1 /*
2  * iSCSI Initiator over iSER Data-Path
3  *
4  * Copyright (C) 2004 Dmitry Yusupov
5  * Copyright (C) 2004 Alex Aizman
6  * Copyright (C) 2005 Mike Christie
7  * Copyright (c) 2005, 2006 Voltaire, Inc. All rights reserved.
8  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
9  * maintained by openib-general@openib.org
10  *
11  * This software is available to you under a choice of one of two
12  * licenses.  You may choose to be licensed under the terms of the GNU
13  * General Public License (GPL) Version 2, available from the file
14  * COPYING in the main directory of this source tree, or the
15  * OpenIB.org BSD license below:
16  *
17  *     Redistribution and use in source and binary forms, with or
18  *     without modification, are permitted provided that the following
19  *     conditions are met:
20  *
21  *	- Redistributions of source code must retain the above
22  *	  copyright notice, this list of conditions and the following
23  *	  disclaimer.
24  *
25  *	- Redistributions in binary form must reproduce the above
26  *	  copyright notice, this list of conditions and the following
27  *	  disclaimer in the documentation and/or other materials
28  *	  provided with the distribution.
29  *
30  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
31  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
32  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
33  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
34  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
35  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
36  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
37  * SOFTWARE.
38  *
39  * Credits:
40  *	Christoph Hellwig
41  *	FUJITA Tomonori
42  *	Arne Redlich
43  *	Zhenyu Wang
44  * Modified by:
45  *      Erez Zilber
46  */
47 
48 #include <linux/types.h>
49 #include <linux/list.h>
50 #include <linux/hardirq.h>
51 #include <linux/kfifo.h>
52 #include <linux/blkdev.h>
53 #include <linux/init.h>
54 #include <linux/ioctl.h>
55 #include <linux/cdev.h>
56 #include <linux/in.h>
57 #include <linux/net.h>
58 #include <linux/scatterlist.h>
59 #include <linux/delay.h>
60 #include <linux/slab.h>
61 #include <linux/module.h>
62 
63 #include <net/sock.h>
64 
65 #include <asm/uaccess.h>
66 
67 #include <scsi/scsi_cmnd.h>
68 #include <scsi/scsi_device.h>
69 #include <scsi/scsi_eh.h>
70 #include <scsi/scsi_tcq.h>
71 #include <scsi/scsi_host.h>
72 #include <scsi/scsi.h>
73 #include <scsi/scsi_transport_iscsi.h>
74 
75 #include "iscsi_iser.h"
76 
77 static struct scsi_host_template iscsi_iser_sht;
78 static struct iscsi_transport iscsi_iser_transport;
79 static struct scsi_transport_template *iscsi_iser_scsi_transport;
80 
81 static unsigned int iscsi_max_lun = 512;
82 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
83 
84 int iser_debug_level = 0;
85 bool iser_pi_enable = false;
86 int iser_pi_guard = 0;
87 
88 MODULE_DESCRIPTION("iSER (iSCSI Extensions for RDMA) Datamover");
89 MODULE_LICENSE("Dual BSD/GPL");
90 MODULE_AUTHOR("Alex Nezhinsky, Dan Bar Dov, Or Gerlitz");
91 MODULE_VERSION(DRV_VER);
92 
93 module_param_named(debug_level, iser_debug_level, int, 0644);
94 MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:disabled)");
95 
96 module_param_named(pi_enable, iser_pi_enable, bool, 0644);
97 MODULE_PARM_DESC(pi_enable, "Enable T10-PI offload support (default:disabled)");
98 
99 module_param_named(pi_guard, iser_pi_guard, int, 0644);
100 MODULE_PARM_DESC(pi_guard, "T10-PI guard_type, 0:CRC|1:IP_CSUM (default:CRC)");
101 
102 static struct workqueue_struct *release_wq;
103 struct iser_global ig;
104 
105 void
106 iscsi_iser_recv(struct iscsi_conn *conn,
107 		struct iscsi_hdr *hdr, char *rx_data, int rx_data_len)
108 {
109 	int rc = 0;
110 	int datalen;
111 	int ahslen;
112 
113 	/* verify PDU length */
114 	datalen = ntoh24(hdr->dlength);
115 	if (datalen > rx_data_len || (datalen + 4) < rx_data_len) {
116 		iser_err("wrong datalen %d (hdr), %d (IB)\n",
117 			datalen, rx_data_len);
118 		rc = ISCSI_ERR_DATALEN;
119 		goto error;
120 	}
121 
122 	if (datalen != rx_data_len)
123 		iser_dbg("aligned datalen (%d) hdr, %d (IB)\n",
124 			datalen, rx_data_len);
125 
126 	/* read AHS */
127 	ahslen = hdr->hlength * 4;
128 
129 	rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
130 	if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
131 		goto error;
132 
133 	return;
134 error:
135 	iscsi_conn_failure(conn, rc);
136 }
137 
138 static int iscsi_iser_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
139 {
140 	struct iscsi_iser_task *iser_task = task->dd_data;
141 
142 	task->hdr = (struct iscsi_hdr *)&iser_task->desc.iscsi_header;
143 	task->hdr_max = sizeof(iser_task->desc.iscsi_header);
144 	return 0;
145 }
146 
147 int iser_initialize_task_headers(struct iscsi_task *task,
148 						struct iser_tx_desc *tx_desc)
149 {
150 	struct iser_conn       *ib_conn   = task->conn->dd_data;
151 	struct iser_device     *device    = ib_conn->device;
152 	struct iscsi_iser_task *iser_task = task->dd_data;
153 	u64 dma_addr;
154 
155 	dma_addr = ib_dma_map_single(device->ib_device, (void *)tx_desc,
156 				ISER_HEADERS_LEN, DMA_TO_DEVICE);
157 	if (ib_dma_mapping_error(device->ib_device, dma_addr))
158 		return -ENOMEM;
159 
160 	tx_desc->dma_addr = dma_addr;
161 	tx_desc->tx_sg[0].addr   = tx_desc->dma_addr;
162 	tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;
163 	tx_desc->tx_sg[0].lkey   = device->mr->lkey;
164 
165 	iser_task->ib_conn = ib_conn;
166 	return 0;
167 }
168 /**
169  * iscsi_iser_task_init - Initialize task
170  * @task: iscsi task
171  *
172  * Initialize the task for the scsi command or mgmt command.
173  */
174 static int
175 iscsi_iser_task_init(struct iscsi_task *task)
176 {
177 	struct iscsi_iser_task *iser_task = task->dd_data;
178 
179 	if (iser_initialize_task_headers(task, &iser_task->desc))
180 			return -ENOMEM;
181 
182 	/* mgmt task */
183 	if (!task->sc)
184 		return 0;
185 
186 	iser_task->command_sent = 0;
187 	iser_task_rdma_init(iser_task);
188 	iser_task->sc = task->sc;
189 
190 	return 0;
191 }
192 
193 /**
194  * iscsi_iser_mtask_xmit - xmit management(immediate) task
195  * @conn: iscsi connection
196  * @task: task management task
197  *
198  * Notes:
199  *	The function can return -EAGAIN in which case caller must
200  *	call it again later, or recover. '0' return code means successful
201  *	xmit.
202  *
203  **/
204 static int
205 iscsi_iser_mtask_xmit(struct iscsi_conn *conn, struct iscsi_task *task)
206 {
207 	int error = 0;
208 
209 	iser_dbg("mtask xmit [cid %d itt 0x%x]\n", conn->id, task->itt);
210 
211 	error = iser_send_control(conn, task);
212 
213 	/* since iser xmits control with zero copy, tasks can not be recycled
214 	 * right after sending them.
215 	 * The recycling scheme is based on whether a response is expected
216 	 * - if yes, the task is recycled at iscsi_complete_pdu
217 	 * - if no,  the task is recycled at iser_snd_completion
218 	 */
219 	return error;
220 }
221 
222 static int
223 iscsi_iser_task_xmit_unsol_data(struct iscsi_conn *conn,
224 				 struct iscsi_task *task)
225 {
226 	struct iscsi_r2t_info *r2t = &task->unsol_r2t;
227 	struct iscsi_data hdr;
228 	int error = 0;
229 
230 	/* Send data-out PDUs while there's still unsolicited data to send */
231 	while (iscsi_task_has_unsol_data(task)) {
232 		iscsi_prep_data_out_pdu(task, r2t, &hdr);
233 		iser_dbg("Sending data-out: itt 0x%x, data count %d\n",
234 			   hdr.itt, r2t->data_count);
235 
236 		/* the buffer description has been passed with the command */
237 		/* Send the command */
238 		error = iser_send_data_out(conn, task, &hdr);
239 		if (error) {
240 			r2t->datasn--;
241 			goto iscsi_iser_task_xmit_unsol_data_exit;
242 		}
243 		r2t->sent += r2t->data_count;
244 		iser_dbg("Need to send %d more as data-out PDUs\n",
245 			   r2t->data_length - r2t->sent);
246 	}
247 
248 iscsi_iser_task_xmit_unsol_data_exit:
249 	return error;
250 }
251 
252 static int
253 iscsi_iser_task_xmit(struct iscsi_task *task)
254 {
255 	struct iscsi_conn *conn = task->conn;
256 	struct iscsi_iser_task *iser_task = task->dd_data;
257 	int error = 0;
258 
259 	if (!task->sc)
260 		return iscsi_iser_mtask_xmit(conn, task);
261 
262 	if (task->sc->sc_data_direction == DMA_TO_DEVICE) {
263 		BUG_ON(scsi_bufflen(task->sc) == 0);
264 
265 		iser_dbg("cmd [itt %x total %d imm %d unsol_data %d\n",
266 			   task->itt, scsi_bufflen(task->sc),
267 			   task->imm_count, task->unsol_r2t.data_length);
268 	}
269 
270 	iser_dbg("ctask xmit [cid %d itt 0x%x]\n",
271 		   conn->id, task->itt);
272 
273 	/* Send the cmd PDU */
274 	if (!iser_task->command_sent) {
275 		error = iser_send_command(conn, task);
276 		if (error)
277 			goto iscsi_iser_task_xmit_exit;
278 		iser_task->command_sent = 1;
279 	}
280 
281 	/* Send unsolicited data-out PDU(s) if necessary */
282 	if (iscsi_task_has_unsol_data(task))
283 		error = iscsi_iser_task_xmit_unsol_data(conn, task);
284 
285  iscsi_iser_task_xmit_exit:
286 	return error;
287 }
288 
289 static void iscsi_iser_cleanup_task(struct iscsi_task *task)
290 {
291 	struct iscsi_iser_task *iser_task = task->dd_data;
292 	struct iser_tx_desc    *tx_desc   = &iser_task->desc;
293 	struct iser_conn       *ib_conn	  = task->conn->dd_data;
294 	struct iser_device     *device	  = ib_conn->device;
295 
296 	ib_dma_unmap_single(device->ib_device,
297 		tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
298 
299 	/* mgmt tasks do not need special cleanup */
300 	if (!task->sc)
301 		return;
302 
303 	if (iser_task->status == ISER_TASK_STATUS_STARTED) {
304 		iser_task->status = ISER_TASK_STATUS_COMPLETED;
305 		iser_task_rdma_finalize(iser_task);
306 	}
307 }
308 
309 static u8 iscsi_iser_check_protection(struct iscsi_task *task, sector_t *sector)
310 {
311 	struct iscsi_iser_task *iser_task = task->dd_data;
312 
313 	if (iser_task->dir[ISER_DIR_IN])
314 		return iser_check_task_pi_status(iser_task, ISER_DIR_IN,
315 						 sector);
316 	else
317 		return iser_check_task_pi_status(iser_task, ISER_DIR_OUT,
318 						 sector);
319 }
320 
321 static struct iscsi_cls_conn *
322 iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
323 {
324 	struct iscsi_conn *conn;
325 	struct iscsi_cls_conn *cls_conn;
326 
327 	cls_conn = iscsi_conn_setup(cls_session, 0, conn_idx);
328 	if (!cls_conn)
329 		return NULL;
330 	conn = cls_conn->dd_data;
331 
332 	/*
333 	 * due to issues with the login code re iser sematics
334 	 * this not set in iscsi_conn_setup - FIXME
335 	 */
336 	conn->max_recv_dlength = ISER_RECV_DATA_SEG_LEN;
337 
338 	return cls_conn;
339 }
340 
341 static int
342 iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
343 		     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
344 		     int is_leading)
345 {
346 	struct iscsi_conn *conn = cls_conn->dd_data;
347 	struct iscsi_session *session;
348 	struct iser_conn *ib_conn;
349 	struct iscsi_endpoint *ep;
350 	int error;
351 
352 	error = iscsi_conn_bind(cls_session, cls_conn, is_leading);
353 	if (error)
354 		return error;
355 
356 	/* the transport ep handle comes from user space so it must be
357 	 * verified against the global ib connections list */
358 	ep = iscsi_lookup_endpoint(transport_eph);
359 	if (!ep) {
360 		iser_err("can't bind eph %llx\n",
361 			 (unsigned long long)transport_eph);
362 		return -EINVAL;
363 	}
364 	ib_conn = ep->dd_data;
365 
366 	session = conn->session;
367 	if (iser_alloc_rx_descriptors(ib_conn, session))
368 		return -ENOMEM;
369 
370 	/* binds the iSER connection retrieved from the previously
371 	 * connected ep_handle to the iSCSI layer connection. exchanges
372 	 * connection pointers */
373 	iser_info("binding iscsi conn %p to ib_conn %p\n", conn, ib_conn);
374 
375 	conn->dd_data = ib_conn;
376 	ib_conn->iscsi_conn = conn;
377 
378 	return 0;
379 }
380 
381 static int
382 iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn)
383 {
384 	struct iscsi_conn *iscsi_conn;
385 	struct iser_conn *ib_conn;
386 
387 	iscsi_conn = cls_conn->dd_data;
388 	ib_conn = iscsi_conn->dd_data;
389 	reinit_completion(&ib_conn->stop_completion);
390 
391 	return iscsi_conn_start(cls_conn);
392 }
393 
394 static void
395 iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
396 {
397 	struct iscsi_conn *conn = cls_conn->dd_data;
398 	struct iser_conn *ib_conn = conn->dd_data;
399 
400 	iser_dbg("stopping iscsi_conn: %p, ib_conn: %p\n", conn, ib_conn);
401 	iscsi_conn_stop(cls_conn, flag);
402 
403 	/*
404 	 * Userspace may have goofed up and not bound the connection or
405 	 * might have only partially setup the connection.
406 	 */
407 	if (ib_conn) {
408 		conn->dd_data = NULL;
409 		complete(&ib_conn->stop_completion);
410 	}
411 }
412 
413 static void iscsi_iser_session_destroy(struct iscsi_cls_session *cls_session)
414 {
415 	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
416 
417 	iscsi_session_teardown(cls_session);
418 	iscsi_host_remove(shost);
419 	iscsi_host_free(shost);
420 }
421 
422 static inline unsigned int
423 iser_dif_prot_caps(int prot_caps)
424 {
425 	return ((prot_caps & IB_PROT_T10DIF_TYPE_1) ? SHOST_DIF_TYPE1_PROTECTION |
426 						      SHOST_DIX_TYPE1_PROTECTION : 0) |
427 	       ((prot_caps & IB_PROT_T10DIF_TYPE_2) ? SHOST_DIF_TYPE2_PROTECTION |
428 						      SHOST_DIX_TYPE2_PROTECTION : 0) |
429 	       ((prot_caps & IB_PROT_T10DIF_TYPE_3) ? SHOST_DIF_TYPE3_PROTECTION |
430 						      SHOST_DIX_TYPE3_PROTECTION : 0);
431 }
432 
433 static struct iscsi_cls_session *
434 iscsi_iser_session_create(struct iscsi_endpoint *ep,
435 			  uint16_t cmds_max, uint16_t qdepth,
436 			  uint32_t initial_cmdsn)
437 {
438 	struct iscsi_cls_session *cls_session;
439 	struct iscsi_session *session;
440 	struct Scsi_Host *shost;
441 	struct iser_conn *ib_conn = NULL;
442 
443 	shost = iscsi_host_alloc(&iscsi_iser_sht, 0, 0);
444 	if (!shost)
445 		return NULL;
446 	shost->transportt = iscsi_iser_scsi_transport;
447 	shost->cmd_per_lun = qdepth;
448 	shost->max_lun = iscsi_max_lun;
449 	shost->max_id = 0;
450 	shost->max_channel = 0;
451 	shost->max_cmd_len = 16;
452 
453 	/*
454 	 * older userspace tools (before 2.0-870) did not pass us
455 	 * the leading conn's ep so this will be NULL;
456 	 */
457 	if (ep) {
458 		ib_conn = ep->dd_data;
459 		if (ib_conn->pi_support) {
460 			u32 sig_caps = ib_conn->device->dev_attr.sig_prot_cap;
461 
462 			scsi_host_set_prot(shost, iser_dif_prot_caps(sig_caps));
463 			if (iser_pi_guard)
464 				scsi_host_set_guard(shost, SHOST_DIX_GUARD_IP);
465 			else
466 				scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
467 		}
468 	}
469 
470 	if (iscsi_host_add(shost,
471 			   ep ? ib_conn->device->ib_device->dma_device : NULL))
472 		goto free_host;
473 
474 	if (cmds_max > ISER_DEF_XMIT_CMDS_MAX) {
475 		iser_info("cmds_max changed from %u to %u\n",
476 			  cmds_max, ISER_DEF_XMIT_CMDS_MAX);
477 		cmds_max = ISER_DEF_XMIT_CMDS_MAX;
478 	}
479 
480 	cls_session = iscsi_session_setup(&iscsi_iser_transport, shost,
481 					  cmds_max, 0,
482 					  sizeof(struct iscsi_iser_task),
483 					  initial_cmdsn, 0);
484 	if (!cls_session)
485 		goto remove_host;
486 	session = cls_session->dd_data;
487 
488 	shost->can_queue = session->scsi_cmds_max;
489 	return cls_session;
490 
491 remove_host:
492 	iscsi_host_remove(shost);
493 free_host:
494 	iscsi_host_free(shost);
495 	return NULL;
496 }
497 
498 static int
499 iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,
500 		     enum iscsi_param param, char *buf, int buflen)
501 {
502 	int value;
503 
504 	switch (param) {
505 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
506 		/* TBD */
507 		break;
508 	case ISCSI_PARAM_HDRDGST_EN:
509 		sscanf(buf, "%d", &value);
510 		if (value) {
511 			iser_err("DataDigest wasn't negotiated to None\n");
512 			return -EPROTO;
513 		}
514 		break;
515 	case ISCSI_PARAM_DATADGST_EN:
516 		sscanf(buf, "%d", &value);
517 		if (value) {
518 			iser_err("DataDigest wasn't negotiated to None\n");
519 			return -EPROTO;
520 		}
521 		break;
522 	case ISCSI_PARAM_IFMARKER_EN:
523 		sscanf(buf, "%d", &value);
524 		if (value) {
525 			iser_err("IFMarker wasn't negotiated to No\n");
526 			return -EPROTO;
527 		}
528 		break;
529 	case ISCSI_PARAM_OFMARKER_EN:
530 		sscanf(buf, "%d", &value);
531 		if (value) {
532 			iser_err("OFMarker wasn't negotiated to No\n");
533 			return -EPROTO;
534 		}
535 		break;
536 	default:
537 		return iscsi_set_param(cls_conn, param, buf, buflen);
538 	}
539 
540 	return 0;
541 }
542 
543 static void
544 iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
545 {
546 	struct iscsi_conn *conn = cls_conn->dd_data;
547 
548 	stats->txdata_octets = conn->txdata_octets;
549 	stats->rxdata_octets = conn->rxdata_octets;
550 	stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
551 	stats->dataout_pdus = conn->dataout_pdus_cnt;
552 	stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
553 	stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */
554 	stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
555 	stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
556 	stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
557 	stats->custom_length = 4;
558 	strcpy(stats->custom[0].desc, "qp_tx_queue_full");
559 	stats->custom[0].value = 0; /* TB iser_conn->qp_tx_queue_full; */
560 	strcpy(stats->custom[1].desc, "fmr_map_not_avail");
561 	stats->custom[1].value = 0; /* TB iser_conn->fmr_map_not_avail */;
562 	strcpy(stats->custom[2].desc, "eh_abort_cnt");
563 	stats->custom[2].value = conn->eh_abort_cnt;
564 	strcpy(stats->custom[3].desc, "fmr_unalign_cnt");
565 	stats->custom[3].value = conn->fmr_unalign_cnt;
566 }
567 
568 static int iscsi_iser_get_ep_param(struct iscsi_endpoint *ep,
569 				   enum iscsi_param param, char *buf)
570 {
571 	struct iser_conn *ib_conn = ep->dd_data;
572 	int len;
573 
574 	switch (param) {
575 	case ISCSI_PARAM_CONN_PORT:
576 	case ISCSI_PARAM_CONN_ADDRESS:
577 		if (!ib_conn || !ib_conn->cma_id)
578 			return -ENOTCONN;
579 
580 		return iscsi_conn_get_addr_param((struct sockaddr_storage *)
581 					&ib_conn->cma_id->route.addr.dst_addr,
582 					param, buf);
583 		break;
584 	default:
585 		return -ENOSYS;
586 	}
587 
588 	return len;
589 }
590 
591 static struct iscsi_endpoint *
592 iscsi_iser_ep_connect(struct Scsi_Host *shost, struct sockaddr *dst_addr,
593 		      int non_blocking)
594 {
595 	int err;
596 	struct iser_conn *ib_conn;
597 	struct iscsi_endpoint *ep;
598 
599 	ep = iscsi_create_endpoint(0);
600 	if (!ep)
601 		return ERR_PTR(-ENOMEM);
602 
603 	ib_conn = kzalloc(sizeof(*ib_conn), GFP_KERNEL);
604 	if (!ib_conn) {
605 		err = -ENOMEM;
606 		goto failure;
607 	}
608 
609 	ep->dd_data = ib_conn;
610 	ib_conn->ep = ep;
611 	iser_conn_init(ib_conn);
612 
613 	err = iser_connect(ib_conn, NULL, dst_addr, non_blocking);
614 	if (err)
615 		goto failure;
616 
617 	return ep;
618 failure:
619 	iscsi_destroy_endpoint(ep);
620 	return ERR_PTR(err);
621 }
622 
623 static int
624 iscsi_iser_ep_poll(struct iscsi_endpoint *ep, int timeout_ms)
625 {
626 	struct iser_conn *ib_conn;
627 	int rc;
628 
629 	ib_conn = ep->dd_data;
630 	rc = wait_for_completion_interruptible_timeout(&ib_conn->up_completion,
631 						       msecs_to_jiffies(timeout_ms));
632 	/* if conn establishment failed, return error code to iscsi */
633 	if (rc == 0) {
634 		mutex_lock(&ib_conn->state_mutex);
635 		if (ib_conn->state == ISER_CONN_TERMINATING ||
636 		    ib_conn->state == ISER_CONN_DOWN)
637 			rc = -1;
638 		mutex_unlock(&ib_conn->state_mutex);
639 	}
640 
641 	iser_info("ib conn %p rc = %d\n", ib_conn, rc);
642 
643 	if (rc > 0)
644 		return 1; /* success, this is the equivalent of POLLOUT */
645 	else if (!rc)
646 		return 0; /* timeout */
647 	else
648 		return rc; /* signal */
649 }
650 
651 static void
652 iscsi_iser_ep_disconnect(struct iscsi_endpoint *ep)
653 {
654 	struct iser_conn *ib_conn;
655 
656 	ib_conn = ep->dd_data;
657 	iser_info("ep %p ib conn %p state %d\n", ep, ib_conn, ib_conn->state);
658 	mutex_lock(&ib_conn->state_mutex);
659 	iser_conn_terminate(ib_conn);
660 
661 	/*
662 	 * if iser_conn and iscsi_conn are bound, we must wait for
663 	 * iscsi_conn_stop and flush errors completion before freeing
664 	 * the iser resources. Otherwise we are safe to free resources
665 	 * immediately.
666 	 */
667 	if (ib_conn->iscsi_conn) {
668 		INIT_WORK(&ib_conn->release_work, iser_release_work);
669 		queue_work(release_wq, &ib_conn->release_work);
670 		mutex_unlock(&ib_conn->state_mutex);
671 	} else {
672 		ib_conn->state = ISER_CONN_DOWN;
673 		mutex_unlock(&ib_conn->state_mutex);
674 		iser_conn_release(ib_conn);
675 	}
676 	iscsi_destroy_endpoint(ep);
677 }
678 
679 static umode_t iser_attr_is_visible(int param_type, int param)
680 {
681 	switch (param_type) {
682 	case ISCSI_HOST_PARAM:
683 		switch (param) {
684 		case ISCSI_HOST_PARAM_NETDEV_NAME:
685 		case ISCSI_HOST_PARAM_HWADDRESS:
686 		case ISCSI_HOST_PARAM_INITIATOR_NAME:
687 			return S_IRUGO;
688 		default:
689 			return 0;
690 		}
691 	case ISCSI_PARAM:
692 		switch (param) {
693 		case ISCSI_PARAM_MAX_RECV_DLENGTH:
694 		case ISCSI_PARAM_MAX_XMIT_DLENGTH:
695 		case ISCSI_PARAM_HDRDGST_EN:
696 		case ISCSI_PARAM_DATADGST_EN:
697 		case ISCSI_PARAM_CONN_ADDRESS:
698 		case ISCSI_PARAM_CONN_PORT:
699 		case ISCSI_PARAM_EXP_STATSN:
700 		case ISCSI_PARAM_PERSISTENT_ADDRESS:
701 		case ISCSI_PARAM_PERSISTENT_PORT:
702 		case ISCSI_PARAM_PING_TMO:
703 		case ISCSI_PARAM_RECV_TMO:
704 		case ISCSI_PARAM_INITIAL_R2T_EN:
705 		case ISCSI_PARAM_MAX_R2T:
706 		case ISCSI_PARAM_IMM_DATA_EN:
707 		case ISCSI_PARAM_FIRST_BURST:
708 		case ISCSI_PARAM_MAX_BURST:
709 		case ISCSI_PARAM_PDU_INORDER_EN:
710 		case ISCSI_PARAM_DATASEQ_INORDER_EN:
711 		case ISCSI_PARAM_TARGET_NAME:
712 		case ISCSI_PARAM_TPGT:
713 		case ISCSI_PARAM_USERNAME:
714 		case ISCSI_PARAM_PASSWORD:
715 		case ISCSI_PARAM_USERNAME_IN:
716 		case ISCSI_PARAM_PASSWORD_IN:
717 		case ISCSI_PARAM_FAST_ABORT:
718 		case ISCSI_PARAM_ABORT_TMO:
719 		case ISCSI_PARAM_LU_RESET_TMO:
720 		case ISCSI_PARAM_TGT_RESET_TMO:
721 		case ISCSI_PARAM_IFACE_NAME:
722 		case ISCSI_PARAM_INITIATOR_NAME:
723 		case ISCSI_PARAM_DISCOVERY_SESS:
724 			return S_IRUGO;
725 		default:
726 			return 0;
727 		}
728 	}
729 
730 	return 0;
731 }
732 
733 static struct scsi_host_template iscsi_iser_sht = {
734 	.module                 = THIS_MODULE,
735 	.name                   = "iSCSI Initiator over iSER",
736 	.queuecommand           = iscsi_queuecommand,
737 	.change_queue_depth	= iscsi_change_queue_depth,
738 	.sg_tablesize           = ISCSI_ISER_SG_TABLESIZE,
739 	.max_sectors		= 1024,
740 	.cmd_per_lun            = ISER_DEF_CMD_PER_LUN,
741 	.eh_abort_handler       = iscsi_eh_abort,
742 	.eh_device_reset_handler= iscsi_eh_device_reset,
743 	.eh_target_reset_handler = iscsi_eh_recover_target,
744 	.target_alloc		= iscsi_target_alloc,
745 	.use_clustering         = DISABLE_CLUSTERING,
746 	.proc_name              = "iscsi_iser",
747 	.this_id                = -1,
748 };
749 
750 static struct iscsi_transport iscsi_iser_transport = {
751 	.owner                  = THIS_MODULE,
752 	.name                   = "iser",
753 	.caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_TEXT_NEGO,
754 	/* session management */
755 	.create_session         = iscsi_iser_session_create,
756 	.destroy_session        = iscsi_iser_session_destroy,
757 	/* connection management */
758 	.create_conn            = iscsi_iser_conn_create,
759 	.bind_conn              = iscsi_iser_conn_bind,
760 	.destroy_conn           = iscsi_conn_teardown,
761 	.attr_is_visible	= iser_attr_is_visible,
762 	.set_param              = iscsi_iser_set_param,
763 	.get_conn_param		= iscsi_conn_get_param,
764 	.get_ep_param		= iscsi_iser_get_ep_param,
765 	.get_session_param	= iscsi_session_get_param,
766 	.start_conn             = iscsi_iser_conn_start,
767 	.stop_conn              = iscsi_iser_conn_stop,
768 	/* iscsi host params */
769 	.get_host_param		= iscsi_host_get_param,
770 	.set_host_param		= iscsi_host_set_param,
771 	/* IO */
772 	.send_pdu		= iscsi_conn_send_pdu,
773 	.get_stats		= iscsi_iser_conn_get_stats,
774 	.init_task		= iscsi_iser_task_init,
775 	.xmit_task		= iscsi_iser_task_xmit,
776 	.cleanup_task		= iscsi_iser_cleanup_task,
777 	.alloc_pdu		= iscsi_iser_pdu_alloc,
778 	.check_protection	= iscsi_iser_check_protection,
779 	/* recovery */
780 	.session_recovery_timedout = iscsi_session_recovery_timedout,
781 
782 	.ep_connect             = iscsi_iser_ep_connect,
783 	.ep_poll                = iscsi_iser_ep_poll,
784 	.ep_disconnect          = iscsi_iser_ep_disconnect
785 };
786 
787 static int __init iser_init(void)
788 {
789 	int err;
790 
791 	iser_dbg("Starting iSER datamover...\n");
792 
793 	if (iscsi_max_lun < 1) {
794 		iser_err("Invalid max_lun value of %u\n", iscsi_max_lun);
795 		return -EINVAL;
796 	}
797 
798 	memset(&ig, 0, sizeof(struct iser_global));
799 
800 	ig.desc_cache = kmem_cache_create("iser_descriptors",
801 					  sizeof(struct iser_tx_desc),
802 					  0, SLAB_HWCACHE_ALIGN,
803 					  NULL);
804 	if (ig.desc_cache == NULL)
805 		return -ENOMEM;
806 
807 	/* device init is called only after the first addr resolution */
808 	mutex_init(&ig.device_list_mutex);
809 	INIT_LIST_HEAD(&ig.device_list);
810 	mutex_init(&ig.connlist_mutex);
811 	INIT_LIST_HEAD(&ig.connlist);
812 
813 	release_wq = alloc_workqueue("release workqueue", 0, 0);
814 	if (!release_wq) {
815 		iser_err("failed to allocate release workqueue\n");
816 		return -ENOMEM;
817 	}
818 
819 	iscsi_iser_scsi_transport = iscsi_register_transport(
820 							&iscsi_iser_transport);
821 	if (!iscsi_iser_scsi_transport) {
822 		iser_err("iscsi_register_transport failed\n");
823 		err = -EINVAL;
824 		goto register_transport_failure;
825 	}
826 
827 	return 0;
828 
829 register_transport_failure:
830 	kmem_cache_destroy(ig.desc_cache);
831 
832 	return err;
833 }
834 
835 static void __exit iser_exit(void)
836 {
837 	struct iser_conn *ib_conn, *n;
838 	int connlist_empty;
839 
840 	iser_dbg("Removing iSER datamover...\n");
841 	destroy_workqueue(release_wq);
842 
843 	mutex_lock(&ig.connlist_mutex);
844 	connlist_empty = list_empty(&ig.connlist);
845 	mutex_unlock(&ig.connlist_mutex);
846 
847 	if (!connlist_empty) {
848 		iser_err("Error cleanup stage completed but we still have iser "
849 			 "connections, destroying them anyway.\n");
850 		list_for_each_entry_safe(ib_conn, n, &ig.connlist, conn_list) {
851 			iser_conn_release(ib_conn);
852 		}
853 	}
854 
855 	iscsi_unregister_transport(&iscsi_iser_transport);
856 	kmem_cache_destroy(ig.desc_cache);
857 }
858 
859 module_init(iser_init);
860 module_exit(iser_exit);
861