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
77static struct scsi_host_template iscsi_iser_sht;
78static struct iscsi_transport iscsi_iser_transport;
79static struct scsi_transport_template *iscsi_iser_scsi_transport;
80
81static unsigned int iscsi_max_lun = 512;
82module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
83
84int iser_debug_level = 0;
85bool iser_pi_enable = false;
86int iser_pi_guard = 1;
87
88MODULE_DESCRIPTION("iSER (iSCSI Extensions for RDMA) Datamover");
89MODULE_LICENSE("Dual BSD/GPL");
90MODULE_AUTHOR("Alex Nezhinsky, Dan Bar Dov, Or Gerlitz");
91MODULE_VERSION(DRV_VER);
92
93module_param_named(debug_level, iser_debug_level, int, 0644);
94MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:disabled)");
95
96module_param_named(pi_enable, iser_pi_enable, bool, 0644);
97MODULE_PARM_DESC(pi_enable, "Enable T10-PI offload support (default:disabled)");
98
99module_param_named(pi_guard, iser_pi_guard, int, 0644);
100MODULE_PARM_DESC(pi_guard, "T10-PI guard_type [deprecated]");
101
102static struct workqueue_struct *release_wq;
103struct iser_global ig;
104
105/*
106 * iscsi_iser_recv() - Process a successfull recv completion
107 * @conn:         iscsi connection
108 * @hdr:          iscsi header
109 * @rx_data:      buffer containing receive data payload
110 * @rx_data_len:  length of rx_data
111 *
112 * Notes: In case of data length errors or iscsi PDU completion failures
113 *        this routine will signal iscsi layer of connection failure.
114 */
115void
116iscsi_iser_recv(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
117		char *rx_data, int rx_data_len)
118{
119	int rc = 0;
120	int datalen;
121	int ahslen;
122
123	/* verify PDU length */
124	datalen = ntoh24(hdr->dlength);
125	if (datalen > rx_data_len || (datalen + 4) < rx_data_len) {
126		iser_err("wrong datalen %d (hdr), %d (IB)\n",
127			datalen, rx_data_len);
128		rc = ISCSI_ERR_DATALEN;
129		goto error;
130	}
131
132	if (datalen != rx_data_len)
133		iser_dbg("aligned datalen (%d) hdr, %d (IB)\n",
134			datalen, rx_data_len);
135
136	/* read AHS */
137	ahslen = hdr->hlength * 4;
138
139	rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
140	if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
141		goto error;
142
143	return;
144error:
145	iscsi_conn_failure(conn, rc);
146}
147
148/**
149 * iscsi_iser_pdu_alloc() - allocate an iscsi-iser PDU
150 * @task:     iscsi task
151 * @opcode:   iscsi command opcode
152 *
153 * Netes: This routine can't fail, just assign iscsi task
154 *        hdr and max hdr size.
155 */
156static int
157iscsi_iser_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
158{
159	struct iscsi_iser_task *iser_task = task->dd_data;
160
161	task->hdr = (struct iscsi_hdr *)&iser_task->desc.iscsi_header;
162	task->hdr_max = sizeof(iser_task->desc.iscsi_header);
163
164	return 0;
165}
166
167/**
168 * iser_initialize_task_headers() - Initialize task headers
169 * @task:       iscsi task
170 * @tx_desc:    iser tx descriptor
171 *
172 * Notes:
173 * This routine may race with iser teardown flow for scsi
174 * error handling TMFs. So for TMF we should acquire the
175 * state mutex to avoid dereferencing the IB device which
176 * may have already been terminated.
177 */
178int
179iser_initialize_task_headers(struct iscsi_task *task,
180			     struct iser_tx_desc *tx_desc)
181{
182	struct iser_conn *iser_conn = task->conn->dd_data;
183	struct iser_device *device = iser_conn->ib_conn.device;
184	struct iscsi_iser_task *iser_task = task->dd_data;
185	u64 dma_addr;
186	const bool mgmt_task = !task->sc && !in_interrupt();
187	int ret = 0;
188
189	if (unlikely(mgmt_task))
190		mutex_lock(&iser_conn->state_mutex);
191
192	if (unlikely(iser_conn->state != ISER_CONN_UP)) {
193		ret = -ENODEV;
194		goto out;
195	}
196
197	dma_addr = ib_dma_map_single(device->ib_device, (void *)tx_desc,
198				ISER_HEADERS_LEN, DMA_TO_DEVICE);
199	if (ib_dma_mapping_error(device->ib_device, dma_addr)) {
200		ret = -ENOMEM;
201		goto out;
202	}
203
204	tx_desc->mapped = true;
205	tx_desc->dma_addr = dma_addr;
206	tx_desc->tx_sg[0].addr   = tx_desc->dma_addr;
207	tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;
208	tx_desc->tx_sg[0].lkey   = device->mr->lkey;
209
210	iser_task->iser_conn = iser_conn;
211out:
212	if (unlikely(mgmt_task))
213		mutex_unlock(&iser_conn->state_mutex);
214
215	return ret;
216}
217
218/**
219 * iscsi_iser_task_init() - Initialize iscsi-iser task
220 * @task: iscsi task
221 *
222 * Initialize the task for the scsi command or mgmt command.
223 *
224 * Return: Returns zero on success or -ENOMEM when failing
225 *         to init task headers (dma mapping error).
226 */
227static int
228iscsi_iser_task_init(struct iscsi_task *task)
229{
230	struct iscsi_iser_task *iser_task = task->dd_data;
231	int ret;
232
233	ret = iser_initialize_task_headers(task, &iser_task->desc);
234	if (ret) {
235		iser_err("Failed to init task %p, err = %d\n",
236			 iser_task, ret);
237		return ret;
238	}
239
240	/* mgmt task */
241	if (!task->sc)
242		return 0;
243
244	iser_task->command_sent = 0;
245	iser_task_rdma_init(iser_task);
246	iser_task->sc = task->sc;
247
248	return 0;
249}
250
251/**
252 * iscsi_iser_mtask_xmit() - xmit management (immediate) task
253 * @conn: iscsi connection
254 * @task: task management task
255 *
256 * Notes:
257 *	The function can return -EAGAIN in which case caller must
258 *	call it again later, or recover. '0' return code means successful
259 *	xmit.
260 *
261 **/
262static int
263iscsi_iser_mtask_xmit(struct iscsi_conn *conn, struct iscsi_task *task)
264{
265	int error = 0;
266
267	iser_dbg("mtask xmit [cid %d itt 0x%x]\n", conn->id, task->itt);
268
269	error = iser_send_control(conn, task);
270
271	/* since iser xmits control with zero copy, tasks can not be recycled
272	 * right after sending them.
273	 * The recycling scheme is based on whether a response is expected
274	 * - if yes, the task is recycled at iscsi_complete_pdu
275	 * - if no,  the task is recycled at iser_snd_completion
276	 */
277	return error;
278}
279
280static int
281iscsi_iser_task_xmit_unsol_data(struct iscsi_conn *conn,
282				 struct iscsi_task *task)
283{
284	struct iscsi_r2t_info *r2t = &task->unsol_r2t;
285	struct iscsi_data hdr;
286	int error = 0;
287
288	/* Send data-out PDUs while there's still unsolicited data to send */
289	while (iscsi_task_has_unsol_data(task)) {
290		iscsi_prep_data_out_pdu(task, r2t, &hdr);
291		iser_dbg("Sending data-out: itt 0x%x, data count %d\n",
292			   hdr.itt, r2t->data_count);
293
294		/* the buffer description has been passed with the command */
295		/* Send the command */
296		error = iser_send_data_out(conn, task, &hdr);
297		if (error) {
298			r2t->datasn--;
299			goto iscsi_iser_task_xmit_unsol_data_exit;
300		}
301		r2t->sent += r2t->data_count;
302		iser_dbg("Need to send %d more as data-out PDUs\n",
303			   r2t->data_length - r2t->sent);
304	}
305
306iscsi_iser_task_xmit_unsol_data_exit:
307	return error;
308}
309
310/**
311 * iscsi_iser_task_xmit() - xmit iscsi-iser task
312 * @task: iscsi task
313 *
314 * Return: zero on success or escalates $error on failure.
315 */
316static int
317iscsi_iser_task_xmit(struct iscsi_task *task)
318{
319	struct iscsi_conn *conn = task->conn;
320	struct iscsi_iser_task *iser_task = task->dd_data;
321	int error = 0;
322
323	if (!task->sc)
324		return iscsi_iser_mtask_xmit(conn, task);
325
326	if (task->sc->sc_data_direction == DMA_TO_DEVICE) {
327		BUG_ON(scsi_bufflen(task->sc) == 0);
328
329		iser_dbg("cmd [itt %x total %d imm %d unsol_data %d\n",
330			   task->itt, scsi_bufflen(task->sc),
331			   task->imm_count, task->unsol_r2t.data_length);
332	}
333
334	iser_dbg("ctask xmit [cid %d itt 0x%x]\n",
335		   conn->id, task->itt);
336
337	/* Send the cmd PDU */
338	if (!iser_task->command_sent) {
339		error = iser_send_command(conn, task);
340		if (error)
341			goto iscsi_iser_task_xmit_exit;
342		iser_task->command_sent = 1;
343	}
344
345	/* Send unsolicited data-out PDU(s) if necessary */
346	if (iscsi_task_has_unsol_data(task))
347		error = iscsi_iser_task_xmit_unsol_data(conn, task);
348
349 iscsi_iser_task_xmit_exit:
350	return error;
351}
352
353/**
354 * iscsi_iser_cleanup_task() - cleanup an iscsi-iser task
355 * @task: iscsi task
356 *
357 * Notes: In case the RDMA device is already NULL (might have
358 *        been removed in DEVICE_REMOVAL CM event it will bail-out
359 *        without doing dma unmapping.
360 */
361static void iscsi_iser_cleanup_task(struct iscsi_task *task)
362{
363	struct iscsi_iser_task *iser_task = task->dd_data;
364	struct iser_tx_desc *tx_desc = &iser_task->desc;
365	struct iser_conn *iser_conn = task->conn->dd_data;
366	struct iser_device *device = iser_conn->ib_conn.device;
367
368	/* DEVICE_REMOVAL event might have already released the device */
369	if (!device)
370		return;
371
372	if (likely(tx_desc->mapped)) {
373		ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
374				    ISER_HEADERS_LEN, DMA_TO_DEVICE);
375		tx_desc->mapped = false;
376	}
377
378	/* mgmt tasks do not need special cleanup */
379	if (!task->sc)
380		return;
381
382	if (iser_task->status == ISER_TASK_STATUS_STARTED) {
383		iser_task->status = ISER_TASK_STATUS_COMPLETED;
384		iser_task_rdma_finalize(iser_task);
385	}
386}
387
388/**
389 * iscsi_iser_check_protection() - check protection information status of task.
390 * @task:     iscsi task
391 * @sector:   error sector if exsists (output)
392 *
393 * Return: zero if no data-integrity errors have occured
394 *         0x1: data-integrity error occured in the guard-block
395 *         0x2: data-integrity error occured in the reference tag
396 *         0x3: data-integrity error occured in the application tag
397 *
398 *         In addition the error sector is marked.
399 */
400static u8
401iscsi_iser_check_protection(struct iscsi_task *task, sector_t *sector)
402{
403	struct iscsi_iser_task *iser_task = task->dd_data;
404
405	if (iser_task->dir[ISER_DIR_IN])
406		return iser_check_task_pi_status(iser_task, ISER_DIR_IN,
407						 sector);
408	else
409		return iser_check_task_pi_status(iser_task, ISER_DIR_OUT,
410						 sector);
411}
412
413/**
414 * iscsi_iser_conn_create() - create a new iscsi-iser connection
415 * @cls_session: iscsi class connection
416 * @conn_idx:    connection index within the session (for MCS)
417 *
418 * Return: iscsi_cls_conn when iscsi_conn_setup succeeds or NULL
419 *         otherwise.
420 */
421static struct iscsi_cls_conn *
422iscsi_iser_conn_create(struct iscsi_cls_session *cls_session,
423		       uint32_t conn_idx)
424{
425	struct iscsi_conn *conn;
426	struct iscsi_cls_conn *cls_conn;
427
428	cls_conn = iscsi_conn_setup(cls_session, 0, conn_idx);
429	if (!cls_conn)
430		return NULL;
431	conn = cls_conn->dd_data;
432
433	/*
434	 * due to issues with the login code re iser sematics
435	 * this not set in iscsi_conn_setup - FIXME
436	 */
437	conn->max_recv_dlength = ISER_RECV_DATA_SEG_LEN;
438
439	return cls_conn;
440}
441
442/**
443 * iscsi_iser_conn_bind() - bind iscsi and iser connection structures
444 * @cls_session:     iscsi class session
445 * @cls_conn:        iscsi class connection
446 * @transport_eph:   transport end-point handle
447 * @is_leading:      indicate if this is the session leading connection (MCS)
448 *
449 * Return: zero on success, $error if iscsi_conn_bind fails and
450 *         -EINVAL in case end-point doesn't exsits anymore or iser connection
451 *         state is not UP (teardown already started).
452 */
453static int
454iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
455		     struct iscsi_cls_conn *cls_conn,
456		     uint64_t transport_eph,
457		     int is_leading)
458{
459	struct iscsi_conn *conn = cls_conn->dd_data;
460	struct iser_conn *iser_conn;
461	struct iscsi_endpoint *ep;
462	int error;
463
464	error = iscsi_conn_bind(cls_session, cls_conn, is_leading);
465	if (error)
466		return error;
467
468	/* the transport ep handle comes from user space so it must be
469	 * verified against the global ib connections list */
470	ep = iscsi_lookup_endpoint(transport_eph);
471	if (!ep) {
472		iser_err("can't bind eph %llx\n",
473			 (unsigned long long)transport_eph);
474		return -EINVAL;
475	}
476	iser_conn = ep->dd_data;
477
478	mutex_lock(&iser_conn->state_mutex);
479	if (iser_conn->state != ISER_CONN_UP) {
480		error = -EINVAL;
481		iser_err("iser_conn %p state is %d, teardown started\n",
482			 iser_conn, iser_conn->state);
483		goto out;
484	}
485
486	error = iser_alloc_rx_descriptors(iser_conn, conn->session);
487	if (error)
488		goto out;
489
490	/* binds the iSER connection retrieved from the previously
491	 * connected ep_handle to the iSCSI layer connection. exchanges
492	 * connection pointers */
493	iser_info("binding iscsi conn %p to iser_conn %p\n", conn, iser_conn);
494
495	conn->dd_data = iser_conn;
496	iser_conn->iscsi_conn = conn;
497
498out:
499	mutex_unlock(&iser_conn->state_mutex);
500	return error;
501}
502
503/**
504 * iscsi_iser_conn_start() - start iscsi-iser connection
505 * @cls_conn: iscsi class connection
506 *
507 * Notes: Here iser intialize (or re-initialize) stop_completion as
508 *        from this point iscsi must call conn_stop in session/connection
509 *        teardown so iser transport must wait for it.
510 */
511static int
512iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn)
513{
514	struct iscsi_conn *iscsi_conn;
515	struct iser_conn *iser_conn;
516
517	iscsi_conn = cls_conn->dd_data;
518	iser_conn = iscsi_conn->dd_data;
519	reinit_completion(&iser_conn->stop_completion);
520
521	return iscsi_conn_start(cls_conn);
522}
523
524/**
525 * iscsi_iser_conn_stop() - stop iscsi-iser connection
526 * @cls_conn:  iscsi class connection
527 * @flag:      indicate if recover or terminate (passed as is)
528 *
529 * Notes: Calling iscsi_conn_stop might theoretically race with
530 *        DEVICE_REMOVAL event and dereference a previously freed RDMA device
531 *        handle, so we call it under iser the state lock to protect against
532 *        this kind of race.
533 */
534static void
535iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
536{
537	struct iscsi_conn *conn = cls_conn->dd_data;
538	struct iser_conn *iser_conn = conn->dd_data;
539
540	iser_info("stopping iscsi_conn: %p, iser_conn: %p\n", conn, iser_conn);
541
542	/*
543	 * Userspace may have goofed up and not bound the connection or
544	 * might have only partially setup the connection.
545	 */
546	if (iser_conn) {
547		mutex_lock(&iser_conn->state_mutex);
548		iser_conn_terminate(iser_conn);
549		iscsi_conn_stop(cls_conn, flag);
550
551		/* unbind */
552		iser_conn->iscsi_conn = NULL;
553		conn->dd_data = NULL;
554
555		complete(&iser_conn->stop_completion);
556		mutex_unlock(&iser_conn->state_mutex);
557	} else {
558		iscsi_conn_stop(cls_conn, flag);
559	}
560}
561
562/**
563 * iscsi_iser_session_destroy() - destroy iscsi-iser session
564 * @cls_session: iscsi class session
565 *
566 * Removes and free iscsi host.
567 */
568static void
569iscsi_iser_session_destroy(struct iscsi_cls_session *cls_session)
570{
571	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
572
573	iscsi_session_teardown(cls_session);
574	iscsi_host_remove(shost);
575	iscsi_host_free(shost);
576}
577
578static inline unsigned int
579iser_dif_prot_caps(int prot_caps)
580{
581	return ((prot_caps & IB_PROT_T10DIF_TYPE_1) ?
582		SHOST_DIF_TYPE1_PROTECTION | SHOST_DIX_TYPE0_PROTECTION |
583		SHOST_DIX_TYPE1_PROTECTION : 0) |
584	       ((prot_caps & IB_PROT_T10DIF_TYPE_2) ?
585		SHOST_DIF_TYPE2_PROTECTION | SHOST_DIX_TYPE2_PROTECTION : 0) |
586	       ((prot_caps & IB_PROT_T10DIF_TYPE_3) ?
587		SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE3_PROTECTION : 0);
588}
589
590/**
591 * iscsi_iser_session_create() - create an iscsi-iser session
592 * @ep:             iscsi end-point handle
593 * @cmds_max:       maximum commands in this session
594 * @qdepth:         session command queue depth
595 * @initial_cmdsn:  initiator command sequnce number
596 *
597 * Allocates and adds a scsi host, expose DIF supprot if
598 * exists, and sets up an iscsi session.
599 */
600static struct iscsi_cls_session *
601iscsi_iser_session_create(struct iscsi_endpoint *ep,
602			  uint16_t cmds_max, uint16_t qdepth,
603			  uint32_t initial_cmdsn)
604{
605	struct iscsi_cls_session *cls_session;
606	struct iscsi_session *session;
607	struct Scsi_Host *shost;
608	struct iser_conn *iser_conn = NULL;
609	struct ib_conn *ib_conn;
610	u16 max_cmds;
611
612	shost = iscsi_host_alloc(&iscsi_iser_sht, 0, 0);
613	if (!shost)
614		return NULL;
615	shost->transportt = iscsi_iser_scsi_transport;
616	shost->cmd_per_lun = qdepth;
617	shost->max_lun = iscsi_max_lun;
618	shost->max_id = 0;
619	shost->max_channel = 0;
620	shost->max_cmd_len = 16;
621
622	/*
623	 * older userspace tools (before 2.0-870) did not pass us
624	 * the leading conn's ep so this will be NULL;
625	 */
626	if (ep) {
627		iser_conn = ep->dd_data;
628		max_cmds = iser_conn->max_cmds;
629
630		mutex_lock(&iser_conn->state_mutex);
631		if (iser_conn->state != ISER_CONN_UP) {
632			iser_err("iser conn %p already started teardown\n",
633				 iser_conn);
634			mutex_unlock(&iser_conn->state_mutex);
635			goto free_host;
636		}
637
638		ib_conn = &iser_conn->ib_conn;
639		if (ib_conn->pi_support) {
640			u32 sig_caps = ib_conn->device->dev_attr.sig_prot_cap;
641
642			scsi_host_set_prot(shost, iser_dif_prot_caps(sig_caps));
643			scsi_host_set_guard(shost, SHOST_DIX_GUARD_IP |
644						   SHOST_DIX_GUARD_CRC);
645		}
646
647		if (iscsi_host_add(shost,
648				   ib_conn->device->ib_device->dma_device)) {
649			mutex_unlock(&iser_conn->state_mutex);
650			goto free_host;
651		}
652		mutex_unlock(&iser_conn->state_mutex);
653	} else {
654		max_cmds = ISER_DEF_XMIT_CMDS_MAX;
655		if (iscsi_host_add(shost, NULL))
656			goto free_host;
657	}
658
659	if (cmds_max > max_cmds) {
660		iser_info("cmds_max changed from %u to %u\n",
661			  cmds_max, max_cmds);
662		cmds_max = max_cmds;
663	}
664
665	cls_session = iscsi_session_setup(&iscsi_iser_transport, shost,
666					  cmds_max, 0,
667					  sizeof(struct iscsi_iser_task),
668					  initial_cmdsn, 0);
669	if (!cls_session)
670		goto remove_host;
671	session = cls_session->dd_data;
672
673	shost->can_queue = session->scsi_cmds_max;
674	return cls_session;
675
676remove_host:
677	iscsi_host_remove(shost);
678free_host:
679	iscsi_host_free(shost);
680	return NULL;
681}
682
683static int
684iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,
685		     enum iscsi_param param, char *buf, int buflen)
686{
687	int value;
688
689	switch (param) {
690	case ISCSI_PARAM_MAX_RECV_DLENGTH:
691		/* TBD */
692		break;
693	case ISCSI_PARAM_HDRDGST_EN:
694		sscanf(buf, "%d", &value);
695		if (value) {
696			iser_err("DataDigest wasn't negotiated to None\n");
697			return -EPROTO;
698		}
699		break;
700	case ISCSI_PARAM_DATADGST_EN:
701		sscanf(buf, "%d", &value);
702		if (value) {
703			iser_err("DataDigest wasn't negotiated to None\n");
704			return -EPROTO;
705		}
706		break;
707	case ISCSI_PARAM_IFMARKER_EN:
708		sscanf(buf, "%d", &value);
709		if (value) {
710			iser_err("IFMarker wasn't negotiated to No\n");
711			return -EPROTO;
712		}
713		break;
714	case ISCSI_PARAM_OFMARKER_EN:
715		sscanf(buf, "%d", &value);
716		if (value) {
717			iser_err("OFMarker wasn't negotiated to No\n");
718			return -EPROTO;
719		}
720		break;
721	default:
722		return iscsi_set_param(cls_conn, param, buf, buflen);
723	}
724
725	return 0;
726}
727
728/**
729 * iscsi_iser_set_param() - set class connection parameter
730 * @cls_conn:    iscsi class connection
731 * @stats:       iscsi stats to output
732 *
733 * Output connection statistics.
734 */
735static void
736iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
737{
738	struct iscsi_conn *conn = cls_conn->dd_data;
739
740	stats->txdata_octets = conn->txdata_octets;
741	stats->rxdata_octets = conn->rxdata_octets;
742	stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
743	stats->dataout_pdus = conn->dataout_pdus_cnt;
744	stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
745	stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */
746	stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
747	stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
748	stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
749	stats->custom_length = 4;
750	strcpy(stats->custom[0].desc, "qp_tx_queue_full");
751	stats->custom[0].value = 0; /* TB iser_conn->qp_tx_queue_full; */
752	strcpy(stats->custom[1].desc, "fmr_map_not_avail");
753	stats->custom[1].value = 0; /* TB iser_conn->fmr_map_not_avail */;
754	strcpy(stats->custom[2].desc, "eh_abort_cnt");
755	stats->custom[2].value = conn->eh_abort_cnt;
756	strcpy(stats->custom[3].desc, "fmr_unalign_cnt");
757	stats->custom[3].value = conn->fmr_unalign_cnt;
758}
759
760static int iscsi_iser_get_ep_param(struct iscsi_endpoint *ep,
761				   enum iscsi_param param, char *buf)
762{
763	struct iser_conn *iser_conn = ep->dd_data;
764	int len;
765
766	switch (param) {
767	case ISCSI_PARAM_CONN_PORT:
768	case ISCSI_PARAM_CONN_ADDRESS:
769		if (!iser_conn || !iser_conn->ib_conn.cma_id)
770			return -ENOTCONN;
771
772		return iscsi_conn_get_addr_param((struct sockaddr_storage *)
773				&iser_conn->ib_conn.cma_id->route.addr.dst_addr,
774				param, buf);
775		break;
776	default:
777		return -ENOSYS;
778	}
779
780	return len;
781}
782
783/**
784 * iscsi_iser_ep_connect() - Initiate iSER connection establishment
785 * @shost:          scsi_host
786 * @dst_addr:       destination address
787 * @non-blocking:   indicate if routine can block
788 *
789 * Allocate an iscsi endpoint, an iser_conn structure and bind them.
790 * After that start RDMA connection establishment via rdma_cm. We
791 * don't allocate iser_conn embedded in iscsi_endpoint since in teardown
792 * the endpoint will be destroyed at ep_disconnect while iser_conn will
793 * cleanup its resources asynchronuously.
794 *
795 * Return: iscsi_endpoint created by iscsi layer or ERR_PTR(error)
796 *         if fails.
797 */
798static struct iscsi_endpoint *
799iscsi_iser_ep_connect(struct Scsi_Host *shost, struct sockaddr *dst_addr,
800		      int non_blocking)
801{
802	int err;
803	struct iser_conn *iser_conn;
804	struct iscsi_endpoint *ep;
805
806	ep = iscsi_create_endpoint(0);
807	if (!ep)
808		return ERR_PTR(-ENOMEM);
809
810	iser_conn = kzalloc(sizeof(*iser_conn), GFP_KERNEL);
811	if (!iser_conn) {
812		err = -ENOMEM;
813		goto failure;
814	}
815
816	ep->dd_data = iser_conn;
817	iser_conn->ep = ep;
818	iser_conn_init(iser_conn);
819
820	err = iser_connect(iser_conn, NULL, dst_addr, non_blocking);
821	if (err)
822		goto failure;
823
824	return ep;
825failure:
826	iscsi_destroy_endpoint(ep);
827	return ERR_PTR(err);
828}
829
830/**
831 * iscsi_iser_ep_poll() - poll for iser connection establishment to complete
832 * @ep:            iscsi endpoint (created at ep_connect)
833 * @timeout_ms:    polling timeout allowed in ms.
834 *
835 * This routine boils down to waiting for up_completion signaling
836 * that cma_id got CONNECTED event.
837 *
838 * Return: 1 if succeeded in connection establishment, 0 if timeout expired
839 *         (libiscsi will retry will kick in) or -1 if interrupted by signal
840 *         or more likely iser connection state transitioned to TEMINATING or
841 *         DOWN during the wait period.
842 */
843static int
844iscsi_iser_ep_poll(struct iscsi_endpoint *ep, int timeout_ms)
845{
846	struct iser_conn *iser_conn;
847	int rc;
848
849	iser_conn = ep->dd_data;
850	rc = wait_for_completion_interruptible_timeout(&iser_conn->up_completion,
851						       msecs_to_jiffies(timeout_ms));
852	/* if conn establishment failed, return error code to iscsi */
853	if (rc == 0) {
854		mutex_lock(&iser_conn->state_mutex);
855		if (iser_conn->state == ISER_CONN_TERMINATING ||
856		    iser_conn->state == ISER_CONN_DOWN)
857			rc = -1;
858		mutex_unlock(&iser_conn->state_mutex);
859	}
860
861	iser_info("ib conn %p rc = %d\n", iser_conn, rc);
862
863	if (rc > 0)
864		return 1; /* success, this is the equivalent of POLLOUT */
865	else if (!rc)
866		return 0; /* timeout */
867	else
868		return rc; /* signal */
869}
870
871/**
872 * iscsi_iser_ep_disconnect() - Initiate connection teardown process
873 * @ep:    iscsi endpoint handle
874 *
875 * This routine is not blocked by iser and RDMA termination process
876 * completion as we queue a deffered work for iser/RDMA destruction
877 * and cleanup or actually call it immediately in case we didn't pass
878 * iscsi conn bind/start stage, thus it is safe.
879 */
880static void
881iscsi_iser_ep_disconnect(struct iscsi_endpoint *ep)
882{
883	struct iser_conn *iser_conn;
884
885	iser_conn = ep->dd_data;
886	iser_info("ep %p iser conn %p state %d\n",
887		  ep, iser_conn, iser_conn->state);
888
889	mutex_lock(&iser_conn->state_mutex);
890	iser_conn_terminate(iser_conn);
891
892	/*
893	 * if iser_conn and iscsi_conn are bound, we must wait for
894	 * iscsi_conn_stop and flush errors completion before freeing
895	 * the iser resources. Otherwise we are safe to free resources
896	 * immediately.
897	 */
898	if (iser_conn->iscsi_conn) {
899		INIT_WORK(&iser_conn->release_work, iser_release_work);
900		queue_work(release_wq, &iser_conn->release_work);
901		mutex_unlock(&iser_conn->state_mutex);
902	} else {
903		iser_conn->state = ISER_CONN_DOWN;
904		mutex_unlock(&iser_conn->state_mutex);
905		iser_conn_release(iser_conn);
906	}
907	iscsi_destroy_endpoint(ep);
908}
909
910static umode_t iser_attr_is_visible(int param_type, int param)
911{
912	switch (param_type) {
913	case ISCSI_HOST_PARAM:
914		switch (param) {
915		case ISCSI_HOST_PARAM_NETDEV_NAME:
916		case ISCSI_HOST_PARAM_HWADDRESS:
917		case ISCSI_HOST_PARAM_INITIATOR_NAME:
918			return S_IRUGO;
919		default:
920			return 0;
921		}
922	case ISCSI_PARAM:
923		switch (param) {
924		case ISCSI_PARAM_MAX_RECV_DLENGTH:
925		case ISCSI_PARAM_MAX_XMIT_DLENGTH:
926		case ISCSI_PARAM_HDRDGST_EN:
927		case ISCSI_PARAM_DATADGST_EN:
928		case ISCSI_PARAM_CONN_ADDRESS:
929		case ISCSI_PARAM_CONN_PORT:
930		case ISCSI_PARAM_EXP_STATSN:
931		case ISCSI_PARAM_PERSISTENT_ADDRESS:
932		case ISCSI_PARAM_PERSISTENT_PORT:
933		case ISCSI_PARAM_PING_TMO:
934		case ISCSI_PARAM_RECV_TMO:
935		case ISCSI_PARAM_INITIAL_R2T_EN:
936		case ISCSI_PARAM_MAX_R2T:
937		case ISCSI_PARAM_IMM_DATA_EN:
938		case ISCSI_PARAM_FIRST_BURST:
939		case ISCSI_PARAM_MAX_BURST:
940		case ISCSI_PARAM_PDU_INORDER_EN:
941		case ISCSI_PARAM_DATASEQ_INORDER_EN:
942		case ISCSI_PARAM_TARGET_NAME:
943		case ISCSI_PARAM_TPGT:
944		case ISCSI_PARAM_USERNAME:
945		case ISCSI_PARAM_PASSWORD:
946		case ISCSI_PARAM_USERNAME_IN:
947		case ISCSI_PARAM_PASSWORD_IN:
948		case ISCSI_PARAM_FAST_ABORT:
949		case ISCSI_PARAM_ABORT_TMO:
950		case ISCSI_PARAM_LU_RESET_TMO:
951		case ISCSI_PARAM_TGT_RESET_TMO:
952		case ISCSI_PARAM_IFACE_NAME:
953		case ISCSI_PARAM_INITIATOR_NAME:
954		case ISCSI_PARAM_DISCOVERY_SESS:
955			return S_IRUGO;
956		default:
957			return 0;
958		}
959	}
960
961	return 0;
962}
963
964static struct scsi_host_template iscsi_iser_sht = {
965	.module                 = THIS_MODULE,
966	.name                   = "iSCSI Initiator over iSER",
967	.queuecommand           = iscsi_queuecommand,
968	.change_queue_depth	= scsi_change_queue_depth,
969	.sg_tablesize           = ISCSI_ISER_SG_TABLESIZE,
970	.max_sectors		= 1024,
971	.cmd_per_lun            = ISER_DEF_CMD_PER_LUN,
972	.eh_abort_handler       = iscsi_eh_abort,
973	.eh_device_reset_handler= iscsi_eh_device_reset,
974	.eh_target_reset_handler = iscsi_eh_recover_target,
975	.target_alloc		= iscsi_target_alloc,
976	.use_clustering         = DISABLE_CLUSTERING,
977	.proc_name              = "iscsi_iser",
978	.this_id                = -1,
979	.track_queue_depth	= 1,
980};
981
982static struct iscsi_transport iscsi_iser_transport = {
983	.owner                  = THIS_MODULE,
984	.name                   = "iser",
985	.caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_TEXT_NEGO,
986	/* session management */
987	.create_session         = iscsi_iser_session_create,
988	.destroy_session        = iscsi_iser_session_destroy,
989	/* connection management */
990	.create_conn            = iscsi_iser_conn_create,
991	.bind_conn              = iscsi_iser_conn_bind,
992	.destroy_conn           = iscsi_conn_teardown,
993	.attr_is_visible	= iser_attr_is_visible,
994	.set_param              = iscsi_iser_set_param,
995	.get_conn_param		= iscsi_conn_get_param,
996	.get_ep_param		= iscsi_iser_get_ep_param,
997	.get_session_param	= iscsi_session_get_param,
998	.start_conn             = iscsi_iser_conn_start,
999	.stop_conn              = iscsi_iser_conn_stop,
1000	/* iscsi host params */
1001	.get_host_param		= iscsi_host_get_param,
1002	.set_host_param		= iscsi_host_set_param,
1003	/* IO */
1004	.send_pdu		= iscsi_conn_send_pdu,
1005	.get_stats		= iscsi_iser_conn_get_stats,
1006	.init_task		= iscsi_iser_task_init,
1007	.xmit_task		= iscsi_iser_task_xmit,
1008	.cleanup_task		= iscsi_iser_cleanup_task,
1009	.alloc_pdu		= iscsi_iser_pdu_alloc,
1010	.check_protection	= iscsi_iser_check_protection,
1011	/* recovery */
1012	.session_recovery_timedout = iscsi_session_recovery_timedout,
1013
1014	.ep_connect             = iscsi_iser_ep_connect,
1015	.ep_poll                = iscsi_iser_ep_poll,
1016	.ep_disconnect          = iscsi_iser_ep_disconnect
1017};
1018
1019static int __init iser_init(void)
1020{
1021	int err;
1022
1023	iser_dbg("Starting iSER datamover...\n");
1024
1025	if (iscsi_max_lun < 1) {
1026		iser_err("Invalid max_lun value of %u\n", iscsi_max_lun);
1027		return -EINVAL;
1028	}
1029
1030	memset(&ig, 0, sizeof(struct iser_global));
1031
1032	ig.desc_cache = kmem_cache_create("iser_descriptors",
1033					  sizeof(struct iser_tx_desc),
1034					  0, SLAB_HWCACHE_ALIGN,
1035					  NULL);
1036	if (ig.desc_cache == NULL)
1037		return -ENOMEM;
1038
1039	/* device init is called only after the first addr resolution */
1040	mutex_init(&ig.device_list_mutex);
1041	INIT_LIST_HEAD(&ig.device_list);
1042	mutex_init(&ig.connlist_mutex);
1043	INIT_LIST_HEAD(&ig.connlist);
1044
1045	release_wq = alloc_workqueue("release workqueue", 0, 0);
1046	if (!release_wq) {
1047		iser_err("failed to allocate release workqueue\n");
1048		return -ENOMEM;
1049	}
1050
1051	iscsi_iser_scsi_transport = iscsi_register_transport(
1052							&iscsi_iser_transport);
1053	if (!iscsi_iser_scsi_transport) {
1054		iser_err("iscsi_register_transport failed\n");
1055		err = -EINVAL;
1056		goto register_transport_failure;
1057	}
1058
1059	return 0;
1060
1061register_transport_failure:
1062	kmem_cache_destroy(ig.desc_cache);
1063
1064	return err;
1065}
1066
1067static void __exit iser_exit(void)
1068{
1069	struct iser_conn *iser_conn, *n;
1070	int connlist_empty;
1071
1072	iser_dbg("Removing iSER datamover...\n");
1073	destroy_workqueue(release_wq);
1074
1075	mutex_lock(&ig.connlist_mutex);
1076	connlist_empty = list_empty(&ig.connlist);
1077	mutex_unlock(&ig.connlist_mutex);
1078
1079	if (!connlist_empty) {
1080		iser_err("Error cleanup stage completed but we still have iser "
1081			 "connections, destroying them anyway.\n");
1082		list_for_each_entry_safe(iser_conn, n, &ig.connlist,
1083					 conn_list) {
1084			iser_conn_release(iser_conn);
1085		}
1086	}
1087
1088	iscsi_unregister_transport(&iscsi_iser_transport);
1089	kmem_cache_destroy(ig.desc_cache);
1090}
1091
1092module_init(iser_init);
1093module_exit(iser_exit);
1094