
599 	if (!scmnd->request_buffer ||
600 	    (scmnd->sc_data_direction != DMA_TO_DEVICE &&
601 	     scmnd->sc_data_direction != DMA_FROM_DEVICE))
602 		return;
603 
604 	/*
605 	 * This handling of non-SG commands can be killed when the
606 	 * SCSI midlayer no longer generates non-SG commands.
607 	 */
608 	if (likely(scmnd->use_sg)) {
609 		nents = scmnd->use_sg;
610 		scat  = scmnd->request_buffer;
611 	} else {
612 		nents = 1;
613 		scat  = &req->fake_sg;
614 	}
615 
616 	dma_unmap_sg(target->srp_host->dev->dma_device, scat, nents,
617 		     scmnd->sc_data_direction);
618 }
619 
620 static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
621 {
622 	struct srp_request *req;
623 	struct scsi_cmnd *scmnd;
624 	unsigned long flags;
625 	s32 delta;
626 
627 	delta = (s32) be32_to_cpu(rsp->req_lim_delta);
628 
629 	spin_lock_irqsave(target->scsi_host->host_lock, flags);
630 
631 	target->req_lim += delta;
632 
633 	req = &target->req_ring[rsp->tag & ~SRP_TAG_TSK_MGMT];
634 
635 	if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
636 		if (be32_to_cpu(rsp->resp_data_len) < 4)
637 			req->tsk_status = -1;
638 		else
639 			req->tsk_status = rsp->data[3];
640 		complete(&req->done);
641 	} else {
642 		scmnd 	      = req->scmnd;
643 		if (!scmnd)
644 			printk(KERN_ERR "Null scmnd for RSP w/tag %016llx\n",
645 			       (unsigned long long) rsp->tag);
646 		scmnd->result = rsp->status;
647 
648 		if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
649 			memcpy(scmnd->sense_buffer, rsp->data +
650 			       be32_to_cpu(rsp->resp_data_len),
651 			       min_t(int, be32_to_cpu(rsp->sense_data_len),
652 				     SCSI_SENSE_BUFFERSIZE));
653 		}
654 
655 		if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
656 			scmnd->resid = be32_to_cpu(rsp->data_out_res_cnt);
657 		else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
658 			scmnd->resid = be32_to_cpu(rsp->data_in_res_cnt);
659 
660 		srp_unmap_data(scmnd, target, req);
661 
662 		if (!req->tsk_mgmt) {
663 			req->scmnd = NULL;
664 			scmnd->host_scribble = (void *) -1L;
665 			scmnd->scsi_done(scmnd);
666 
667 			list_del(&req->list);
668 			req->next = target->req_head;
669 			target->req_head = rsp->tag & ~SRP_TAG_TSK_MGMT;
670 		} else
671 			req->cmd_done = 1;
672 	}
673 
674 	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
675 }
676 
677 static void srp_reconnect_work(void *target_ptr)
678 {
679 	struct srp_target_port *target = target_ptr;
680 
681 	srp_reconnect_target(target);
682 }
683 
684 static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
685 {
686 	struct srp_iu *iu;
687 	u8 opcode;
688 
689 	iu = target->rx_ring[wc->wr_id & ~SRP_OP_RECV];
690 
691 	dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
692 				target->max_ti_iu_len, DMA_FROM_DEVICE);
693 
694 	opcode = *(u8 *) iu->buf;
695 
696 	if (0) {
697 		int i;
698 
699 		printk(KERN_ERR PFX "recv completion, opcode 0x%02x\n", opcode);
700 
701 		for (i = 0; i < wc->byte_len; ++i) {
702 			if (i % 8 == 0)
703 				printk(KERN_ERR "  [%02x] ", i);
704 			printk(" %02x", ((u8 *) iu->buf)[i]);
705 			if ((i + 1) % 8 == 0)
706 				printk("\n");
707 		}
708 
709 		if (wc->byte_len % 8)
710 			printk("\n");
711 	}
712 
713 	switch (opcode) {
714 	case SRP_RSP:
715 		srp_process_rsp(target, iu->buf);
716 		break;
717 
718 	case SRP_T_LOGOUT:
719 		/* XXX Handle target logout */
720 		printk(KERN_WARNING PFX "Got target logout request\n");
721 		break;
722 
723 	default:
724 		printk(KERN_WARNING PFX "Unhandled SRP opcode 0x%02x\n", opcode);
725 		break;
726 	}
727 
728 	dma_sync_single_for_device(target->srp_host->dev->dma_device, iu->dma,
729 				   target->max_ti_iu_len, DMA_FROM_DEVICE);
730 }
731 
732 static void srp_completion(struct ib_cq *cq, void *target_ptr)
733 {
734 	struct srp_target_port *target = target_ptr;
735 	struct ib_wc wc;
736 	unsigned long flags;
737 
738 	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
739 	while (ib_poll_cq(cq, 1, &wc) > 0) {
740 		if (wc.status) {
741 			printk(KERN_ERR PFX "failed %s status %d\n",
742 			       wc.wr_id & SRP_OP_RECV ? "receive" : "send",
743 			       wc.status);
744 			spin_lock_irqsave(target->scsi_host->host_lock, flags);
745 			if (target->state == SRP_TARGET_LIVE)
746 				schedule_work(&target->work);
747 			spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
748 			break;
749 		}
750 
751 		if (wc.wr_id & SRP_OP_RECV)
752 			srp_handle_recv(target, &wc);
753 		else
754 			++target->tx_tail;
755 	}
756 }
757 
758 static int __srp_post_recv(struct srp_target_port *target)
759 {
760 	struct srp_iu *iu;
761 	struct ib_sge list;
762 	struct ib_recv_wr wr, *bad_wr;
763 	unsigned int next;
764 	int ret;
765 
766 	next 	 = target->rx_head & (SRP_RQ_SIZE - 1);
767 	wr.wr_id = next | SRP_OP_RECV;
768 	iu 	 = target->rx_ring[next];
769 
770 	list.addr   = iu->dma;
771 	list.length = iu->size;
772 	list.lkey   = target->srp_host->mr->lkey;
773 
774 	wr.next     = NULL;
775 	wr.sg_list  = &list;
776 	wr.num_sge  = 1;
777 
778 	ret = ib_post_recv(target->qp, &wr, &bad_wr);
779 	if (!ret)
780 		++target->rx_head;
781 
782 	return ret;
783 }
784 
785 static int srp_post_recv(struct srp_target_port *target)
786 {
787 	unsigned long flags;
788 	int ret;
789 
790 	spin_lock_irqsave(target->scsi_host->host_lock, flags);
791 	ret = __srp_post_recv(target);
792 	spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
793 
794 	return ret;
795 }
796 
797 /*
798  * Must be called with target->scsi_host->host_lock held to protect
799  * req_lim and tx_head.  Lock cannot be dropped between call here and
800  * call to __srp_post_send().
801  */
802 static struct srp_iu *__srp_get_tx_iu(struct srp_target_port *target)
803 {
804 	if (target->tx_head - target->tx_tail >= SRP_SQ_SIZE)
805 		return NULL;
806 
807 	if (unlikely(target->req_lim < 1)) {
808 		if (printk_ratelimit())
809 			printk(KERN_DEBUG PFX "Target has req_lim %d\n",
810 			       target->req_lim);
811 		return NULL;
812 	}
813 
814 	return target->tx_ring[target->tx_head & SRP_SQ_SIZE];
815 }
816 
817 /*
818  * Must be called with target->scsi_host->host_lock held to protect
819  * req_lim and tx_head.
820  */
821 static int __srp_post_send(struct srp_target_port *target,
822 			   struct srp_iu *iu, int len)
823 {
824 	struct ib_sge list;
825 	struct ib_send_wr wr, *bad_wr;
826 	int ret = 0;
827 
828 	list.addr   = iu->dma;
829 	list.length = len;
830 	list.lkey   = target->srp_host->mr->lkey;
831 
832 	wr.next       = NULL;
833 	wr.wr_id      = target->tx_head & SRP_SQ_SIZE;
834 	wr.sg_list    = &list;
835 	wr.num_sge    = 1;
836 	wr.opcode     = IB_WR_SEND;
837 	wr.send_flags = IB_SEND_SIGNALED;
838 
839 	ret = ib_post_send(target->qp, &wr, &bad_wr);
840 
841 	if (!ret) {
842 		++target->tx_head;
843 		--target->req_lim;
844 	}
845 
846 	return ret;
847 }
848 
849 static int srp_queuecommand(struct scsi_cmnd *scmnd,
850 			    void (*done)(struct scsi_cmnd *))
851 {
852 	struct srp_target_port *target = host_to_target(scmnd->device->host);
853 	struct srp_request *req;
854 	struct srp_iu *iu;
855 	struct srp_cmd *cmd;
856 	long req_index;
857 	int len;
858 
859 	if (target->state == SRP_TARGET_CONNECTING)
860 		goto err;
861 
862 	if (target->state == SRP_TARGET_DEAD ||
863 	    target->state == SRP_TARGET_REMOVED) {
864 		scmnd->result = DID_BAD_TARGET << 16;
865 		done(scmnd);
866 		return 0;
867 	}
868 
869 	iu = __srp_get_tx_iu(target);
870 	if (!iu)
871 		goto err;
872 
873 	dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
874 				SRP_MAX_IU_LEN, DMA_TO_DEVICE);
875 
876 	req_index = target->req_head;
877 
878 	scmnd->scsi_done     = done;
879 	scmnd->result        = 0;
880 	scmnd->host_scribble = (void *) req_index;
881 
882 	cmd = iu->buf;
883 	memset(cmd, 0, sizeof *cmd);
884 
885 	cmd->opcode = SRP_CMD;
886 	cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
887 	cmd->tag    = req_index;
888 	memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
889 
890 	req = &target->req_ring[req_index];
891 
892 	req->scmnd    = scmnd;
893 	req->cmd      = iu;
894 	req->cmd_done = 0;
895 	req->tsk_mgmt = NULL;
896 
897 	len = srp_map_data(scmnd, target, req);
898 	if (len < 0) {
899 		printk(KERN_ERR PFX "Failed to map data\n");
900 		goto err;
901 	}
902 
903 	if (__srp_post_recv(target)) {
904 		printk(KERN_ERR PFX "Recv failed\n");
905 		goto err_unmap;
906 	}
907 
908 	dma_sync_single_for_device(target->srp_host->dev->dma_device, iu->dma,
909 				   SRP_MAX_IU_LEN, DMA_TO_DEVICE);
910 
911 	if (__srp_post_send(target, iu, len)) {
912 		printk(KERN_ERR PFX "Send failed\n");
913 		goto err_unmap;
914 	}
915 
916 	target->req_head = req->next;
917 	list_add_tail(&req->list, &target->req_queue);
918 
919 	return 0;
920 
921 err_unmap:
922 	srp_unmap_data(scmnd, target, req);
923 
924 err:
925 	return SCSI_MLQUEUE_HOST_BUSY;
926 }
927 
928 static int srp_alloc_iu_bufs(struct srp_target_port *target)
929 {
930 	int i;
931 
932 	for (i = 0; i < SRP_RQ_SIZE; ++i) {
933 		target->rx_ring[i] = srp_alloc_iu(target->srp_host,
934 						  target->max_ti_iu_len,
935 						  GFP_KERNEL, DMA_FROM_DEVICE);
936 		if (!target->rx_ring[i])
937 			goto err;
938 	}
939 
940 	for (i = 0; i < SRP_SQ_SIZE + 1; ++i) {
941 		target->tx_ring[i] = srp_alloc_iu(target->srp_host,
942 						  SRP_MAX_IU_LEN,
943 						  GFP_KERNEL, DMA_TO_DEVICE);
944 		if (!target->tx_ring[i])
945 			goto err;
946 	}
947 
948 	return 0;
949 
950 err:
951 	for (i = 0; i < SRP_RQ_SIZE; ++i) {
952 		srp_free_iu(target->srp_host, target->rx_ring[i]);
953 		target->rx_ring[i] = NULL;
954 	}
955 
956 	for (i = 0; i < SRP_SQ_SIZE + 1; ++i) {
957 		srp_free_iu(target->srp_host, target->tx_ring[i]);
958 		target->tx_ring[i] = NULL;
959 	}
960 
961 	return -ENOMEM;
962 }
963 
964 static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
965 			       struct ib_cm_event *event,
966 			       struct srp_target_port *target)
967 {
968 	struct ib_class_port_info *cpi;
969 	int opcode;
970 
971 	switch (event->param.rej_rcvd.reason) {
972 	case IB_CM_REJ_PORT_CM_REDIRECT:
973 		cpi = event->param.rej_rcvd.ari;
974 		target->path.dlid = cpi->redirect_lid;
975 		target->path.pkey = cpi->redirect_pkey;
976 		cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
977 		memcpy(target->path.dgid.raw, cpi->redirect_gid, 16);
978 
979 		target->status = target->path.dlid ?
980 			SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
981 		break;
982 
983 	case IB_CM_REJ_PORT_REDIRECT:
984 		if (topspin_workarounds &&
985 		    !memcmp(&target->ioc_guid, topspin_oui, 3)) {
986 			/*
987 			 * Topspin/Cisco SRP gateways incorrectly send
988 			 * reject reason code 25 when they mean 24
989 			 * (port redirect).
990 			 */
991 			memcpy(target->path.dgid.raw,
992 			       event->param.rej_rcvd.ari, 16);
993 
994 			printk(KERN_DEBUG PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
995 			       (unsigned long long) be64_to_cpu(target->path.dgid.global.subnet_prefix),
996 			       (unsigned long long) be64_to_cpu(target->path.dgid.global.interface_id));
997 
998 			target->status = SRP_PORT_REDIRECT;
999 		} else {
1000 			printk(KERN_WARNING "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
1001 			target->status = -ECONNRESET;
1002 		}
1003 		break;
1004 
1005 	case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
1006 		printk(KERN_WARNING "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
1007 		target->status = -ECONNRESET;
1008 		break;
1009 
1010 	case IB_CM_REJ_CONSUMER_DEFINED:
1011 		opcode = *(u8 *) event->private_data;
1012 		if (opcode == SRP_LOGIN_REJ) {
1013 			struct srp_login_rej *rej = event->private_data;
1014 			u32 reason = be32_to_cpu(rej->reason);
1015 
1016 			if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
1017 				printk(KERN_WARNING PFX
1018 				       "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
1019 			else
1020 				printk(KERN_WARNING PFX
1021 				       "SRP LOGIN REJECTED, reason 0x%08x\n", reason);
1022 		} else
1023 			printk(KERN_WARNING "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
1024 			       " opcode 0x%02x\n", opcode);
1025 		target->status = -ECONNRESET;
1026 		break;
1027 
1028 	default:
1029 		printk(KERN_WARNING "  REJ reason 0x%x\n",
1030 		       event->param.rej_rcvd.reason);
1031 		target->status = -ECONNRESET;
1032 	}
1033 }
1034 
1035 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
1036 {
1037 	struct srp_target_port *target = cm_id->context;
1038 	struct ib_qp_attr *qp_attr = NULL;
1039 	int attr_mask = 0;
1040 	int comp = 0;
1041 	int opcode = 0;
1042 
1043 	switch (event->event) {
1044 	case IB_CM_REQ_ERROR:
1045 		printk(KERN_DEBUG PFX "Sending CM REQ failed\n");
1046 		comp = 1;
1047 		target->status = -ECONNRESET;
1048 		break;
1049 
1050 	case IB_CM_REP_RECEIVED:
1051 		comp = 1;
1052 		opcode = *(u8 *) event->private_data;
1053 
1054 		if (opcode == SRP_LOGIN_RSP) {
1055 			struct srp_login_rsp *rsp = event->private_data;
1056 
1057 			target->max_ti_iu_len = be32_to_cpu(rsp->max_ti_iu_len);
1058 			target->req_lim       = be32_to_cpu(rsp->req_lim_delta);
1059 
1060 			target->scsi_host->can_queue = min(target->req_lim,
1061 							   target->scsi_host->can_queue);
1062 		} else {
1063 			printk(KERN_WARNING PFX "Unhandled RSP opcode %#x\n", opcode);
1064 			target->status = -ECONNRESET;
1065 			break;
1066 		}
1067 
1068 		target->status = srp_alloc_iu_bufs(target);
1069 		if (target->status)
1070 			break;
1071 
1072 		qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
1073 		if (!qp_attr) {
1074 			target->status = -ENOMEM;
1075 			break;
1076 		}
1077 
1078 		qp_attr->qp_state = IB_QPS_RTR;
1079 		target->status = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1080 		if (target->status)
1081 			break;
1082 
1083 		target->status = ib_modify_qp(target->qp, qp_attr, attr_mask);
1084 		if (target->status)
1085 			break;
1086 
1087 		target->status = srp_post_recv(target);
1088 		if (target->status)
1089 			break;
1090 
1091 		qp_attr->qp_state = IB_QPS_RTS;
1092 		target->status = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1093 		if (target->status)
1094 			break;
1095 
1096 		target->status = ib_modify_qp(target->qp, qp_attr, attr_mask);
1097 		if (target->status)
1098 			break;
1099 
1100 		target->status = ib_send_cm_rtu(cm_id, NULL, 0);
1101 		if (target->status)
1102 			break;
1103 
1104 		break;
1105 
1106 	case IB_CM_REJ_RECEIVED:
1107 		printk(KERN_DEBUG PFX "REJ received\n");
1108 		comp = 1;
1109 
1110 		srp_cm_rej_handler(cm_id, event, target);
1111 		break;
1112 
1113 	case IB_CM_MRA_RECEIVED:
1114 		printk(KERN_ERR PFX "MRA received\n");
1115 		break;
1116 
1117 	case IB_CM_DREP_RECEIVED:
1118 		break;
1119 
1120 	case IB_CM_TIMEWAIT_EXIT:
1121 		printk(KERN_ERR PFX "connection closed\n");
1122 
1123 		comp = 1;
1124 		target->status = 0;
1125 		break;
1126 
1127 	default:
1128 		printk(KERN_WARNING PFX "Unhandled CM event %d\n", event->event);
1129 		break;
1130 	}
1131 
1132 	if (comp)
1133 		complete(&target->done);
1134 
1135 	kfree(qp_attr);
1136 
1137 	return 0;
1138 }
1139 
1140 static int srp_send_tsk_mgmt(struct scsi_cmnd *scmnd, u8 func)
1141 {
1142 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1143 	struct srp_request *req;
1144 	struct srp_iu *iu;
1145 	struct srp_tsk_mgmt *tsk_mgmt;
1146 	int req_index;
1147 	int ret = FAILED;
1148 
1149 	spin_lock_irq(target->scsi_host->host_lock);
1150 
1151 	if (target->state == SRP_TARGET_DEAD ||
1152 	    target->state == SRP_TARGET_REMOVED) {
1153 		scmnd->result = DID_BAD_TARGET << 16;
1154 		goto out;
1155 	}
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 ssize_t show_id_ext(struct class_device *cdev, char *buf)
1234 {
1235 	struct srp_target_port *target = host_to_target(class_to_shost(cdev));
1236 
1237 	if (target->state == SRP_TARGET_DEAD ||
1238 	    target->state == SRP_TARGET_REMOVED)
1239 		return -ENODEV;
1240 
1241 	return sprintf(buf, "0x%016llx\n",
1242 		       (unsigned long long) be64_to_cpu(target->id_ext));
1243 }
1244 
1245 static ssize_t show_ioc_guid(struct class_device *cdev, char *buf)
1246 {
1247 	struct srp_target_port *target = host_to_target(class_to_shost(cdev));
1248 
1249 	if (target->state == SRP_TARGET_DEAD ||
1250 	    target->state == SRP_TARGET_REMOVED)
1251 		return -ENODEV;
1252 
1253 	return sprintf(buf, "0x%016llx\n",
1254 		       (unsigned long long) be64_to_cpu(target->ioc_guid));
1255 }
1256 
1257 static ssize_t show_service_id(struct class_device *cdev, char *buf)
1258 {
1259 	struct srp_target_port *target = host_to_target(class_to_shost(cdev));
1260 
1261 	if (target->state == SRP_TARGET_DEAD ||
1262 	    target->state == SRP_TARGET_REMOVED)
1263 		return -ENODEV;
1264 
1265 	return sprintf(buf, "0x%016llx\n",
1266 		       (unsigned long long) be64_to_cpu(target->service_id));
1267 }
1268 
1269 static ssize_t show_pkey(struct class_device *cdev, char *buf)
1270 {
1271 	struct srp_target_port *target = host_to_target(class_to_shost(cdev));
1272 
1273 	if (target->state == SRP_TARGET_DEAD ||
1274 	    target->state == SRP_TARGET_REMOVED)
1275 		return -ENODEV;
1276 
1277 	return sprintf(buf, "0x%04x\n", be16_to_cpu(target->path.pkey));
1278 }
1279 
1280 static ssize_t show_dgid(struct class_device *cdev, char *buf)
1281 {
1282 	struct srp_target_port *target = host_to_target(class_to_shost(cdev));
1283 
1284 	if (target->state == SRP_TARGET_DEAD ||
1285 	    target->state == SRP_TARGET_REMOVED)
1286 		return -ENODEV;
1287 
1288 	return sprintf(buf, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
1289 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[0]),
1290 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[1]),
1291 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[2]),
1292 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[3]),
1293 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[4]),
1294 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[5]),
1295 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[6]),
1296 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[7]));
1297 }
1298 
1299 static CLASS_DEVICE_ATTR(id_ext,	S_IRUGO, show_id_ext,		NULL);
1300 static CLASS_DEVICE_ATTR(ioc_guid,	S_IRUGO, show_ioc_guid,		NULL);
1301 static CLASS_DEVICE_ATTR(service_id,	S_IRUGO, show_service_id,	NULL);
1302 static CLASS_DEVICE_ATTR(pkey,		S_IRUGO, show_pkey,		NULL);
1303 static CLASS_DEVICE_ATTR(dgid,		S_IRUGO, show_dgid,		NULL);
1304 
1305 static struct class_device_attribute *srp_host_attrs[] = {
1306 	&class_device_attr_id_ext,
1307 	&class_device_attr_ioc_guid,
1308 	&class_device_attr_service_id,
1309 	&class_device_attr_pkey,
1310 	&class_device_attr_dgid,
1311 	NULL
1312 };
1313 
1314 static struct scsi_host_template srp_template = {
1315 	.module				= THIS_MODULE,
1316 	.name				= DRV_NAME,
1317 	.info				= srp_target_info,
1318 	.queuecommand			= srp_queuecommand,
1319 	.eh_abort_handler		= srp_abort,
1320 	.eh_device_reset_handler	= srp_reset_device,
1321 	.eh_host_reset_handler		= srp_reset_host,
1322 	.can_queue			= SRP_SQ_SIZE,
1323 	.this_id			= -1,
1324 	.sg_tablesize			= SRP_MAX_INDIRECT,
1325 	.cmd_per_lun			= SRP_SQ_SIZE,
1326 	.use_clustering			= ENABLE_CLUSTERING,
1327 	.shost_attrs			= srp_host_attrs
1328 };
1329 
1330 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
1331 {
1332 	sprintf(target->target_name, "SRP.T10:%016llX",
1333 		 (unsigned long long) be64_to_cpu(target->id_ext));
1334 
1335 	if (scsi_add_host(target->scsi_host, host->dev->dma_device))
1336 		return -ENODEV;
1337 
1338 	mutex_lock(&host->target_mutex);
1339 	list_add_tail(&target->list, &host->target_list);
1340 	mutex_unlock(&host->target_mutex);
1341 
1342 	target->state = SRP_TARGET_LIVE;
1343 
1344 	/* XXX: are we supposed to have a definition of SCAN_WILD_CARD ?? */
1345 	scsi_scan_target(&target->scsi_host->shost_gendev,
1346 			 0, target->scsi_id, ~0, 0);
1347 
1348 	return 0;
1349 }
1350 
1351 static void srp_release_class_dev(struct class_device *class_dev)
1352 {
1353 	struct srp_host *host =
1354 		container_of(class_dev, struct srp_host, class_dev);
1355 
1356 	complete(&host->released);
1357 }
1358 
1359 static struct class srp_class = {
1360 	.name    = "infiniband_srp",
1361 	.release = srp_release_class_dev
1362 };
1363 
1364 /*
1365  * Target ports are added by writing
1366  *
1367  *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
1368  *     pkey=<P_Key>,service_id=<service ID>
1369  *
1370  * to the add_target sysfs attribute.
1371  */
1372 enum {
1373 	SRP_OPT_ERR		= 0,
1374 	SRP_OPT_ID_EXT		= 1 << 0,
1375 	SRP_OPT_IOC_GUID	= 1 << 1,
1376 	SRP_OPT_DGID		= 1 << 2,
1377 	SRP_OPT_PKEY		= 1 << 3,
1378 	SRP_OPT_SERVICE_ID	= 1 << 4,
1379 	SRP_OPT_MAX_SECT	= 1 << 5,
1380 	SRP_OPT_ALL		= (SRP_OPT_ID_EXT	|
1381 				   SRP_OPT_IOC_GUID	|
1382 				   SRP_OPT_DGID		|
1383 				   SRP_OPT_PKEY		|
1384 				   SRP_OPT_SERVICE_ID),
1385 };
1386 
1387 static match_table_t srp_opt_tokens = {
1388 	{ SRP_OPT_ID_EXT,	"id_ext=%s" 	},
1389 	{ SRP_OPT_IOC_GUID,	"ioc_guid=%s" 	},
1390 	{ SRP_OPT_DGID,		"dgid=%s" 	},
1391 	{ SRP_OPT_PKEY,		"pkey=%x" 	},
1392 	{ SRP_OPT_SERVICE_ID,	"service_id=%s" },
1393 	{ SRP_OPT_MAX_SECT,     "max_sect=%d" 	},
1394 	{ SRP_OPT_ERR,		NULL 		}
1395 };
1396 
1397 static int srp_parse_options(const char *buf, struct srp_target_port *target)
1398 {
1399 	char *options, *sep_opt;
1400 	char *p;
1401 	char dgid[3];
1402 	substring_t args[MAX_OPT_ARGS];
1403 	int opt_mask = 0;
1404 	int token;
1405 	int ret = -EINVAL;
1406 	int i;
1407 
1408 	options = kstrdup(buf, GFP_KERNEL);
1409 	if (!options)
1410 		return -ENOMEM;
1411 
1412 	sep_opt = options;
1413 	while ((p = strsep(&sep_opt, ",")) != NULL) {
1414 		if (!*p)
1415 			continue;
1416 
1417 		token = match_token(p, srp_opt_tokens, args);
1418 		opt_mask |= token;
1419 
1420 		switch (token) {
1421 		case SRP_OPT_ID_EXT:
1422 			p = match_strdup(args);
1423 			target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
1424 			kfree(p);
1425 			break;
1426 
1427 		case SRP_OPT_IOC_GUID:
1428 			p = match_strdup(args);
1429 			target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
1430 			kfree(p);
1431 			break;
1432 
1433 		case SRP_OPT_DGID:
1434 			p = match_strdup(args);
1435 			if (strlen(p) != 32) {
1436 				printk(KERN_WARNING PFX "bad dest GID parameter '%s'\n", p);
1437 				goto out;
1438 			}
1439 
1440 			for (i = 0; i < 16; ++i) {
1441 				strlcpy(dgid, p + i * 2, 3);
1442 				target->path.dgid.raw[i] = simple_strtoul(dgid, NULL, 16);
1443 			}
1444 			kfree(p);
1445 			break;
1446 
1447 		case SRP_OPT_PKEY:
1448 			if (match_hex(args, &token)) {
1449 				printk(KERN_WARNING PFX "bad P_Key parameter '%s'\n", p);
1450 				goto out;
1451 			}
1452 			target->path.pkey = cpu_to_be16(token);
1453 			break;
1454 
1455 		case SRP_OPT_SERVICE_ID:
1456 			p = match_strdup(args);
1457 			target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
1458 			kfree(p);
1459 			break;
1460 
1461 		case SRP_OPT_MAX_SECT:
1462 			if (match_int(args, &token)) {
1463 				printk(KERN_WARNING PFX "bad max sect parameter '%s'\n", p);
1464 				goto out;
1465 			}
1466 			target->scsi_host->max_sectors = token;
1467 			break;
1468 
1469 		default:
1470 			printk(KERN_WARNING PFX "unknown parameter or missing value "
1471 			       "'%s' in target creation request\n", p);
1472 			goto out;
1473 		}
1474 	}
1475 
1476 	if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
1477 		ret = 0;
1478 	else
1479 		for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
1480 			if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
1481 			    !(srp_opt_tokens[i].token & opt_mask))
1482 				printk(KERN_WARNING PFX "target creation request is "
1483 				       "missing parameter '%s'\n",
1484 				       srp_opt_tokens[i].pattern);
1485 
1486 out:
1487 	kfree(options);
1488 	return ret;
1489 }
1490 
1491 static ssize_t srp_create_target(struct class_device *class_dev,
1492 				 const char *buf, size_t count)
1493 {
1494 	struct srp_host *host =
1495 		container_of(class_dev, struct srp_host, class_dev);
1496 	struct Scsi_Host *target_host;
1497 	struct srp_target_port *target;
1498 	int ret;
1499 	int i;
1500 
1501 	target_host = scsi_host_alloc(&srp_template,
1502 				      sizeof (struct srp_target_port));
1503 	if (!target_host)
1504 		return -ENOMEM;
1505 
1506 	target_host->max_lun = SRP_MAX_LUN;
1507 
1508 	target = host_to_target(target_host);
1509 	memset(target, 0, sizeof *target);
1510 
1511 	target->scsi_host  = target_host;
1512 	target->srp_host   = host;
1513 
1514 	INIT_WORK(&target->work, srp_reconnect_work, target);
1515 
1516 	for (i = 0; i < SRP_SQ_SIZE - 1; ++i)
1517 		target->req_ring[i].next = i + 1;
1518 	target->req_ring[SRP_SQ_SIZE - 1].next = -1;
1519 	INIT_LIST_HEAD(&target->req_queue);
1520 
1521 	ret = srp_parse_options(buf, target);
1522 	if (ret)
1523 		goto err;
1524 
1525 	ib_get_cached_gid(host->dev, host->port, 0, &target->path.sgid);
1526 
1527 	printk(KERN_DEBUG PFX "new target: id_ext %016llx ioc_guid %016llx pkey %04x "
1528 	       "service_id %016llx dgid %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
1529 	       (unsigned long long) be64_to_cpu(target->id_ext),
1530 	       (unsigned long long) be64_to_cpu(target->ioc_guid),
1531 	       be16_to_cpu(target->path.pkey),
1532 	       (unsigned long long) be64_to_cpu(target->service_id),
1533 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[0]),
1534 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[2]),
1535 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[4]),
1536 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[6]),
1537 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[8]),
1538 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[10]),
1539 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[12]),
1540 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[14]));
1541 
1542 	ret = srp_create_target_ib(target);
1543 	if (ret)
1544 		goto err;
1545 
1546 	target->cm_id = ib_create_cm_id(host->dev, srp_cm_handler, target);
1547 	if (IS_ERR(target->cm_id)) {
1548 		ret = PTR_ERR(target->cm_id);
1549 		goto err_free;
1550 	}
1551 
1552 	ret = srp_connect_target(target);
1553 	if (ret) {
1554 		printk(KERN_ERR PFX "Connection failed\n");
1555 		goto err_cm_id;
1556 	}
1557 
1558 	ret = srp_add_target(host, target);
1559 	if (ret)
1560 		goto err_disconnect;
1561 
1562 	return count;
1563 
1564 err_disconnect:
1565 	srp_disconnect_target(target);
1566 
1567 err_cm_id:
1568 	ib_destroy_cm_id(target->cm_id);
1569 
1570 err_free:
1571 	srp_free_target_ib(target);
1572 
1573 err:
1574 	scsi_host_put(target_host);
1575 
1576 	return ret;
1577 }
1578 
1579 static CLASS_DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
1580 
1581 static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
1582 {
1583 	struct srp_host *host =
1584 		container_of(class_dev, struct srp_host, class_dev);
1585 
1586 	return sprintf(buf, "%s\n", host->dev->name);
1587 }
1588 
1589 static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
1590 
1591 static ssize_t show_port(struct class_device *class_dev, char *buf)
1592 {
1593 	struct srp_host *host =
1594 		container_of(class_dev, struct srp_host, class_dev);
1595 
1596 	return sprintf(buf, "%d\n", host->port);
1597 }
1598 
1599 static CLASS_DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
1600 
1601 static struct srp_host *srp_add_port(struct ib_device *device, u8 port)
1602 {
1603 	struct srp_host *host;
1604 
1605 	host = kzalloc(sizeof *host, GFP_KERNEL);
1606 	if (!host)
1607 		return NULL;
1608 
1609 	INIT_LIST_HEAD(&host->target_list);
1610 	mutex_init(&host->target_mutex);
1611 	init_completion(&host->released);
1612 	host->dev  = device;
1613 	host->port = port;
1614 
1615 	host->initiator_port_id[7] = port;
1616 	memcpy(host->initiator_port_id + 8, &device->node_guid, 8);
1617 
1618 	host->pd   = ib_alloc_pd(device);
1619 	if (IS_ERR(host->pd))
1620 		goto err_free;
1621 
1622 	host->mr   = ib_get_dma_mr(host->pd,
1623 				   IB_ACCESS_LOCAL_WRITE |
1624 				   IB_ACCESS_REMOTE_READ |
1625 				   IB_ACCESS_REMOTE_WRITE);
1626 	if (IS_ERR(host->mr))
1627 		goto err_pd;
1628 
1629 	host->class_dev.class = &srp_class;
1630 	host->class_dev.dev   = device->dma_device;
1631 	snprintf(host->class_dev.class_id, BUS_ID_SIZE, "srp-%s-%d",
1632 		 device->name, port);
1633 
1634 	if (class_device_register(&host->class_dev))
1635 		goto err_mr;
1636 	if (class_device_create_file(&host->class_dev, &class_device_attr_add_target))
1637 		goto err_class;
1638 	if (class_device_create_file(&host->class_dev, &class_device_attr_ibdev))
1639 		goto err_class;
1640 	if (class_device_create_file(&host->class_dev, &class_device_attr_port))
1641 		goto err_class;
1642 
1643 	return host;
1644 
1645 err_class:
1646 	class_device_unregister(&host->class_dev);
1647 
1648 err_mr:
1649 	ib_dereg_mr(host->mr);
1650 
1651 err_pd:
1652 	ib_dealloc_pd(host->pd);
1653 
1654 err_free:
1655 	kfree(host);
1656 
1657 	return NULL;
1658 }
1659 
1660 static void srp_add_one(struct ib_device *device)
1661 {
1662 	struct list_head *dev_list;
1663 	struct srp_host *host;
1664 	int s, e, p;
1665 
1666 	dev_list = kmalloc(sizeof *dev_list, GFP_KERNEL);
1667 	if (!dev_list)
1668 		return;
1669 
1670 	INIT_LIST_HEAD(dev_list);
1671 
1672 	if (device->node_type == IB_NODE_SWITCH) {
1673 		s = 0;
1674 		e = 0;
1675 	} else {
1676 		s = 1;
1677 		e = device->phys_port_cnt;
1678 	}
1679 
1680 	for (p = s; p <= e; ++p) {
1681 		host = srp_add_port(device, p);
1682 		if (host)
1683 			list_add_tail(&host->list, dev_list);
1684 	}
1685 
1686 	ib_set_client_data(device, &srp_client, dev_list);
1687 }
1688 
1689 static void srp_remove_one(struct ib_device *device)
1690 {
1691 	struct list_head *dev_list;
1692 	struct srp_host *host, *tmp_host;
1693 	LIST_HEAD(target_list);
1694 	struct srp_target_port *target, *tmp_target;
1695 	unsigned long flags;
1696 
1697 	dev_list = ib_get_client_data(device, &srp_client);
1698 
1699 	list_for_each_entry_safe(host, tmp_host, dev_list, list) {
1700 		class_device_unregister(&host->class_dev);
1701 		/*
1702 		 * Wait for the sysfs entry to go away, so that no new
1703 		 * target ports can be created.
1704 		 */
1705 		wait_for_completion(&host->released);
1706 
1707 		/*
1708 		 * Mark all target ports as removed, so we stop queueing
1709 		 * commands and don't try to reconnect.
1710 		 */
1711 		mutex_lock(&host->target_mutex);
1712 		list_for_each_entry_safe(target, tmp_target,
1713 					 &host->target_list, list) {
1714 			spin_lock_irqsave(target->scsi_host->host_lock, flags);
1715 			if (target->state != SRP_TARGET_REMOVED)
1716 				target->state = SRP_TARGET_REMOVED;
1717 			spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
1718 		}
1719 		mutex_unlock(&host->target_mutex);
1720 
1721 		/*
1722 		 * Wait for any reconnection tasks that may have
1723 		 * started before we marked our target ports as
1724 		 * removed, and any target port removal tasks.
1725 		 */
1726 		flush_scheduled_work();
1727 
1728 		list_for_each_entry_safe(target, tmp_target,
1729 					 &host->target_list, list) {
1730 			scsi_remove_host(target->scsi_host);
1731 			srp_disconnect_target(target);
1732 			ib_destroy_cm_id(target->cm_id);
1733 			srp_free_target_ib(target);
1734 			scsi_host_put(target->scsi_host);
1735 		}
1736 
1737 		ib_dereg_mr(host->mr);
1738 		ib_dealloc_pd(host->pd);
1739 		kfree(host);
1740 	}
1741 
1742 	kfree(dev_list);
1743 }
1744 
1745 static int __init srp_init_module(void)
1746 {
1747 	int ret;
1748 
1749 	ret = class_register(&srp_class);
1750 	if (ret) {
1751 		printk(KERN_ERR PFX "couldn't register class infiniband_srp\n");
1752 		return ret;
1753 	}
1754 
1755 	ret = ib_register_client(&srp_client);
1756 	if (ret) {
1757 		printk(KERN_ERR PFX "couldn't register IB client\n");
1758 		class_unregister(&srp_class);
1759 		return ret;
1760 	}
1761 
1762 	return 0;
1763 }
1764 
1765 static void __exit srp_cleanup_module(void)
1766 {
1767 	ib_unregister_client(&srp_client);
1768 	class_unregister(&srp_class);
1769 }
1770 
1771 module_init(srp_init_module);
1772 module_exit(srp_cleanup_module);
1773