xref: /linux/drivers/infiniband/ulp/srp/ib_srp.c (revision 7b12b9137930eb821b68e1bfa11e9de692208620)
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_remove_req(struct srp_target_port *target, struct srp_request *req,
621 			   int index)
622 {
623 	list_del(&req->list);
624 	req->next = target->req_head;
625 	target->req_head = index;
626 }
627 
628 static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
629 {
630 	struct srp_request *req;
631 	struct scsi_cmnd *scmnd;
632 	unsigned long flags;
633 	s32 delta;
634 
635 	delta = (s32) be32_to_cpu(rsp->req_lim_delta);
636 
637 	spin_lock_irqsave(target->scsi_host->host_lock, flags);
638 
639 	target->req_lim += delta;
640 
641 	req = &target->req_ring[rsp->tag & ~SRP_TAG_TSK_MGMT];
642 
643 	if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
644 		if (be32_to_cpu(rsp->resp_data_len) < 4)
645 			req->tsk_status = -1;
646 		else
647 			req->tsk_status = rsp->data[3];
648 		complete(&req->done);
649 	} else {
650 		scmnd 	      = req->scmnd;
651 		if (!scmnd)
652 			printk(KERN_ERR "Null scmnd for RSP w/tag %016llx\n",
653 			       (unsigned long long) rsp->tag);
654 		scmnd->result = rsp->status;
655 
656 		if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
657 			memcpy(scmnd->sense_buffer, rsp->data +
658 			       be32_to_cpu(rsp->resp_data_len),
659 			       min_t(int, be32_to_cpu(rsp->sense_data_len),
660 				     SCSI_SENSE_BUFFERSIZE));
661 		}
662 
663 		if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
664 			scmnd->resid = be32_to_cpu(rsp->data_out_res_cnt);
665 		else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
666 			scmnd->resid = be32_to_cpu(rsp->data_in_res_cnt);
667 
668 		srp_unmap_data(scmnd, target, req);
669 
670 		if (!req->tsk_mgmt) {
671 			req->scmnd = NULL;
672 			scmnd->host_scribble = (void *) -1L;
673 			scmnd->scsi_done(scmnd);
674 
675 			srp_remove_req(target, req, 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 (target->state == SRP_TARGET_DEAD ||
1158 	    target->state == SRP_TARGET_REMOVED) {
1159 		scmnd->result = DID_BAD_TARGET << 16;
1160 		goto out;
1161 	}
1162 
1163 	if (scmnd->host_scribble == (void *) -1L)
1164 		goto out;
1165 
1166 	req_index = (long) scmnd->host_scribble;
1167 	printk(KERN_ERR "Abort for req_index %d\n", req_index);
1168 
1169 	req = &target->req_ring[req_index];
1170 	init_completion(&req->done);
1171 
1172 	iu = __srp_get_tx_iu(target);
1173 	if (!iu)
1174 		goto out;
1175 
1176 	tsk_mgmt = iu->buf;
1177 	memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
1178 
1179 	tsk_mgmt->opcode 	= SRP_TSK_MGMT;
1180 	tsk_mgmt->lun 		= cpu_to_be64((u64) scmnd->device->lun << 48);
1181 	tsk_mgmt->tag 		= req_index | SRP_TAG_TSK_MGMT;
1182 	tsk_mgmt->tsk_mgmt_func = func;
1183 	tsk_mgmt->task_tag 	= req_index;
1184 
1185 	if (__srp_post_send(target, iu, sizeof *tsk_mgmt))
1186 		goto out;
1187 
1188 	req->tsk_mgmt = iu;
1189 
1190 	spin_unlock_irq(target->scsi_host->host_lock);
1191 	if (!wait_for_completion_timeout(&req->done,
1192 					 msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
1193 		return FAILED;
1194 	spin_lock_irq(target->scsi_host->host_lock);
1195 
1196 	if (req->cmd_done) {
1197 		srp_remove_req(target, req, req_index);
1198 		scmnd->scsi_done(scmnd);
1199 	} else if (!req->tsk_status) {
1200 		srp_remove_req(target, req, req_index);
1201 		scmnd->result = DID_ABORT << 16;
1202 		ret = SUCCESS;
1203 	}
1204 
1205 out:
1206 	spin_unlock_irq(target->scsi_host->host_lock);
1207 	return ret;
1208 }
1209 
1210 static int srp_abort(struct scsi_cmnd *scmnd)
1211 {
1212 	printk(KERN_ERR "SRP abort called\n");
1213 
1214 	return srp_send_tsk_mgmt(scmnd, SRP_TSK_ABORT_TASK);
1215 }
1216 
1217 static int srp_reset_device(struct scsi_cmnd *scmnd)
1218 {
1219 	printk(KERN_ERR "SRP reset_device called\n");
1220 
1221 	return srp_send_tsk_mgmt(scmnd, SRP_TSK_LUN_RESET);
1222 }
1223 
1224 static int srp_reset_host(struct scsi_cmnd *scmnd)
1225 {
1226 	struct srp_target_port *target = host_to_target(scmnd->device->host);
1227 	int ret = FAILED;
1228 
1229 	printk(KERN_ERR PFX "SRP reset_host called\n");
1230 
1231 	if (!srp_reconnect_target(target))
1232 		ret = SUCCESS;
1233 
1234 	return ret;
1235 }
1236 
1237 static ssize_t show_id_ext(struct class_device *cdev, char *buf)
1238 {
1239 	struct srp_target_port *target = host_to_target(class_to_shost(cdev));
1240 
1241 	if (target->state == SRP_TARGET_DEAD ||
1242 	    target->state == SRP_TARGET_REMOVED)
1243 		return -ENODEV;
1244 
1245 	return sprintf(buf, "0x%016llx\n",
1246 		       (unsigned long long) be64_to_cpu(target->id_ext));
1247 }
1248 
1249 static ssize_t show_ioc_guid(struct class_device *cdev, char *buf)
1250 {
1251 	struct srp_target_port *target = host_to_target(class_to_shost(cdev));
1252 
1253 	if (target->state == SRP_TARGET_DEAD ||
1254 	    target->state == SRP_TARGET_REMOVED)
1255 		return -ENODEV;
1256 
1257 	return sprintf(buf, "0x%016llx\n",
1258 		       (unsigned long long) be64_to_cpu(target->ioc_guid));
1259 }
1260 
1261 static ssize_t show_service_id(struct class_device *cdev, char *buf)
1262 {
1263 	struct srp_target_port *target = host_to_target(class_to_shost(cdev));
1264 
1265 	if (target->state == SRP_TARGET_DEAD ||
1266 	    target->state == SRP_TARGET_REMOVED)
1267 		return -ENODEV;
1268 
1269 	return sprintf(buf, "0x%016llx\n",
1270 		       (unsigned long long) be64_to_cpu(target->service_id));
1271 }
1272 
1273 static ssize_t show_pkey(struct class_device *cdev, char *buf)
1274 {
1275 	struct srp_target_port *target = host_to_target(class_to_shost(cdev));
1276 
1277 	if (target->state == SRP_TARGET_DEAD ||
1278 	    target->state == SRP_TARGET_REMOVED)
1279 		return -ENODEV;
1280 
1281 	return sprintf(buf, "0x%04x\n", be16_to_cpu(target->path.pkey));
1282 }
1283 
1284 static ssize_t show_dgid(struct class_device *cdev, char *buf)
1285 {
1286 	struct srp_target_port *target = host_to_target(class_to_shost(cdev));
1287 
1288 	if (target->state == SRP_TARGET_DEAD ||
1289 	    target->state == SRP_TARGET_REMOVED)
1290 		return -ENODEV;
1291 
1292 	return sprintf(buf, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
1293 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[0]),
1294 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[1]),
1295 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[2]),
1296 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[3]),
1297 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[4]),
1298 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[5]),
1299 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[6]),
1300 		       be16_to_cpu(((__be16 *) target->path.dgid.raw)[7]));
1301 }
1302 
1303 static CLASS_DEVICE_ATTR(id_ext,	S_IRUGO, show_id_ext,		NULL);
1304 static CLASS_DEVICE_ATTR(ioc_guid,	S_IRUGO, show_ioc_guid,		NULL);
1305 static CLASS_DEVICE_ATTR(service_id,	S_IRUGO, show_service_id,	NULL);
1306 static CLASS_DEVICE_ATTR(pkey,		S_IRUGO, show_pkey,		NULL);
1307 static CLASS_DEVICE_ATTR(dgid,		S_IRUGO, show_dgid,		NULL);
1308 
1309 static struct class_device_attribute *srp_host_attrs[] = {
1310 	&class_device_attr_id_ext,
1311 	&class_device_attr_ioc_guid,
1312 	&class_device_attr_service_id,
1313 	&class_device_attr_pkey,
1314 	&class_device_attr_dgid,
1315 	NULL
1316 };
1317 
1318 static struct scsi_host_template srp_template = {
1319 	.module				= THIS_MODULE,
1320 	.name				= DRV_NAME,
1321 	.info				= srp_target_info,
1322 	.queuecommand			= srp_queuecommand,
1323 	.eh_abort_handler		= srp_abort,
1324 	.eh_device_reset_handler	= srp_reset_device,
1325 	.eh_host_reset_handler		= srp_reset_host,
1326 	.can_queue			= SRP_SQ_SIZE,
1327 	.this_id			= -1,
1328 	.sg_tablesize			= SRP_MAX_INDIRECT,
1329 	.cmd_per_lun			= SRP_SQ_SIZE,
1330 	.use_clustering			= ENABLE_CLUSTERING,
1331 	.shost_attrs			= srp_host_attrs
1332 };
1333 
1334 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
1335 {
1336 	sprintf(target->target_name, "SRP.T10:%016llX",
1337 		 (unsigned long long) be64_to_cpu(target->id_ext));
1338 
1339 	if (scsi_add_host(target->scsi_host, host->dev->dma_device))
1340 		return -ENODEV;
1341 
1342 	mutex_lock(&host->target_mutex);
1343 	list_add_tail(&target->list, &host->target_list);
1344 	mutex_unlock(&host->target_mutex);
1345 
1346 	target->state = SRP_TARGET_LIVE;
1347 
1348 	/* XXX: are we supposed to have a definition of SCAN_WILD_CARD ?? */
1349 	scsi_scan_target(&target->scsi_host->shost_gendev,
1350 			 0, target->scsi_id, ~0, 0);
1351 
1352 	return 0;
1353 }
1354 
1355 static void srp_release_class_dev(struct class_device *class_dev)
1356 {
1357 	struct srp_host *host =
1358 		container_of(class_dev, struct srp_host, class_dev);
1359 
1360 	complete(&host->released);
1361 }
1362 
1363 static struct class srp_class = {
1364 	.name    = "infiniband_srp",
1365 	.release = srp_release_class_dev
1366 };
1367 
1368 /*
1369  * Target ports are added by writing
1370  *
1371  *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
1372  *     pkey=<P_Key>,service_id=<service ID>
1373  *
1374  * to the add_target sysfs attribute.
1375  */
1376 enum {
1377 	SRP_OPT_ERR		= 0,
1378 	SRP_OPT_ID_EXT		= 1 << 0,
1379 	SRP_OPT_IOC_GUID	= 1 << 1,
1380 	SRP_OPT_DGID		= 1 << 2,
1381 	SRP_OPT_PKEY		= 1 << 3,
1382 	SRP_OPT_SERVICE_ID	= 1 << 4,
1383 	SRP_OPT_MAX_SECT	= 1 << 5,
1384 	SRP_OPT_ALL		= (SRP_OPT_ID_EXT	|
1385 				   SRP_OPT_IOC_GUID	|
1386 				   SRP_OPT_DGID		|
1387 				   SRP_OPT_PKEY		|
1388 				   SRP_OPT_SERVICE_ID),
1389 };
1390 
1391 static match_table_t srp_opt_tokens = {
1392 	{ SRP_OPT_ID_EXT,	"id_ext=%s" 	},
1393 	{ SRP_OPT_IOC_GUID,	"ioc_guid=%s" 	},
1394 	{ SRP_OPT_DGID,		"dgid=%s" 	},
1395 	{ SRP_OPT_PKEY,		"pkey=%x" 	},
1396 	{ SRP_OPT_SERVICE_ID,	"service_id=%s" },
1397 	{ SRP_OPT_MAX_SECT,     "max_sect=%d" 	},
1398 	{ SRP_OPT_ERR,		NULL 		}
1399 };
1400 
1401 static int srp_parse_options(const char *buf, struct srp_target_port *target)
1402 {
1403 	char *options, *sep_opt;
1404 	char *p;
1405 	char dgid[3];
1406 	substring_t args[MAX_OPT_ARGS];
1407 	int opt_mask = 0;
1408 	int token;
1409 	int ret = -EINVAL;
1410 	int i;
1411 
1412 	options = kstrdup(buf, GFP_KERNEL);
1413 	if (!options)
1414 		return -ENOMEM;
1415 
1416 	sep_opt = options;
1417 	while ((p = strsep(&sep_opt, ",")) != NULL) {
1418 		if (!*p)
1419 			continue;
1420 
1421 		token = match_token(p, srp_opt_tokens, args);
1422 		opt_mask |= token;
1423 
1424 		switch (token) {
1425 		case SRP_OPT_ID_EXT:
1426 			p = match_strdup(args);
1427 			target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
1428 			kfree(p);
1429 			break;
1430 
1431 		case SRP_OPT_IOC_GUID:
1432 			p = match_strdup(args);
1433 			target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
1434 			kfree(p);
1435 			break;
1436 
1437 		case SRP_OPT_DGID:
1438 			p = match_strdup(args);
1439 			if (strlen(p) != 32) {
1440 				printk(KERN_WARNING PFX "bad dest GID parameter '%s'\n", p);
1441 				kfree(p);
1442 				goto out;
1443 			}
1444 
1445 			for (i = 0; i < 16; ++i) {
1446 				strlcpy(dgid, p + i * 2, 3);
1447 				target->path.dgid.raw[i] = simple_strtoul(dgid, NULL, 16);
1448 			}
1449 			kfree(p);
1450 			break;
1451 
1452 		case SRP_OPT_PKEY:
1453 			if (match_hex(args, &token)) {
1454 				printk(KERN_WARNING PFX "bad P_Key parameter '%s'\n", p);
1455 				goto out;
1456 			}
1457 			target->path.pkey = cpu_to_be16(token);
1458 			break;
1459 
1460 		case SRP_OPT_SERVICE_ID:
1461 			p = match_strdup(args);
1462 			target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
1463 			kfree(p);
1464 			break;
1465 
1466 		case SRP_OPT_MAX_SECT:
1467 			if (match_int(args, &token)) {
1468 				printk(KERN_WARNING PFX "bad max sect parameter '%s'\n", p);
1469 				goto out;
1470 			}
1471 			target->scsi_host->max_sectors = token;
1472 			break;
1473 
1474 		default:
1475 			printk(KERN_WARNING PFX "unknown parameter or missing value "
1476 			       "'%s' in target creation request\n", p);
1477 			goto out;
1478 		}
1479 	}
1480 
1481 	if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
1482 		ret = 0;
1483 	else
1484 		for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
1485 			if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
1486 			    !(srp_opt_tokens[i].token & opt_mask))
1487 				printk(KERN_WARNING PFX "target creation request is "
1488 				       "missing parameter '%s'\n",
1489 				       srp_opt_tokens[i].pattern);
1490 
1491 out:
1492 	kfree(options);
1493 	return ret;
1494 }
1495 
1496 static ssize_t srp_create_target(struct class_device *class_dev,
1497 				 const char *buf, size_t count)
1498 {
1499 	struct srp_host *host =
1500 		container_of(class_dev, struct srp_host, class_dev);
1501 	struct Scsi_Host *target_host;
1502 	struct srp_target_port *target;
1503 	int ret;
1504 	int i;
1505 
1506 	target_host = scsi_host_alloc(&srp_template,
1507 				      sizeof (struct srp_target_port));
1508 	if (!target_host)
1509 		return -ENOMEM;
1510 
1511 	target_host->max_lun = SRP_MAX_LUN;
1512 
1513 	target = host_to_target(target_host);
1514 	memset(target, 0, sizeof *target);
1515 
1516 	target->scsi_host  = target_host;
1517 	target->srp_host   = host;
1518 
1519 	INIT_WORK(&target->work, srp_reconnect_work, target);
1520 
1521 	for (i = 0; i < SRP_SQ_SIZE - 1; ++i)
1522 		target->req_ring[i].next = i + 1;
1523 	target->req_ring[SRP_SQ_SIZE - 1].next = -1;
1524 	INIT_LIST_HEAD(&target->req_queue);
1525 
1526 	ret = srp_parse_options(buf, target);
1527 	if (ret)
1528 		goto err;
1529 
1530 	ib_get_cached_gid(host->dev, host->port, 0, &target->path.sgid);
1531 
1532 	printk(KERN_DEBUG PFX "new target: id_ext %016llx ioc_guid %016llx pkey %04x "
1533 	       "service_id %016llx dgid %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
1534 	       (unsigned long long) be64_to_cpu(target->id_ext),
1535 	       (unsigned long long) be64_to_cpu(target->ioc_guid),
1536 	       be16_to_cpu(target->path.pkey),
1537 	       (unsigned long long) be64_to_cpu(target->service_id),
1538 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[0]),
1539 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[2]),
1540 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[4]),
1541 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[6]),
1542 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[8]),
1543 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[10]),
1544 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[12]),
1545 	       (int) be16_to_cpu(*(__be16 *) &target->path.dgid.raw[14]));
1546 
1547 	ret = srp_create_target_ib(target);
1548 	if (ret)
1549 		goto err;
1550 
1551 	target->cm_id = ib_create_cm_id(host->dev, srp_cm_handler, target);
1552 	if (IS_ERR(target->cm_id)) {
1553 		ret = PTR_ERR(target->cm_id);
1554 		goto err_free;
1555 	}
1556 
1557 	ret = srp_connect_target(target);
1558 	if (ret) {
1559 		printk(KERN_ERR PFX "Connection failed\n");
1560 		goto err_cm_id;
1561 	}
1562 
1563 	ret = srp_add_target(host, target);
1564 	if (ret)
1565 		goto err_disconnect;
1566 
1567 	return count;
1568 
1569 err_disconnect:
1570 	srp_disconnect_target(target);
1571 
1572 err_cm_id:
1573 	ib_destroy_cm_id(target->cm_id);
1574 
1575 err_free:
1576 	srp_free_target_ib(target);
1577 
1578 err:
1579 	scsi_host_put(target_host);
1580 
1581 	return ret;
1582 }
1583 
1584 static CLASS_DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
1585 
1586 static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
1587 {
1588 	struct srp_host *host =
1589 		container_of(class_dev, struct srp_host, class_dev);
1590 
1591 	return sprintf(buf, "%s\n", host->dev->name);
1592 }
1593 
1594 static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
1595 
1596 static ssize_t show_port(struct class_device *class_dev, char *buf)
1597 {
1598 	struct srp_host *host =
1599 		container_of(class_dev, struct srp_host, class_dev);
1600 
1601 	return sprintf(buf, "%d\n", host->port);
1602 }
1603 
1604 static CLASS_DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
1605 
1606 static struct srp_host *srp_add_port(struct ib_device *device, u8 port)
1607 {
1608 	struct srp_host *host;
1609 
1610 	host = kzalloc(sizeof *host, GFP_KERNEL);
1611 	if (!host)
1612 		return NULL;
1613 
1614 	INIT_LIST_HEAD(&host->target_list);
1615 	mutex_init(&host->target_mutex);
1616 	init_completion(&host->released);
1617 	host->dev  = device;
1618 	host->port = port;
1619 
1620 	host->initiator_port_id[7] = port;
1621 	memcpy(host->initiator_port_id + 8, &device->node_guid, 8);
1622 
1623 	host->pd   = ib_alloc_pd(device);
1624 	if (IS_ERR(host->pd))
1625 		goto err_free;
1626 
1627 	host->mr   = ib_get_dma_mr(host->pd,
1628 				   IB_ACCESS_LOCAL_WRITE |
1629 				   IB_ACCESS_REMOTE_READ |
1630 				   IB_ACCESS_REMOTE_WRITE);
1631 	if (IS_ERR(host->mr))
1632 		goto err_pd;
1633 
1634 	host->class_dev.class = &srp_class;
1635 	host->class_dev.dev   = device->dma_device;
1636 	snprintf(host->class_dev.class_id, BUS_ID_SIZE, "srp-%s-%d",
1637 		 device->name, port);
1638 
1639 	if (class_device_register(&host->class_dev))
1640 		goto err_mr;
1641 	if (class_device_create_file(&host->class_dev, &class_device_attr_add_target))
1642 		goto err_class;
1643 	if (class_device_create_file(&host->class_dev, &class_device_attr_ibdev))
1644 		goto err_class;
1645 	if (class_device_create_file(&host->class_dev, &class_device_attr_port))
1646 		goto err_class;
1647 
1648 	return host;
1649 
1650 err_class:
1651 	class_device_unregister(&host->class_dev);
1652 
1653 err_mr:
1654 	ib_dereg_mr(host->mr);
1655 
1656 err_pd:
1657 	ib_dealloc_pd(host->pd);
1658 
1659 err_free:
1660 	kfree(host);
1661 
1662 	return NULL;
1663 }
1664 
1665 static void srp_add_one(struct ib_device *device)
1666 {
1667 	struct list_head *dev_list;
1668 	struct srp_host *host;
1669 	int s, e, p;
1670 
1671 	dev_list = kmalloc(sizeof *dev_list, GFP_KERNEL);
1672 	if (!dev_list)
1673 		return;
1674 
1675 	INIT_LIST_HEAD(dev_list);
1676 
1677 	if (device->node_type == IB_NODE_SWITCH) {
1678 		s = 0;
1679 		e = 0;
1680 	} else {
1681 		s = 1;
1682 		e = device->phys_port_cnt;
1683 	}
1684 
1685 	for (p = s; p <= e; ++p) {
1686 		host = srp_add_port(device, p);
1687 		if (host)
1688 			list_add_tail(&host->list, dev_list);
1689 	}
1690 
1691 	ib_set_client_data(device, &srp_client, dev_list);
1692 }
1693 
1694 static void srp_remove_one(struct ib_device *device)
1695 {
1696 	struct list_head *dev_list;
1697 	struct srp_host *host, *tmp_host;
1698 	LIST_HEAD(target_list);
1699 	struct srp_target_port *target, *tmp_target;
1700 	unsigned long flags;
1701 
1702 	dev_list = ib_get_client_data(device, &srp_client);
1703 
1704 	list_for_each_entry_safe(host, tmp_host, dev_list, list) {
1705 		class_device_unregister(&host->class_dev);
1706 		/*
1707 		 * Wait for the sysfs entry to go away, so that no new
1708 		 * target ports can be created.
1709 		 */
1710 		wait_for_completion(&host->released);
1711 
1712 		/*
1713 		 * Mark all target ports as removed, so we stop queueing
1714 		 * commands and don't try to reconnect.
1715 		 */
1716 		mutex_lock(&host->target_mutex);
1717 		list_for_each_entry_safe(target, tmp_target,
1718 					 &host->target_list, list) {
1719 			spin_lock_irqsave(target->scsi_host->host_lock, flags);
1720 			if (target->state != SRP_TARGET_REMOVED)
1721 				target->state = SRP_TARGET_REMOVED;
1722 			spin_unlock_irqrestore(target->scsi_host->host_lock, flags);
1723 		}
1724 		mutex_unlock(&host->target_mutex);
1725 
1726 		/*
1727 		 * Wait for any reconnection tasks that may have
1728 		 * started before we marked our target ports as
1729 		 * removed, and any target port removal tasks.
1730 		 */
1731 		flush_scheduled_work();
1732 
1733 		list_for_each_entry_safe(target, tmp_target,
1734 					 &host->target_list, list) {
1735 			scsi_remove_host(target->scsi_host);
1736 			srp_disconnect_target(target);
1737 			ib_destroy_cm_id(target->cm_id);
1738 			srp_free_target_ib(target);
1739 			scsi_host_put(target->scsi_host);
1740 		}
1741 
1742 		ib_dereg_mr(host->mr);
1743 		ib_dealloc_pd(host->pd);
1744 		kfree(host);
1745 	}
1746 
1747 	kfree(dev_list);
1748 }
1749 
1750 static int __init srp_init_module(void)
1751 {
1752 	int ret;
1753 
1754 	ret = class_register(&srp_class);
1755 	if (ret) {
1756 		printk(KERN_ERR PFX "couldn't register class infiniband_srp\n");
1757 		return ret;
1758 	}
1759 
1760 	ret = ib_register_client(&srp_client);
1761 	if (ret) {
1762 		printk(KERN_ERR PFX "couldn't register IB client\n");
1763 		class_unregister(&srp_class);
1764 		return ret;
1765 	}
1766 
1767 	return 0;
1768 }
1769 
1770 static void __exit srp_cleanup_module(void)
1771 {
1772 	ib_unregister_client(&srp_client);
1773 	class_unregister(&srp_class);
1774 }
1775 
1776 module_init(srp_init_module);
1777 module_exit(srp_cleanup_module);
1778