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 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 
86 MODULE_DESCRIPTION("iSER (iSCSI Extensions for RDMA) Datamover");
87 MODULE_LICENSE("Dual BSD/GPL");
88 MODULE_AUTHOR("Alex Nezhinsky, Dan Bar Dov, Or Gerlitz");
89 MODULE_VERSION(DRV_VER);
90 
91 module_param_named(debug_level, iser_debug_level, int, 0644);
92 MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:disabled)");
93 
94 struct iser_global ig;
95 
96 void
97 iscsi_iser_recv(struct iscsi_conn *conn,
98 		struct iscsi_hdr *hdr, char *rx_data, int rx_data_len)
99 {
100 	int rc = 0;
101 	int datalen;
102 	int ahslen;
103 
104 	/* verify PDU length */
105 	datalen = ntoh24(hdr->dlength);
106 	if (datalen > rx_data_len || (datalen + 4) < rx_data_len) {
107 		iser_err("wrong datalen %d (hdr), %d (IB)\n",
108 			datalen, rx_data_len);
109 		rc = ISCSI_ERR_DATALEN;
110 		goto error;
111 	}
112 
113 	if (datalen != rx_data_len)
114 		iser_dbg("aligned datalen (%d) hdr, %d (IB)\n",
115 			datalen, rx_data_len);
116 
117 	/* read AHS */
118 	ahslen = hdr->hlength * 4;
119 
120 	rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
121 	if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
122 		goto error;
123 
124 	return;
125 error:
126 	iscsi_conn_failure(conn, rc);
127 }
128 
129 static int iscsi_iser_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
130 {
131 	struct iscsi_iser_task *iser_task = task->dd_data;
132 
133 	task->hdr = (struct iscsi_hdr *)&iser_task->desc.iscsi_header;
134 	task->hdr_max = sizeof(iser_task->desc.iscsi_header);
135 	return 0;
136 }
137 
138 int iser_initialize_task_headers(struct iscsi_task *task,
139 						struct iser_tx_desc *tx_desc)
140 {
141 	struct iscsi_iser_conn *iser_conn = task->conn->dd_data;
142 	struct iser_device     *device    = iser_conn->ib_conn->device;
143 	struct iscsi_iser_task *iser_task = task->dd_data;
144 	u64 dma_addr;
145 
146 	dma_addr = ib_dma_map_single(device->ib_device, (void *)tx_desc,
147 				ISER_HEADERS_LEN, DMA_TO_DEVICE);
148 	if (ib_dma_mapping_error(device->ib_device, dma_addr))
149 		return -ENOMEM;
150 
151 	tx_desc->dma_addr = dma_addr;
152 	tx_desc->tx_sg[0].addr   = tx_desc->dma_addr;
153 	tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;
154 	tx_desc->tx_sg[0].lkey   = device->mr->lkey;
155 
156 	iser_task->iser_conn		= iser_conn;
157 	return 0;
158 }
159 /**
160  * iscsi_iser_task_init - Initialize task
161  * @task: iscsi task
162  *
163  * Initialize the task for the scsi command or mgmt command.
164  */
165 static int
166 iscsi_iser_task_init(struct iscsi_task *task)
167 {
168 	struct iscsi_iser_task *iser_task = task->dd_data;
169 
170 	if (iser_initialize_task_headers(task, &iser_task->desc))
171 			return -ENOMEM;
172 
173 	/* mgmt task */
174 	if (!task->sc)
175 		return 0;
176 
177 	iser_task->command_sent = 0;
178 	iser_task_rdma_init(iser_task);
179 	return 0;
180 }
181 
182 /**
183  * iscsi_iser_mtask_xmit - xmit management(immediate) task
184  * @conn: iscsi connection
185  * @task: task management task
186  *
187  * Notes:
188  *	The function can return -EAGAIN in which case caller must
189  *	call it again later, or recover. '0' return code means successful
190  *	xmit.
191  *
192  **/
193 static int
194 iscsi_iser_mtask_xmit(struct iscsi_conn *conn, struct iscsi_task *task)
195 {
196 	int error = 0;
197 
198 	iser_dbg("mtask xmit [cid %d itt 0x%x]\n", conn->id, task->itt);
199 
200 	error = iser_send_control(conn, task);
201 
202 	/* since iser xmits control with zero copy, tasks can not be recycled
203 	 * right after sending them.
204 	 * The recycling scheme is based on whether a response is expected
205 	 * - if yes, the task is recycled at iscsi_complete_pdu
206 	 * - if no,  the task is recycled at iser_snd_completion
207 	 */
208 	return error;
209 }
210 
211 static int
212 iscsi_iser_task_xmit_unsol_data(struct iscsi_conn *conn,
213 				 struct iscsi_task *task)
214 {
215 	struct iscsi_r2t_info *r2t = &task->unsol_r2t;
216 	struct iscsi_data hdr;
217 	int error = 0;
218 
219 	/* Send data-out PDUs while there's still unsolicited data to send */
220 	while (iscsi_task_has_unsol_data(task)) {
221 		iscsi_prep_data_out_pdu(task, r2t, &hdr);
222 		iser_dbg("Sending data-out: itt 0x%x, data count %d\n",
223 			   hdr.itt, r2t->data_count);
224 
225 		/* the buffer description has been passed with the command */
226 		/* Send the command */
227 		error = iser_send_data_out(conn, task, &hdr);
228 		if (error) {
229 			r2t->datasn--;
230 			goto iscsi_iser_task_xmit_unsol_data_exit;
231 		}
232 		r2t->sent += r2t->data_count;
233 		iser_dbg("Need to send %d more as data-out PDUs\n",
234 			   r2t->data_length - r2t->sent);
235 	}
236 
237 iscsi_iser_task_xmit_unsol_data_exit:
238 	return error;
239 }
240 
241 static int
242 iscsi_iser_task_xmit(struct iscsi_task *task)
243 {
244 	struct iscsi_conn *conn = task->conn;
245 	struct iscsi_iser_task *iser_task = task->dd_data;
246 	int error = 0;
247 
248 	if (!task->sc)
249 		return iscsi_iser_mtask_xmit(conn, task);
250 
251 	if (task->sc->sc_data_direction == DMA_TO_DEVICE) {
252 		BUG_ON(scsi_bufflen(task->sc) == 0);
253 
254 		iser_dbg("cmd [itt %x total %d imm %d unsol_data %d\n",
255 			   task->itt, scsi_bufflen(task->sc),
256 			   task->imm_count, task->unsol_r2t.data_length);
257 	}
258 
259 	iser_dbg("ctask xmit [cid %d itt 0x%x]\n",
260 		   conn->id, task->itt);
261 
262 	/* Send the cmd PDU */
263 	if (!iser_task->command_sent) {
264 		error = iser_send_command(conn, task);
265 		if (error)
266 			goto iscsi_iser_task_xmit_exit;
267 		iser_task->command_sent = 1;
268 	}
269 
270 	/* Send unsolicited data-out PDU(s) if necessary */
271 	if (iscsi_task_has_unsol_data(task))
272 		error = iscsi_iser_task_xmit_unsol_data(conn, task);
273 
274  iscsi_iser_task_xmit_exit:
275 	return error;
276 }
277 
278 static void iscsi_iser_cleanup_task(struct iscsi_task *task)
279 {
280 	struct iscsi_iser_task *iser_task = task->dd_data;
281 	struct iser_tx_desc	*tx_desc = &iser_task->desc;
282 
283 	struct iscsi_iser_conn *iser_conn = task->conn->dd_data;
284 	struct iser_device     *device    = iser_conn->ib_conn->device;
285 
286 	ib_dma_unmap_single(device->ib_device,
287 		tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
288 
289 	/* mgmt tasks do not need special cleanup */
290 	if (!task->sc)
291 		return;
292 
293 	if (iser_task->status == ISER_TASK_STATUS_STARTED) {
294 		iser_task->status = ISER_TASK_STATUS_COMPLETED;
295 		iser_task_rdma_finalize(iser_task);
296 	}
297 }
298 
299 static struct iscsi_cls_conn *
300 iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
301 {
302 	struct iscsi_conn *conn;
303 	struct iscsi_cls_conn *cls_conn;
304 	struct iscsi_iser_conn *iser_conn;
305 
306 	cls_conn = iscsi_conn_setup(cls_session, sizeof(*iser_conn), conn_idx);
307 	if (!cls_conn)
308 		return NULL;
309 	conn = cls_conn->dd_data;
310 
311 	/*
312 	 * due to issues with the login code re iser sematics
313 	 * this not set in iscsi_conn_setup - FIXME
314 	 */
315 	conn->max_recv_dlength = ISER_RECV_DATA_SEG_LEN;
316 
317 	iser_conn = conn->dd_data;
318 	conn->dd_data = iser_conn;
319 	iser_conn->iscsi_conn = conn;
320 
321 	return cls_conn;
322 }
323 
324 static void
325 iscsi_iser_conn_destroy(struct iscsi_cls_conn *cls_conn)
326 {
327 	struct iscsi_conn *conn = cls_conn->dd_data;
328 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
329 	struct iser_conn *ib_conn = iser_conn->ib_conn;
330 
331 	iscsi_conn_teardown(cls_conn);
332 	/*
333 	 * Userspace will normally call the stop callback and
334 	 * already have freed the ib_conn, but if it goofed up then
335 	 * we free it here.
336 	 */
337 	if (ib_conn) {
338 		ib_conn->iser_conn = NULL;
339 		iser_conn_put(ib_conn, 1); /* deref iscsi/ib conn unbinding */
340 	}
341 }
342 
343 static int
344 iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
345 		     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
346 		     int is_leading)
347 {
348 	struct iscsi_conn *conn = cls_conn->dd_data;
349 	struct iscsi_iser_conn *iser_conn;
350 	struct iser_conn *ib_conn;
351 	struct iscsi_endpoint *ep;
352 	int error;
353 
354 	error = iscsi_conn_bind(cls_session, cls_conn, is_leading);
355 	if (error)
356 		return error;
357 
358 	/* the transport ep handle comes from user space so it must be
359 	 * verified against the global ib connections list */
360 	ep = iscsi_lookup_endpoint(transport_eph);
361 	if (!ep) {
362 		iser_err("can't bind eph %llx\n",
363 			 (unsigned long long)transport_eph);
364 		return -EINVAL;
365 	}
366 	ib_conn = ep->dd_data;
367 
368 	if (iser_alloc_rx_descriptors(ib_conn))
369 		return -ENOMEM;
370 
371 	/* binds the iSER connection retrieved from the previously
372 	 * connected ep_handle to the iSCSI layer connection. exchanges
373 	 * connection pointers */
374 	iser_info("binding iscsi/iser conn %p %p to ib_conn %p\n",
375 		  conn, conn->dd_data, ib_conn);
376 	iser_conn = conn->dd_data;
377 	ib_conn->iser_conn = iser_conn;
378 	iser_conn->ib_conn  = ib_conn;
379 	iser_conn_get(ib_conn); /* ref iscsi/ib conn binding */
380 	return 0;
381 }
382 
383 static void
384 iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
385 {
386 	struct iscsi_conn *conn = cls_conn->dd_data;
387 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
388 	struct iser_conn *ib_conn = iser_conn->ib_conn;
389 
390 	/*
391 	 * Userspace may have goofed up and not bound the connection or
392 	 * might have only partially setup the connection.
393 	 */
394 	if (ib_conn) {
395 		iscsi_conn_stop(cls_conn, flag);
396 		/*
397 		 * There is no unbind event so the stop callback
398 		 * must release the ref from the bind.
399 		 */
400 		iser_conn_put(ib_conn, 1); /* deref iscsi/ib conn unbinding */
401 	}
402 	iser_conn->ib_conn = NULL;
403 }
404 
405 static void iscsi_iser_session_destroy(struct iscsi_cls_session *cls_session)
406 {
407 	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
408 
409 	iscsi_session_teardown(cls_session);
410 	iscsi_host_remove(shost);
411 	iscsi_host_free(shost);
412 }
413 
414 static struct iscsi_cls_session *
415 iscsi_iser_session_create(struct iscsi_endpoint *ep,
416 			  uint16_t cmds_max, uint16_t qdepth,
417 			  uint32_t initial_cmdsn)
418 {
419 	struct iscsi_cls_session *cls_session;
420 	struct iscsi_session *session;
421 	struct Scsi_Host *shost;
422 	struct iser_conn *ib_conn;
423 
424 	shost = iscsi_host_alloc(&iscsi_iser_sht, 0, 0);
425 	if (!shost)
426 		return NULL;
427 	shost->transportt = iscsi_iser_scsi_transport;
428 	shost->max_lun = iscsi_max_lun;
429 	shost->max_id = 0;
430 	shost->max_channel = 0;
431 	shost->max_cmd_len = 16;
432 
433 	/*
434 	 * older userspace tools (before 2.0-870) did not pass us
435 	 * the leading conn's ep so this will be NULL;
436 	 */
437 	if (ep)
438 		ib_conn = ep->dd_data;
439 
440 	if (iscsi_host_add(shost,
441 			   ep ? ib_conn->device->ib_device->dma_device : NULL))
442 		goto free_host;
443 
444 	/*
445 	 * we do not support setting can_queue cmd_per_lun from userspace yet
446 	 * because we preallocate so many resources
447 	 */
448 	cls_session = iscsi_session_setup(&iscsi_iser_transport, shost,
449 					  ISCSI_DEF_XMIT_CMDS_MAX, 0,
450 					  sizeof(struct iscsi_iser_task),
451 					  initial_cmdsn, 0);
452 	if (!cls_session)
453 		goto remove_host;
454 	session = cls_session->dd_data;
455 
456 	shost->can_queue = session->scsi_cmds_max;
457 	return cls_session;
458 
459 remove_host:
460 	iscsi_host_remove(shost);
461 free_host:
462 	iscsi_host_free(shost);
463 	return NULL;
464 }
465 
466 static int
467 iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,
468 		     enum iscsi_param param, char *buf, int buflen)
469 {
470 	int value;
471 
472 	switch (param) {
473 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
474 		/* TBD */
475 		break;
476 	case ISCSI_PARAM_HDRDGST_EN:
477 		sscanf(buf, "%d", &value);
478 		if (value) {
479 			iser_err("DataDigest wasn't negotiated to None");
480 			return -EPROTO;
481 		}
482 		break;
483 	case ISCSI_PARAM_DATADGST_EN:
484 		sscanf(buf, "%d", &value);
485 		if (value) {
486 			iser_err("DataDigest wasn't negotiated to None");
487 			return -EPROTO;
488 		}
489 		break;
490 	case ISCSI_PARAM_IFMARKER_EN:
491 		sscanf(buf, "%d", &value);
492 		if (value) {
493 			iser_err("IFMarker wasn't negotiated to No");
494 			return -EPROTO;
495 		}
496 		break;
497 	case ISCSI_PARAM_OFMARKER_EN:
498 		sscanf(buf, "%d", &value);
499 		if (value) {
500 			iser_err("OFMarker wasn't negotiated to No");
501 			return -EPROTO;
502 		}
503 		break;
504 	default:
505 		return iscsi_set_param(cls_conn, param, buf, buflen);
506 	}
507 
508 	return 0;
509 }
510 
511 static void
512 iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
513 {
514 	struct iscsi_conn *conn = cls_conn->dd_data;
515 
516 	stats->txdata_octets = conn->txdata_octets;
517 	stats->rxdata_octets = conn->rxdata_octets;
518 	stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
519 	stats->dataout_pdus = conn->dataout_pdus_cnt;
520 	stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
521 	stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */
522 	stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
523 	stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
524 	stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
525 	stats->custom_length = 4;
526 	strcpy(stats->custom[0].desc, "qp_tx_queue_full");
527 	stats->custom[0].value = 0; /* TB iser_conn->qp_tx_queue_full; */
528 	strcpy(stats->custom[1].desc, "fmr_map_not_avail");
529 	stats->custom[1].value = 0; /* TB iser_conn->fmr_map_not_avail */;
530 	strcpy(stats->custom[2].desc, "eh_abort_cnt");
531 	stats->custom[2].value = conn->eh_abort_cnt;
532 	strcpy(stats->custom[3].desc, "fmr_unalign_cnt");
533 	stats->custom[3].value = conn->fmr_unalign_cnt;
534 }
535 
536 static int iscsi_iser_get_ep_param(struct iscsi_endpoint *ep,
537 				   enum iscsi_param param, char *buf)
538 {
539 	struct iser_conn *ib_conn = ep->dd_data;
540 	int len;
541 
542 	switch (param) {
543 	case ISCSI_PARAM_CONN_PORT:
544 	case ISCSI_PARAM_CONN_ADDRESS:
545 		if (!ib_conn || !ib_conn->cma_id)
546 			return -ENOTCONN;
547 
548 		return iscsi_conn_get_addr_param((struct sockaddr_storage *)
549 					&ib_conn->cma_id->route.addr.dst_addr,
550 					param, buf);
551 		break;
552 	default:
553 		return -ENOSYS;
554 	}
555 
556 	return len;
557 }
558 
559 static struct iscsi_endpoint *
560 iscsi_iser_ep_connect(struct Scsi_Host *shost, struct sockaddr *dst_addr,
561 		      int non_blocking)
562 {
563 	int err;
564 	struct iser_conn *ib_conn;
565 	struct iscsi_endpoint *ep;
566 
567 	ep = iscsi_create_endpoint(sizeof(*ib_conn));
568 	if (!ep)
569 		return ERR_PTR(-ENOMEM);
570 
571 	ib_conn = ep->dd_data;
572 	ib_conn->ep = ep;
573 	iser_conn_init(ib_conn);
574 
575 	err = iser_connect(ib_conn, NULL, (struct sockaddr_in *)dst_addr,
576 			   non_blocking);
577 	if (err)
578 		return ERR_PTR(err);
579 
580 	return ep;
581 }
582 
583 static int
584 iscsi_iser_ep_poll(struct iscsi_endpoint *ep, int timeout_ms)
585 {
586 	struct iser_conn *ib_conn;
587 	int rc;
588 
589 	ib_conn = ep->dd_data;
590 	rc = wait_event_interruptible_timeout(ib_conn->wait,
591 			     ib_conn->state == ISER_CONN_UP,
592 			     msecs_to_jiffies(timeout_ms));
593 
594 	/* if conn establishment failed, return error code to iscsi */
595 	if (!rc &&
596 	    (ib_conn->state == ISER_CONN_TERMINATING ||
597 	     ib_conn->state == ISER_CONN_DOWN))
598 		rc = -1;
599 
600 	iser_info("ib conn %p rc = %d\n", ib_conn, rc);
601 
602 	if (rc > 0)
603 		return 1; /* success, this is the equivalent of POLLOUT */
604 	else if (!rc)
605 		return 0; /* timeout */
606 	else
607 		return rc; /* signal */
608 }
609 
610 static void
611 iscsi_iser_ep_disconnect(struct iscsi_endpoint *ep)
612 {
613 	struct iser_conn *ib_conn;
614 
615 	ib_conn = ep->dd_data;
616 	if (ib_conn->iser_conn)
617 		/*
618 		 * Must suspend xmit path if the ep is bound to the
619 		 * iscsi_conn, so we know we are not accessing the ib_conn
620 		 * when we free it.
621 		 *
622 		 * This may not be bound if the ep poll failed.
623 		 */
624 		iscsi_suspend_tx(ib_conn->iser_conn->iscsi_conn);
625 
626 
627 	iser_info("ib conn %p state %d\n", ib_conn, ib_conn->state);
628 	iser_conn_terminate(ib_conn);
629 }
630 
631 static umode_t iser_attr_is_visible(int param_type, int param)
632 {
633 	switch (param_type) {
634 	case ISCSI_HOST_PARAM:
635 		switch (param) {
636 		case ISCSI_HOST_PARAM_NETDEV_NAME:
637 		case ISCSI_HOST_PARAM_HWADDRESS:
638 		case ISCSI_HOST_PARAM_INITIATOR_NAME:
639 			return S_IRUGO;
640 		default:
641 			return 0;
642 		}
643 	case ISCSI_PARAM:
644 		switch (param) {
645 		case ISCSI_PARAM_MAX_RECV_DLENGTH:
646 		case ISCSI_PARAM_MAX_XMIT_DLENGTH:
647 		case ISCSI_PARAM_HDRDGST_EN:
648 		case ISCSI_PARAM_DATADGST_EN:
649 		case ISCSI_PARAM_CONN_ADDRESS:
650 		case ISCSI_PARAM_CONN_PORT:
651 		case ISCSI_PARAM_EXP_STATSN:
652 		case ISCSI_PARAM_PERSISTENT_ADDRESS:
653 		case ISCSI_PARAM_PERSISTENT_PORT:
654 		case ISCSI_PARAM_PING_TMO:
655 		case ISCSI_PARAM_RECV_TMO:
656 		case ISCSI_PARAM_INITIAL_R2T_EN:
657 		case ISCSI_PARAM_MAX_R2T:
658 		case ISCSI_PARAM_IMM_DATA_EN:
659 		case ISCSI_PARAM_FIRST_BURST:
660 		case ISCSI_PARAM_MAX_BURST:
661 		case ISCSI_PARAM_PDU_INORDER_EN:
662 		case ISCSI_PARAM_DATASEQ_INORDER_EN:
663 		case ISCSI_PARAM_TARGET_NAME:
664 		case ISCSI_PARAM_TPGT:
665 		case ISCSI_PARAM_USERNAME:
666 		case ISCSI_PARAM_PASSWORD:
667 		case ISCSI_PARAM_USERNAME_IN:
668 		case ISCSI_PARAM_PASSWORD_IN:
669 		case ISCSI_PARAM_FAST_ABORT:
670 		case ISCSI_PARAM_ABORT_TMO:
671 		case ISCSI_PARAM_LU_RESET_TMO:
672 		case ISCSI_PARAM_TGT_RESET_TMO:
673 		case ISCSI_PARAM_IFACE_NAME:
674 		case ISCSI_PARAM_INITIATOR_NAME:
675 			return S_IRUGO;
676 		default:
677 			return 0;
678 		}
679 	}
680 
681 	return 0;
682 }
683 
684 static struct scsi_host_template iscsi_iser_sht = {
685 	.module                 = THIS_MODULE,
686 	.name                   = "iSCSI Initiator over iSER",
687 	.queuecommand           = iscsi_queuecommand,
688 	.change_queue_depth	= iscsi_change_queue_depth,
689 	.sg_tablesize           = ISCSI_ISER_SG_TABLESIZE,
690 	.max_sectors		= 1024,
691 	.cmd_per_lun            = ISER_DEF_CMD_PER_LUN,
692 	.eh_abort_handler       = iscsi_eh_abort,
693 	.eh_device_reset_handler= iscsi_eh_device_reset,
694 	.eh_target_reset_handler = iscsi_eh_recover_target,
695 	.target_alloc		= iscsi_target_alloc,
696 	.use_clustering         = DISABLE_CLUSTERING,
697 	.proc_name              = "iscsi_iser",
698 	.this_id                = -1,
699 };
700 
701 static struct iscsi_transport iscsi_iser_transport = {
702 	.owner                  = THIS_MODULE,
703 	.name                   = "iser",
704 	.caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T,
705 	/* session management */
706 	.create_session         = iscsi_iser_session_create,
707 	.destroy_session        = iscsi_iser_session_destroy,
708 	/* connection management */
709 	.create_conn            = iscsi_iser_conn_create,
710 	.bind_conn              = iscsi_iser_conn_bind,
711 	.destroy_conn           = iscsi_iser_conn_destroy,
712 	.attr_is_visible	= iser_attr_is_visible,
713 	.set_param              = iscsi_iser_set_param,
714 	.get_conn_param		= iscsi_conn_get_param,
715 	.get_ep_param		= iscsi_iser_get_ep_param,
716 	.get_session_param	= iscsi_session_get_param,
717 	.start_conn             = iscsi_conn_start,
718 	.stop_conn              = iscsi_iser_conn_stop,
719 	/* iscsi host params */
720 	.get_host_param		= iscsi_host_get_param,
721 	.set_host_param		= iscsi_host_set_param,
722 	/* IO */
723 	.send_pdu		= iscsi_conn_send_pdu,
724 	.get_stats		= iscsi_iser_conn_get_stats,
725 	.init_task		= iscsi_iser_task_init,
726 	.xmit_task		= iscsi_iser_task_xmit,
727 	.cleanup_task		= iscsi_iser_cleanup_task,
728 	.alloc_pdu		= iscsi_iser_pdu_alloc,
729 	/* recovery */
730 	.session_recovery_timedout = iscsi_session_recovery_timedout,
731 
732 	.ep_connect             = iscsi_iser_ep_connect,
733 	.ep_poll                = iscsi_iser_ep_poll,
734 	.ep_disconnect          = iscsi_iser_ep_disconnect
735 };
736 
737 static int __init iser_init(void)
738 {
739 	int err;
740 
741 	iser_dbg("Starting iSER datamover...\n");
742 
743 	if (iscsi_max_lun < 1) {
744 		iser_err("Invalid max_lun value of %u\n", iscsi_max_lun);
745 		return -EINVAL;
746 	}
747 
748 	memset(&ig, 0, sizeof(struct iser_global));
749 
750 	ig.desc_cache = kmem_cache_create("iser_descriptors",
751 					  sizeof(struct iser_tx_desc),
752 					  0, SLAB_HWCACHE_ALIGN,
753 					  NULL);
754 	if (ig.desc_cache == NULL)
755 		return -ENOMEM;
756 
757 	/* device init is called only after the first addr resolution */
758 	mutex_init(&ig.device_list_mutex);
759 	INIT_LIST_HEAD(&ig.device_list);
760 	mutex_init(&ig.connlist_mutex);
761 	INIT_LIST_HEAD(&ig.connlist);
762 
763 	iscsi_iser_scsi_transport = iscsi_register_transport(
764 							&iscsi_iser_transport);
765 	if (!iscsi_iser_scsi_transport) {
766 		iser_err("iscsi_register_transport failed\n");
767 		err = -EINVAL;
768 		goto register_transport_failure;
769 	}
770 
771 	return 0;
772 
773 register_transport_failure:
774 	kmem_cache_destroy(ig.desc_cache);
775 
776 	return err;
777 }
778 
779 static void __exit iser_exit(void)
780 {
781 	iser_dbg("Removing iSER datamover...\n");
782 	iscsi_unregister_transport(&iscsi_iser_transport);
783 	kmem_cache_destroy(ig.desc_cache);
784 }
785 
786 module_init(iser_init);
787 module_exit(iser_exit);
788