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 struct iser_global ig;
103 
104 void
105 iscsi_iser_recv(struct iscsi_conn *conn,
106 		struct iscsi_hdr *hdr, char *rx_data, int rx_data_len)
107 {
108 	int rc = 0;
109 	int datalen;
110 	int ahslen;
111 
112 	/* verify PDU length */
113 	datalen = ntoh24(hdr->dlength);
114 	if (datalen > rx_data_len || (datalen + 4) < rx_data_len) {
115 		iser_err("wrong datalen %d (hdr), %d (IB)\n",
116 			datalen, rx_data_len);
117 		rc = ISCSI_ERR_DATALEN;
118 		goto error;
119 	}
120 
121 	if (datalen != rx_data_len)
122 		iser_dbg("aligned datalen (%d) hdr, %d (IB)\n",
123 			datalen, rx_data_len);
124 
125 	/* read AHS */
126 	ahslen = hdr->hlength * 4;
127 
128 	rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
129 	if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
130 		goto error;
131 
132 	return;
133 error:
134 	iscsi_conn_failure(conn, rc);
135 }
136 
137 static int iscsi_iser_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
138 {
139 	struct iscsi_iser_task *iser_task = task->dd_data;
140 
141 	task->hdr = (struct iscsi_hdr *)&iser_task->desc.iscsi_header;
142 	task->hdr_max = sizeof(iser_task->desc.iscsi_header);
143 	return 0;
144 }
145 
146 int iser_initialize_task_headers(struct iscsi_task *task,
147 						struct iser_tx_desc *tx_desc)
148 {
149 	struct iser_conn       *ib_conn   = task->conn->dd_data;
150 	struct iser_device     *device    = ib_conn->device;
151 	struct iscsi_iser_task *iser_task = task->dd_data;
152 	u64 dma_addr;
153 
154 	dma_addr = ib_dma_map_single(device->ib_device, (void *)tx_desc,
155 				ISER_HEADERS_LEN, DMA_TO_DEVICE);
156 	if (ib_dma_mapping_error(device->ib_device, dma_addr))
157 		return -ENOMEM;
158 
159 	tx_desc->dma_addr = dma_addr;
160 	tx_desc->tx_sg[0].addr   = tx_desc->dma_addr;
161 	tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;
162 	tx_desc->tx_sg[0].lkey   = device->mr->lkey;
163 
164 	iser_task->ib_conn = ib_conn;
165 	return 0;
166 }
167 /**
168  * iscsi_iser_task_init - Initialize task
169  * @task: iscsi task
170  *
171  * Initialize the task for the scsi command or mgmt command.
172  */
173 static int
174 iscsi_iser_task_init(struct iscsi_task *task)
175 {
176 	struct iscsi_iser_task *iser_task = task->dd_data;
177 
178 	if (iser_initialize_task_headers(task, &iser_task->desc))
179 			return -ENOMEM;
180 
181 	/* mgmt task */
182 	if (!task->sc)
183 		return 0;
184 
185 	iser_task->command_sent = 0;
186 	iser_task_rdma_init(iser_task);
187 	iser_task->sc = task->sc;
188 
189 	return 0;
190 }
191 
192 /**
193  * iscsi_iser_mtask_xmit - xmit management(immediate) task
194  * @conn: iscsi connection
195  * @task: task management task
196  *
197  * Notes:
198  *	The function can return -EAGAIN in which case caller must
199  *	call it again later, or recover. '0' return code means successful
200  *	xmit.
201  *
202  **/
203 static int
204 iscsi_iser_mtask_xmit(struct iscsi_conn *conn, struct iscsi_task *task)
205 {
206 	int error = 0;
207 
208 	iser_dbg("mtask xmit [cid %d itt 0x%x]\n", conn->id, task->itt);
209 
210 	error = iser_send_control(conn, task);
211 
212 	/* since iser xmits control with zero copy, tasks can not be recycled
213 	 * right after sending them.
214 	 * The recycling scheme is based on whether a response is expected
215 	 * - if yes, the task is recycled at iscsi_complete_pdu
216 	 * - if no,  the task is recycled at iser_snd_completion
217 	 */
218 	return error;
219 }
220 
221 static int
222 iscsi_iser_task_xmit_unsol_data(struct iscsi_conn *conn,
223 				 struct iscsi_task *task)
224 {
225 	struct iscsi_r2t_info *r2t = &task->unsol_r2t;
226 	struct iscsi_data hdr;
227 	int error = 0;
228 
229 	/* Send data-out PDUs while there's still unsolicited data to send */
230 	while (iscsi_task_has_unsol_data(task)) {
231 		iscsi_prep_data_out_pdu(task, r2t, &hdr);
232 		iser_dbg("Sending data-out: itt 0x%x, data count %d\n",
233 			   hdr.itt, r2t->data_count);
234 
235 		/* the buffer description has been passed with the command */
236 		/* Send the command */
237 		error = iser_send_data_out(conn, task, &hdr);
238 		if (error) {
239 			r2t->datasn--;
240 			goto iscsi_iser_task_xmit_unsol_data_exit;
241 		}
242 		r2t->sent += r2t->data_count;
243 		iser_dbg("Need to send %d more as data-out PDUs\n",
244 			   r2t->data_length - r2t->sent);
245 	}
246 
247 iscsi_iser_task_xmit_unsol_data_exit:
248 	return error;
249 }
250 
251 static int
252 iscsi_iser_task_xmit(struct iscsi_task *task)
253 {
254 	struct iscsi_conn *conn = task->conn;
255 	struct iscsi_iser_task *iser_task = task->dd_data;
256 	int error = 0;
257 
258 	if (!task->sc)
259 		return iscsi_iser_mtask_xmit(conn, task);
260 
261 	if (task->sc->sc_data_direction == DMA_TO_DEVICE) {
262 		BUG_ON(scsi_bufflen(task->sc) == 0);
263 
264 		iser_dbg("cmd [itt %x total %d imm %d unsol_data %d\n",
265 			   task->itt, scsi_bufflen(task->sc),
266 			   task->imm_count, task->unsol_r2t.data_length);
267 	}
268 
269 	iser_dbg("ctask xmit [cid %d itt 0x%x]\n",
270 		   conn->id, task->itt);
271 
272 	/* Send the cmd PDU */
273 	if (!iser_task->command_sent) {
274 		error = iser_send_command(conn, task);
275 		if (error)
276 			goto iscsi_iser_task_xmit_exit;
277 		iser_task->command_sent = 1;
278 	}
279 
280 	/* Send unsolicited data-out PDU(s) if necessary */
281 	if (iscsi_task_has_unsol_data(task))
282 		error = iscsi_iser_task_xmit_unsol_data(conn, task);
283 
284  iscsi_iser_task_xmit_exit:
285 	return error;
286 }
287 
288 static void iscsi_iser_cleanup_task(struct iscsi_task *task)
289 {
290 	struct iscsi_iser_task *iser_task = task->dd_data;
291 	struct iser_tx_desc    *tx_desc   = &iser_task->desc;
292 	struct iser_conn       *ib_conn	  = task->conn->dd_data;
293 	struct iser_device     *device	  = ib_conn->device;
294 
295 	ib_dma_unmap_single(device->ib_device,
296 		tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
297 
298 	/* mgmt tasks do not need special cleanup */
299 	if (!task->sc)
300 		return;
301 
302 	if (iser_task->status == ISER_TASK_STATUS_STARTED) {
303 		iser_task->status = ISER_TASK_STATUS_COMPLETED;
304 		iser_task_rdma_finalize(iser_task);
305 	}
306 }
307 
308 static u8 iscsi_iser_check_protection(struct iscsi_task *task, sector_t *sector)
309 {
310 	struct iscsi_iser_task *iser_task = task->dd_data;
311 
312 	if (iser_task->dir[ISER_DIR_IN])
313 		return iser_check_task_pi_status(iser_task, ISER_DIR_IN,
314 						 sector);
315 	else
316 		return iser_check_task_pi_status(iser_task, ISER_DIR_OUT,
317 						 sector);
318 }
319 
320 static struct iscsi_cls_conn *
321 iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
322 {
323 	struct iscsi_conn *conn;
324 	struct iscsi_cls_conn *cls_conn;
325 
326 	cls_conn = iscsi_conn_setup(cls_session, 0, conn_idx);
327 	if (!cls_conn)
328 		return NULL;
329 	conn = cls_conn->dd_data;
330 
331 	/*
332 	 * due to issues with the login code re iser sematics
333 	 * this not set in iscsi_conn_setup - FIXME
334 	 */
335 	conn->max_recv_dlength = ISER_RECV_DATA_SEG_LEN;
336 
337 	return cls_conn;
338 }
339 
340 static void
341 iscsi_iser_conn_destroy(struct iscsi_cls_conn *cls_conn)
342 {
343 	struct iscsi_conn *conn = cls_conn->dd_data;
344 	struct iser_conn *ib_conn = conn->dd_data;
345 
346 	iscsi_conn_teardown(cls_conn);
347 	/*
348 	 * Userspace will normally call the stop callback and
349 	 * already have freed the ib_conn, but if it goofed up then
350 	 * we free it here.
351 	 */
352 	if (ib_conn) {
353 		ib_conn->iscsi_conn = NULL;
354 		iser_conn_put(ib_conn, 1); /* deref iscsi/ib conn unbinding */
355 	}
356 }
357 
358 static int
359 iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
360 		     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
361 		     int is_leading)
362 {
363 	struct iscsi_conn *conn = cls_conn->dd_data;
364 	struct iscsi_session *session;
365 	struct iser_conn *ib_conn;
366 	struct iscsi_endpoint *ep;
367 	int error;
368 
369 	error = iscsi_conn_bind(cls_session, cls_conn, is_leading);
370 	if (error)
371 		return error;
372 
373 	/* the transport ep handle comes from user space so it must be
374 	 * verified against the global ib connections list */
375 	ep = iscsi_lookup_endpoint(transport_eph);
376 	if (!ep) {
377 		iser_err("can't bind eph %llx\n",
378 			 (unsigned long long)transport_eph);
379 		return -EINVAL;
380 	}
381 	ib_conn = ep->dd_data;
382 
383 	session = conn->session;
384 	if (iser_alloc_rx_descriptors(ib_conn, session))
385 		return -ENOMEM;
386 
387 	/* binds the iSER connection retrieved from the previously
388 	 * connected ep_handle to the iSCSI layer connection. exchanges
389 	 * connection pointers */
390 	iser_info("binding iscsi conn %p to ib_conn %p\n", conn, ib_conn);
391 
392 	conn->dd_data = ib_conn;
393 	ib_conn->iscsi_conn = conn;
394 
395 	iser_conn_get(ib_conn); /* ref iscsi/ib conn binding */
396 	return 0;
397 }
398 
399 static void
400 iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
401 {
402 	struct iscsi_conn *conn = cls_conn->dd_data;
403 	struct iser_conn *ib_conn = conn->dd_data;
404 
405 	/*
406 	 * Userspace may have goofed up and not bound the connection or
407 	 * might have only partially setup the connection.
408 	 */
409 	if (ib_conn) {
410 		iscsi_conn_stop(cls_conn, flag);
411 		/*
412 		 * There is no unbind event so the stop callback
413 		 * must release the ref from the bind.
414 		 */
415 		iser_conn_put(ib_conn, 1); /* deref iscsi/ib conn unbinding */
416 	}
417 	conn->dd_data = NULL;
418 }
419 
420 static void iscsi_iser_session_destroy(struct iscsi_cls_session *cls_session)
421 {
422 	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
423 
424 	iscsi_session_teardown(cls_session);
425 	iscsi_host_remove(shost);
426 	iscsi_host_free(shost);
427 }
428 
429 static inline unsigned int
430 iser_dif_prot_caps(int prot_caps)
431 {
432 	return ((prot_caps & IB_PROT_T10DIF_TYPE_1) ? SHOST_DIF_TYPE1_PROTECTION |
433 						      SHOST_DIX_TYPE1_PROTECTION : 0) |
434 	       ((prot_caps & IB_PROT_T10DIF_TYPE_2) ? SHOST_DIF_TYPE2_PROTECTION |
435 						      SHOST_DIX_TYPE2_PROTECTION : 0) |
436 	       ((prot_caps & IB_PROT_T10DIF_TYPE_3) ? SHOST_DIF_TYPE3_PROTECTION |
437 						      SHOST_DIX_TYPE3_PROTECTION : 0);
438 }
439 
440 static struct iscsi_cls_session *
441 iscsi_iser_session_create(struct iscsi_endpoint *ep,
442 			  uint16_t cmds_max, uint16_t qdepth,
443 			  uint32_t initial_cmdsn)
444 {
445 	struct iscsi_cls_session *cls_session;
446 	struct iscsi_session *session;
447 	struct Scsi_Host *shost;
448 	struct iser_conn *ib_conn = NULL;
449 
450 	shost = iscsi_host_alloc(&iscsi_iser_sht, 0, 0);
451 	if (!shost)
452 		return NULL;
453 	shost->transportt = iscsi_iser_scsi_transport;
454 	shost->cmd_per_lun = qdepth;
455 	shost->max_lun = iscsi_max_lun;
456 	shost->max_id = 0;
457 	shost->max_channel = 0;
458 	shost->max_cmd_len = 16;
459 
460 	/*
461 	 * older userspace tools (before 2.0-870) did not pass us
462 	 * the leading conn's ep so this will be NULL;
463 	 */
464 	if (ep) {
465 		ib_conn = ep->dd_data;
466 		if (ib_conn->pi_support) {
467 			u32 sig_caps = ib_conn->device->dev_attr.sig_prot_cap;
468 
469 			scsi_host_set_prot(shost, iser_dif_prot_caps(sig_caps));
470 			if (iser_pi_guard)
471 				scsi_host_set_guard(shost, SHOST_DIX_GUARD_IP);
472 			else
473 				scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC);
474 		}
475 	}
476 
477 	if (iscsi_host_add(shost,
478 			   ep ? ib_conn->device->ib_device->dma_device : NULL))
479 		goto free_host;
480 
481 	if (cmds_max > ISER_DEF_XMIT_CMDS_MAX) {
482 		iser_info("cmds_max changed from %u to %u\n",
483 			  cmds_max, ISER_DEF_XMIT_CMDS_MAX);
484 		cmds_max = ISER_DEF_XMIT_CMDS_MAX;
485 	}
486 
487 	cls_session = iscsi_session_setup(&iscsi_iser_transport, shost,
488 					  cmds_max, 0,
489 					  sizeof(struct iscsi_iser_task),
490 					  initial_cmdsn, 0);
491 	if (!cls_session)
492 		goto remove_host;
493 	session = cls_session->dd_data;
494 
495 	shost->can_queue = session->scsi_cmds_max;
496 	return cls_session;
497 
498 remove_host:
499 	iscsi_host_remove(shost);
500 free_host:
501 	iscsi_host_free(shost);
502 	return NULL;
503 }
504 
505 static int
506 iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,
507 		     enum iscsi_param param, char *buf, int buflen)
508 {
509 	int value;
510 
511 	switch (param) {
512 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
513 		/* TBD */
514 		break;
515 	case ISCSI_PARAM_HDRDGST_EN:
516 		sscanf(buf, "%d", &value);
517 		if (value) {
518 			iser_err("DataDigest wasn't negotiated to None");
519 			return -EPROTO;
520 		}
521 		break;
522 	case ISCSI_PARAM_DATADGST_EN:
523 		sscanf(buf, "%d", &value);
524 		if (value) {
525 			iser_err("DataDigest wasn't negotiated to None");
526 			return -EPROTO;
527 		}
528 		break;
529 	case ISCSI_PARAM_IFMARKER_EN:
530 		sscanf(buf, "%d", &value);
531 		if (value) {
532 			iser_err("IFMarker wasn't negotiated to No");
533 			return -EPROTO;
534 		}
535 		break;
536 	case ISCSI_PARAM_OFMARKER_EN:
537 		sscanf(buf, "%d", &value);
538 		if (value) {
539 			iser_err("OFMarker wasn't negotiated to No");
540 			return -EPROTO;
541 		}
542 		break;
543 	default:
544 		return iscsi_set_param(cls_conn, param, buf, buflen);
545 	}
546 
547 	return 0;
548 }
549 
550 static void
551 iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
552 {
553 	struct iscsi_conn *conn = cls_conn->dd_data;
554 
555 	stats->txdata_octets = conn->txdata_octets;
556 	stats->rxdata_octets = conn->rxdata_octets;
557 	stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
558 	stats->dataout_pdus = conn->dataout_pdus_cnt;
559 	stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
560 	stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */
561 	stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
562 	stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
563 	stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
564 	stats->custom_length = 4;
565 	strcpy(stats->custom[0].desc, "qp_tx_queue_full");
566 	stats->custom[0].value = 0; /* TB iser_conn->qp_tx_queue_full; */
567 	strcpy(stats->custom[1].desc, "fmr_map_not_avail");
568 	stats->custom[1].value = 0; /* TB iser_conn->fmr_map_not_avail */;
569 	strcpy(stats->custom[2].desc, "eh_abort_cnt");
570 	stats->custom[2].value = conn->eh_abort_cnt;
571 	strcpy(stats->custom[3].desc, "fmr_unalign_cnt");
572 	stats->custom[3].value = conn->fmr_unalign_cnt;
573 }
574 
575 static int iscsi_iser_get_ep_param(struct iscsi_endpoint *ep,
576 				   enum iscsi_param param, char *buf)
577 {
578 	struct iser_conn *ib_conn = ep->dd_data;
579 	int len;
580 
581 	switch (param) {
582 	case ISCSI_PARAM_CONN_PORT:
583 	case ISCSI_PARAM_CONN_ADDRESS:
584 		if (!ib_conn || !ib_conn->cma_id)
585 			return -ENOTCONN;
586 
587 		return iscsi_conn_get_addr_param((struct sockaddr_storage *)
588 					&ib_conn->cma_id->route.addr.dst_addr,
589 					param, buf);
590 		break;
591 	default:
592 		return -ENOSYS;
593 	}
594 
595 	return len;
596 }
597 
598 static struct iscsi_endpoint *
599 iscsi_iser_ep_connect(struct Scsi_Host *shost, struct sockaddr *dst_addr,
600 		      int non_blocking)
601 {
602 	int err;
603 	struct iser_conn *ib_conn;
604 	struct iscsi_endpoint *ep;
605 
606 	ep = iscsi_create_endpoint(sizeof(*ib_conn));
607 	if (!ep)
608 		return ERR_PTR(-ENOMEM);
609 
610 	ib_conn = ep->dd_data;
611 	ib_conn->ep = ep;
612 	iser_conn_init(ib_conn);
613 
614 	err = iser_connect(ib_conn, NULL, (struct sockaddr_in *)dst_addr,
615 			   non_blocking);
616 	if (err)
617 		return ERR_PTR(err);
618 
619 	return ep;
620 }
621 
622 static int
623 iscsi_iser_ep_poll(struct iscsi_endpoint *ep, int timeout_ms)
624 {
625 	struct iser_conn *ib_conn;
626 	int rc;
627 
628 	ib_conn = ep->dd_data;
629 	rc = wait_event_interruptible_timeout(ib_conn->wait,
630 			     ib_conn->state == ISER_CONN_UP,
631 			     msecs_to_jiffies(timeout_ms));
632 
633 	/* if conn establishment failed, return error code to iscsi */
634 	if (!rc &&
635 	    (ib_conn->state == ISER_CONN_TERMINATING ||
636 	     ib_conn->state == ISER_CONN_DOWN))
637 		rc = -1;
638 
639 	iser_info("ib conn %p rc = %d\n", ib_conn, rc);
640 
641 	if (rc > 0)
642 		return 1; /* success, this is the equivalent of POLLOUT */
643 	else if (!rc)
644 		return 0; /* timeout */
645 	else
646 		return rc; /* signal */
647 }
648 
649 static void
650 iscsi_iser_ep_disconnect(struct iscsi_endpoint *ep)
651 {
652 	struct iser_conn *ib_conn;
653 
654 	ib_conn = ep->dd_data;
655 	if (ib_conn->iscsi_conn)
656 		/*
657 		 * Must suspend xmit path if the ep is bound to the
658 		 * iscsi_conn, so we know we are not accessing the ib_conn
659 		 * when we free it.
660 		 *
661 		 * This may not be bound if the ep poll failed.
662 		 */
663 		iscsi_suspend_tx(ib_conn->iscsi_conn);
664 
665 
666 	iser_info("ib conn %p state %d\n", ib_conn, ib_conn->state);
667 	iser_conn_terminate(ib_conn);
668 }
669 
670 static umode_t iser_attr_is_visible(int param_type, int param)
671 {
672 	switch (param_type) {
673 	case ISCSI_HOST_PARAM:
674 		switch (param) {
675 		case ISCSI_HOST_PARAM_NETDEV_NAME:
676 		case ISCSI_HOST_PARAM_HWADDRESS:
677 		case ISCSI_HOST_PARAM_INITIATOR_NAME:
678 			return S_IRUGO;
679 		default:
680 			return 0;
681 		}
682 	case ISCSI_PARAM:
683 		switch (param) {
684 		case ISCSI_PARAM_MAX_RECV_DLENGTH:
685 		case ISCSI_PARAM_MAX_XMIT_DLENGTH:
686 		case ISCSI_PARAM_HDRDGST_EN:
687 		case ISCSI_PARAM_DATADGST_EN:
688 		case ISCSI_PARAM_CONN_ADDRESS:
689 		case ISCSI_PARAM_CONN_PORT:
690 		case ISCSI_PARAM_EXP_STATSN:
691 		case ISCSI_PARAM_PERSISTENT_ADDRESS:
692 		case ISCSI_PARAM_PERSISTENT_PORT:
693 		case ISCSI_PARAM_PING_TMO:
694 		case ISCSI_PARAM_RECV_TMO:
695 		case ISCSI_PARAM_INITIAL_R2T_EN:
696 		case ISCSI_PARAM_MAX_R2T:
697 		case ISCSI_PARAM_IMM_DATA_EN:
698 		case ISCSI_PARAM_FIRST_BURST:
699 		case ISCSI_PARAM_MAX_BURST:
700 		case ISCSI_PARAM_PDU_INORDER_EN:
701 		case ISCSI_PARAM_DATASEQ_INORDER_EN:
702 		case ISCSI_PARAM_TARGET_NAME:
703 		case ISCSI_PARAM_TPGT:
704 		case ISCSI_PARAM_USERNAME:
705 		case ISCSI_PARAM_PASSWORD:
706 		case ISCSI_PARAM_USERNAME_IN:
707 		case ISCSI_PARAM_PASSWORD_IN:
708 		case ISCSI_PARAM_FAST_ABORT:
709 		case ISCSI_PARAM_ABORT_TMO:
710 		case ISCSI_PARAM_LU_RESET_TMO:
711 		case ISCSI_PARAM_TGT_RESET_TMO:
712 		case ISCSI_PARAM_IFACE_NAME:
713 		case ISCSI_PARAM_INITIATOR_NAME:
714 		case ISCSI_PARAM_DISCOVERY_SESS:
715 			return S_IRUGO;
716 		default:
717 			return 0;
718 		}
719 	}
720 
721 	return 0;
722 }
723 
724 static struct scsi_host_template iscsi_iser_sht = {
725 	.module                 = THIS_MODULE,
726 	.name                   = "iSCSI Initiator over iSER",
727 	.queuecommand           = iscsi_queuecommand,
728 	.change_queue_depth	= iscsi_change_queue_depth,
729 	.sg_tablesize           = ISCSI_ISER_SG_TABLESIZE,
730 	.max_sectors		= 1024,
731 	.cmd_per_lun            = ISER_DEF_CMD_PER_LUN,
732 	.eh_abort_handler       = iscsi_eh_abort,
733 	.eh_device_reset_handler= iscsi_eh_device_reset,
734 	.eh_target_reset_handler = iscsi_eh_recover_target,
735 	.target_alloc		= iscsi_target_alloc,
736 	.use_clustering         = DISABLE_CLUSTERING,
737 	.proc_name              = "iscsi_iser",
738 	.this_id                = -1,
739 };
740 
741 static struct iscsi_transport iscsi_iser_transport = {
742 	.owner                  = THIS_MODULE,
743 	.name                   = "iser",
744 	.caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_TEXT_NEGO,
745 	/* session management */
746 	.create_session         = iscsi_iser_session_create,
747 	.destroy_session        = iscsi_iser_session_destroy,
748 	/* connection management */
749 	.create_conn            = iscsi_iser_conn_create,
750 	.bind_conn              = iscsi_iser_conn_bind,
751 	.destroy_conn           = iscsi_iser_conn_destroy,
752 	.attr_is_visible	= iser_attr_is_visible,
753 	.set_param              = iscsi_iser_set_param,
754 	.get_conn_param		= iscsi_conn_get_param,
755 	.get_ep_param		= iscsi_iser_get_ep_param,
756 	.get_session_param	= iscsi_session_get_param,
757 	.start_conn             = iscsi_conn_start,
758 	.stop_conn              = iscsi_iser_conn_stop,
759 	/* iscsi host params */
760 	.get_host_param		= iscsi_host_get_param,
761 	.set_host_param		= iscsi_host_set_param,
762 	/* IO */
763 	.send_pdu		= iscsi_conn_send_pdu,
764 	.get_stats		= iscsi_iser_conn_get_stats,
765 	.init_task		= iscsi_iser_task_init,
766 	.xmit_task		= iscsi_iser_task_xmit,
767 	.cleanup_task		= iscsi_iser_cleanup_task,
768 	.alloc_pdu		= iscsi_iser_pdu_alloc,
769 	.check_protection	= iscsi_iser_check_protection,
770 	/* recovery */
771 	.session_recovery_timedout = iscsi_session_recovery_timedout,
772 
773 	.ep_connect             = iscsi_iser_ep_connect,
774 	.ep_poll                = iscsi_iser_ep_poll,
775 	.ep_disconnect          = iscsi_iser_ep_disconnect
776 };
777 
778 static int __init iser_init(void)
779 {
780 	int err;
781 
782 	iser_dbg("Starting iSER datamover...\n");
783 
784 	if (iscsi_max_lun < 1) {
785 		iser_err("Invalid max_lun value of %u\n", iscsi_max_lun);
786 		return -EINVAL;
787 	}
788 
789 	memset(&ig, 0, sizeof(struct iser_global));
790 
791 	ig.desc_cache = kmem_cache_create("iser_descriptors",
792 					  sizeof(struct iser_tx_desc),
793 					  0, SLAB_HWCACHE_ALIGN,
794 					  NULL);
795 	if (ig.desc_cache == NULL)
796 		return -ENOMEM;
797 
798 	/* device init is called only after the first addr resolution */
799 	mutex_init(&ig.device_list_mutex);
800 	INIT_LIST_HEAD(&ig.device_list);
801 	mutex_init(&ig.connlist_mutex);
802 	INIT_LIST_HEAD(&ig.connlist);
803 
804 	iscsi_iser_scsi_transport = iscsi_register_transport(
805 							&iscsi_iser_transport);
806 	if (!iscsi_iser_scsi_transport) {
807 		iser_err("iscsi_register_transport failed\n");
808 		err = -EINVAL;
809 		goto register_transport_failure;
810 	}
811 
812 	return 0;
813 
814 register_transport_failure:
815 	kmem_cache_destroy(ig.desc_cache);
816 
817 	return err;
818 }
819 
820 static void __exit iser_exit(void)
821 {
822 	iser_dbg("Removing iSER datamover...\n");
823 	iscsi_unregister_transport(&iscsi_iser_transport);
824 	kmem_cache_destroy(ig.desc_cache);
825 }
826 
827 module_init(iser_init);
828 module_exit(iser_exit);
829