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 <linux/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
77MODULE_DESCRIPTION("iSER (iSCSI Extensions for RDMA) Datamover");
78MODULE_LICENSE("Dual BSD/GPL");
79MODULE_AUTHOR("Alex Nezhinsky, Dan Bar Dov, Or Gerlitz");
80
81static struct scsi_host_template iscsi_iser_sht;
82static struct iscsi_transport iscsi_iser_transport;
83static struct scsi_transport_template *iscsi_iser_scsi_transport;
84static struct workqueue_struct *release_wq;
85static DEFINE_MUTEX(unbind_iser_conn_mutex);
86struct iser_global ig;
87
88int iser_debug_level = 0;
89module_param_named(debug_level, iser_debug_level, int, S_IRUGO | S_IWUSR);
90MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:disabled)");
91
92static unsigned int iscsi_max_lun = 512;
93module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
94MODULE_PARM_DESC(max_lun, "Max LUNs to allow per session (default:512");
95
96unsigned int iser_max_sectors = ISER_DEF_MAX_SECTORS;
97module_param_named(max_sectors, iser_max_sectors, uint, S_IRUGO | S_IWUSR);
98MODULE_PARM_DESC(max_sectors, "Max number of sectors in a single scsi command (default:1024");
99
100bool iser_always_reg = true;
101module_param_named(always_register, iser_always_reg, bool, S_IRUGO);
102MODULE_PARM_DESC(always_register,
103 "Always register memory, even for continuous memory regions (default:true)");
104
105bool iser_pi_enable = false;
106module_param_named(pi_enable, iser_pi_enable, bool, S_IRUGO);
107MODULE_PARM_DESC(pi_enable, "Enable T10-PI offload support (default:disabled)");
108
109int iser_pi_guard;
110module_param_named(pi_guard, iser_pi_guard, int, S_IRUGO);
111MODULE_PARM_DESC(pi_guard, "T10-PI guard_type [deprecated]");
112
113/*
114 * iscsi_iser_recv() - Process a successful recv completion
115 * @conn: iscsi connection
116 * @hdr: iscsi header
117 * @rx_data: buffer containing receive data payload
118 * @rx_data_len: length of rx_data
119 *
120 * Notes: In case of data length errors or iscsi PDU completion failures
121 * this routine will signal iscsi layer of connection failure.
122 */
123void
124iscsi_iser_recv(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
125 char *rx_data, int rx_data_len)
126{
127 int rc = 0;
128 int datalen;
129
130 /* verify PDU length */
131 datalen = ntoh24(hdr->dlength);
132 if (datalen > rx_data_len || (datalen + 4) < rx_data_len) {
133 iser_err("wrong datalen %d (hdr), %d (IB)\n",
134 datalen, rx_data_len);
135 rc = ISCSI_ERR_DATALEN;
136 goto error;
137 }
138
139 if (datalen != rx_data_len)
140 iser_dbg("aligned datalen (%d) hdr, %d (IB)\n",
141 datalen, rx_data_len);
142
143 rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
144 if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
145 goto error;
146
147 return;
148error:
149 iscsi_conn_failure(conn, rc);
150}
151
152/**
153 * iscsi_iser_pdu_alloc() - allocate an iscsi-iser PDU
154 * @task: iscsi task
155 * @opcode: iscsi command opcode
156 *
157 * Netes: This routine can't fail, just assign iscsi task
158 * hdr and max hdr size.
159 */
160static int
161iscsi_iser_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
162{
163 struct iscsi_iser_task *iser_task = task->dd_data;
164
165 task->hdr = (struct iscsi_hdr *)&iser_task->desc.iscsi_header;
166 task->hdr_max = sizeof(iser_task->desc.iscsi_header);
167
168 return 0;
169}
170
171/**
172 * iser_initialize_task_headers() - Initialize task headers
173 * @task: iscsi task
174 * @tx_desc: iser tx descriptor
175 *
176 * Notes:
177 * This routine may race with iser teardown flow for scsi
178 * error handling TMFs. So for TMF we should acquire the
179 * state mutex to avoid dereferencing the IB device which
180 * may have already been terminated.
181 */
182int
183iser_initialize_task_headers(struct iscsi_task *task,
184 struct iser_tx_desc *tx_desc)
185{
186 struct iser_conn *iser_conn = task->conn->dd_data;
187 struct iser_device *device = iser_conn->ib_conn.device;
188 struct iscsi_iser_task *iser_task = task->dd_data;
189 u64 dma_addr;
190 const bool mgmt_task = !task->sc && !in_interrupt();
191 int ret = 0;
192
193 if (unlikely(mgmt_task))
194 mutex_lock(&iser_conn->state_mutex);
195
196 if (unlikely(iser_conn->state != ISER_CONN_UP)) {
197 ret = -ENODEV;
198 goto out;
199 }
200
201 dma_addr = ib_dma_map_single(device->ib_device, (void *)tx_desc,
202 ISER_HEADERS_LEN, DMA_TO_DEVICE);
203 if (ib_dma_mapping_error(device->ib_device, dma_addr)) {
204 ret = -ENOMEM;
205 goto out;
206 }
207
208 tx_desc->wr_idx = 0;
209 tx_desc->mapped = true;
210 tx_desc->dma_addr = dma_addr;
211 tx_desc->tx_sg[0].addr = tx_desc->dma_addr;
212 tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;
213 tx_desc->tx_sg[0].lkey = device->pd->local_dma_lkey;
214
215 iser_task->iser_conn = iser_conn;
216out:
217 if (unlikely(mgmt_task))
218 mutex_unlock(&iser_conn->state_mutex);
219
220 return ret;
221}
222
223/**
224 * iscsi_iser_task_init() - Initialize iscsi-iser task
225 * @task: iscsi task
226 *
227 * Initialize the task for the scsi command or mgmt command.
228 *
229 * Return: Returns zero on success or -ENOMEM when failing
230 * to init task headers (dma mapping error).
231 */
232static int
233iscsi_iser_task_init(struct iscsi_task *task)
234{
235 struct iscsi_iser_task *iser_task = task->dd_data;
236 int ret;
237
238 ret = iser_initialize_task_headers(task, &iser_task->desc);
239 if (ret) {
240 iser_err("Failed to init task %p, err = %d\n",
241 iser_task, ret);
242 return ret;
243 }
244
245 /* mgmt task */
246 if (!task->sc)
247 return 0;
248
249 iser_task->command_sent = 0;
250 iser_task_rdma_init(iser_task);
251 iser_task->sc = task->sc;
252
253 return 0;
254}
255
256/**
257 * iscsi_iser_mtask_xmit() - xmit management (immediate) task
258 * @conn: iscsi connection
259 * @task: task management task
260 *
261 * Notes:
262 * The function can return -EAGAIN in which case caller must
263 * call it again later, or recover. '0' return code means successful
264 * xmit.
265 *
266 **/
267static int
268iscsi_iser_mtask_xmit(struct iscsi_conn *conn, struct iscsi_task *task)
269{
270 int error = 0;
271
272 iser_dbg("mtask xmit [cid %d itt 0x%x]\n", conn->id, task->itt);
273
274 error = iser_send_control(conn, task);
275
276 /* since iser xmits control with zero copy, tasks can not be recycled
277 * right after sending them.
278 * The recycling scheme is based on whether a response is expected
279 * - if yes, the task is recycled at iscsi_complete_pdu
280 * - if no, the task is recycled at iser_snd_completion
281 */
282 return error;
283}
284
285static int
286iscsi_iser_task_xmit_unsol_data(struct iscsi_conn *conn,
287 struct iscsi_task *task)
288{
289 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
290 struct iscsi_data hdr;
291 int error = 0;
292
293 /* Send data-out PDUs while there's still unsolicited data to send */
294 while (iscsi_task_has_unsol_data(task)) {
295 iscsi_prep_data_out_pdu(task, r2t, &hdr);
296 iser_dbg("Sending data-out: itt 0x%x, data count %d\n",
297 hdr.itt, r2t->data_count);
298
299 /* the buffer description has been passed with the command */
300 /* Send the command */
301 error = iser_send_data_out(conn, task, &hdr);
302 if (error) {
303 r2t->datasn--;
304 goto iscsi_iser_task_xmit_unsol_data_exit;
305 }
306 r2t->sent += r2t->data_count;
307 iser_dbg("Need to send %d more as data-out PDUs\n",
308 r2t->data_length - r2t->sent);
309 }
310
311iscsi_iser_task_xmit_unsol_data_exit:
312 return error;
313}
314
315/**
316 * iscsi_iser_task_xmit() - xmit iscsi-iser task
317 * @task: iscsi task
318 *
319 * Return: zero on success or escalates $error on failure.
320 */
321static int
322iscsi_iser_task_xmit(struct iscsi_task *task)
323{
324 struct iscsi_conn *conn = task->conn;
325 struct iscsi_iser_task *iser_task = task->dd_data;
326 int error = 0;
327
328 if (!task->sc)
329 return iscsi_iser_mtask_xmit(conn, task);
330
331 if (task->sc->sc_data_direction == DMA_TO_DEVICE) {
332 BUG_ON(scsi_bufflen(task->sc) == 0);
333
334 iser_dbg("cmd [itt %x total %d imm %d unsol_data %d\n",
335 task->itt, scsi_bufflen(task->sc),
336 task->imm_count, task->unsol_r2t.data_length);
337 }
338
339 iser_dbg("ctask xmit [cid %d itt 0x%x]\n",
340 conn->id, task->itt);
341
342 /* Send the cmd PDU */
343 if (!iser_task->command_sent) {
344 error = iser_send_command(conn, task);
345 if (error)
346 goto iscsi_iser_task_xmit_exit;
347 iser_task->command_sent = 1;
348 }
349
350 /* Send unsolicited data-out PDU(s) if necessary */
351 if (iscsi_task_has_unsol_data(task))
352 error = iscsi_iser_task_xmit_unsol_data(conn, task);
353
354 iscsi_iser_task_xmit_exit:
355 return error;
356}
357
358/**
359 * iscsi_iser_cleanup_task() - cleanup an iscsi-iser task
360 * @task: iscsi task
361 *
362 * Notes: In case the RDMA device is already NULL (might have
363 * been removed in DEVICE_REMOVAL CM event it will bail-out
364 * without doing dma unmapping.
365 */
366static void iscsi_iser_cleanup_task(struct iscsi_task *task)
367{
368 struct iscsi_iser_task *iser_task = task->dd_data;
369 struct iser_tx_desc *tx_desc = &iser_task->desc;
370 struct iser_conn *iser_conn = task->conn->dd_data;
371 struct iser_device *device = iser_conn->ib_conn.device;
372
373 /* DEVICE_REMOVAL event might have already released the device */
374 if (!device)
375 return;
376
377 if (likely(tx_desc->mapped)) {
378 ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
379 ISER_HEADERS_LEN, DMA_TO_DEVICE);
380 tx_desc->mapped = false;
381 }
382
383 /* mgmt tasks do not need special cleanup */
384 if (!task->sc)
385 return;
386
387 if (iser_task->status == ISER_TASK_STATUS_STARTED) {
388 iser_task->status = ISER_TASK_STATUS_COMPLETED;
389 iser_task_rdma_finalize(iser_task);
390 }
391}
392
393/**
394 * iscsi_iser_check_protection() - check protection information status of task.
395 * @task: iscsi task
396 * @sector: error sector if exsists (output)
397 *
398 * Return: zero if no data-integrity errors have occured
399 * 0x1: data-integrity error occured in the guard-block
400 * 0x2: data-integrity error occured in the reference tag
401 * 0x3: data-integrity error occured in the application tag
402 *
403 * In addition the error sector is marked.
404 */
405static u8
406iscsi_iser_check_protection(struct iscsi_task *task, sector_t *sector)
407{
408 struct iscsi_iser_task *iser_task = task->dd_data;
409
410 if (iser_task->dir[ISER_DIR_IN])
411 return iser_check_task_pi_status(iser_task, ISER_DIR_IN,
412 sector);
413 else
414 return iser_check_task_pi_status(iser_task, ISER_DIR_OUT,
415 sector);
416}
417
418/**
419 * iscsi_iser_conn_create() - create a new iscsi-iser connection
420 * @cls_session: iscsi class connection
421 * @conn_idx: connection index within the session (for MCS)
422 *
423 * Return: iscsi_cls_conn when iscsi_conn_setup succeeds or NULL
424 * otherwise.
425 */
426static struct iscsi_cls_conn *
427iscsi_iser_conn_create(struct iscsi_cls_session *cls_session,
428 uint32_t conn_idx)
429{
430 struct iscsi_conn *conn;
431 struct iscsi_cls_conn *cls_conn;
432
433 cls_conn = iscsi_conn_setup(cls_session, 0, conn_idx);
434 if (!cls_conn)
435 return NULL;
436 conn = cls_conn->dd_data;
437
438 /*
439 * due to issues with the login code re iser sematics
440 * this not set in iscsi_conn_setup - FIXME
441 */
442 conn->max_recv_dlength = ISER_RECV_DATA_SEG_LEN;
443
444 return cls_conn;
445}
446
447/**
448 * iscsi_iser_conn_bind() - bind iscsi and iser connection structures
449 * @cls_session: iscsi class session
450 * @cls_conn: iscsi class connection
451 * @transport_eph: transport end-point handle
452 * @is_leading: indicate if this is the session leading connection (MCS)
453 *
454 * Return: zero on success, $error if iscsi_conn_bind fails and
455 * -EINVAL in case end-point doesn't exsits anymore or iser connection
456 * state is not UP (teardown already started).
457 */
458static int
459iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
460 struct iscsi_cls_conn *cls_conn,
461 uint64_t transport_eph,
462 int is_leading)
463{
464 struct iscsi_conn *conn = cls_conn->dd_data;
465 struct iser_conn *iser_conn;
466 struct iscsi_endpoint *ep;
467 int error;
468
469 error = iscsi_conn_bind(cls_session, cls_conn, is_leading);
470 if (error)
471 return error;
472
473 /* the transport ep handle comes from user space so it must be
474 * verified against the global ib connections list */
475 ep = iscsi_lookup_endpoint(transport_eph);
476 if (!ep) {
477 iser_err("can't bind eph %llx\n",
478 (unsigned long long)transport_eph);
479 return -EINVAL;
480 }
481 iser_conn = ep->dd_data;
482
483 mutex_lock(&iser_conn->state_mutex);
484 if (iser_conn->state != ISER_CONN_UP) {
485 error = -EINVAL;
486 iser_err("iser_conn %p state is %d, teardown started\n",
487 iser_conn, iser_conn->state);
488 goto out;
489 }
490
491 error = iser_alloc_rx_descriptors(iser_conn, conn->session);
492 if (error)
493 goto out;
494
495 /* binds the iSER connection retrieved from the previously
496 * connected ep_handle to the iSCSI layer connection. exchanges
497 * connection pointers */
498 iser_info("binding iscsi conn %p to iser_conn %p\n", conn, iser_conn);
499
500 conn->dd_data = iser_conn;
501 iser_conn->iscsi_conn = conn;
502
503out:
504 mutex_unlock(&iser_conn->state_mutex);
505 return error;
506}
507
508/**
509 * iscsi_iser_conn_start() - start iscsi-iser connection
510 * @cls_conn: iscsi class connection
511 *
512 * Notes: Here iser intialize (or re-initialize) stop_completion as
513 * from this point iscsi must call conn_stop in session/connection
514 * teardown so iser transport must wait for it.
515 */
516static int
517iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn)
518{
519 struct iscsi_conn *iscsi_conn;
520 struct iser_conn *iser_conn;
521
522 iscsi_conn = cls_conn->dd_data;
523 iser_conn = iscsi_conn->dd_data;
524 reinit_completion(&iser_conn->stop_completion);
525
526 return iscsi_conn_start(cls_conn);
527}
528
529/**
530 * iscsi_iser_conn_stop() - stop iscsi-iser connection
531 * @cls_conn: iscsi class connection
532 * @flag: indicate if recover or terminate (passed as is)
533 *
534 * Notes: Calling iscsi_conn_stop might theoretically race with
535 * DEVICE_REMOVAL event and dereference a previously freed RDMA device
536 * handle, so we call it under iser the state lock to protect against
537 * this kind of race.
538 */
539static void
540iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
541{
542 struct iscsi_conn *conn = cls_conn->dd_data;
543 struct iser_conn *iser_conn = conn->dd_data;
544
545 iser_info("stopping iscsi_conn: %p, iser_conn: %p\n", conn, iser_conn);
546
547 /*
548 * Userspace may have goofed up and not bound the connection or
549 * might have only partially setup the connection.
550 */
551 if (iser_conn) {
552 mutex_lock(&iser_conn->state_mutex);
553 mutex_lock(&unbind_iser_conn_mutex);
554 iser_conn_terminate(iser_conn);
555 iscsi_conn_stop(cls_conn, flag);
556
557 /* unbind */
558 iser_conn->iscsi_conn = NULL;
559 conn->dd_data = NULL;
560 mutex_unlock(&unbind_iser_conn_mutex);
561
562 complete(&iser_conn->stop_completion);
563 mutex_unlock(&iser_conn->state_mutex);
564 } else {
565 iscsi_conn_stop(cls_conn, flag);
566 }
567}
568
569/**
570 * iscsi_iser_session_destroy() - destroy iscsi-iser session
571 * @cls_session: iscsi class session
572 *
573 * Removes and free iscsi host.
574 */
575static void
576iscsi_iser_session_destroy(struct iscsi_cls_session *cls_session)
577{
578 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
579
580 iscsi_session_teardown(cls_session);
581 iscsi_host_remove(shost);
582 iscsi_host_free(shost);
583}
584
585static inline unsigned int
586iser_dif_prot_caps(int prot_caps)
587{
588 return ((prot_caps & IB_PROT_T10DIF_TYPE_1) ?
589 SHOST_DIF_TYPE1_PROTECTION | SHOST_DIX_TYPE0_PROTECTION |
590 SHOST_DIX_TYPE1_PROTECTION : 0) |
591 ((prot_caps & IB_PROT_T10DIF_TYPE_2) ?
592 SHOST_DIF_TYPE2_PROTECTION | SHOST_DIX_TYPE2_PROTECTION : 0) |
593 ((prot_caps & IB_PROT_T10DIF_TYPE_3) ?
594 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE3_PROTECTION : 0);
595}
596
597/**
598 * iscsi_iser_session_create() - create an iscsi-iser session
599 * @ep: iscsi end-point handle
600 * @cmds_max: maximum commands in this session
601 * @qdepth: session command queue depth
602 * @initial_cmdsn: initiator command sequnce number
603 *
604 * Allocates and adds a scsi host, expose DIF supprot if
605 * exists, and sets up an iscsi session.
606 */
607static struct iscsi_cls_session *
608iscsi_iser_session_create(struct iscsi_endpoint *ep,
609 uint16_t cmds_max, uint16_t qdepth,
610 uint32_t initial_cmdsn)
611{
612 struct iscsi_cls_session *cls_session;
613 struct Scsi_Host *shost;
614 struct iser_conn *iser_conn = NULL;
615 struct ib_conn *ib_conn;
616 u32 max_fr_sectors;
617
618 shost = iscsi_host_alloc(&iscsi_iser_sht, 0, 0);
619 if (!shost)
620 return NULL;
621 shost->transportt = iscsi_iser_scsi_transport;
622 shost->cmd_per_lun = qdepth;
623 shost->max_lun = iscsi_max_lun;
624 shost->max_id = 0;
625 shost->max_channel = 0;
626 shost->max_cmd_len = 16;
627
628 /*
629 * older userspace tools (before 2.0-870) did not pass us
630 * the leading conn's ep so this will be NULL;
631 */
632 if (ep) {
633 iser_conn = ep->dd_data;
634 shost->sg_tablesize = iser_conn->scsi_sg_tablesize;
635 shost->can_queue = min_t(u16, cmds_max, iser_conn->max_cmds);
636
637 mutex_lock(&iser_conn->state_mutex);
638 if (iser_conn->state != ISER_CONN_UP) {
639 iser_err("iser conn %p already started teardown\n",
640 iser_conn);
641 mutex_unlock(&iser_conn->state_mutex);
642 goto free_host;
643 }
644
645 ib_conn = &iser_conn->ib_conn;
646 if (ib_conn->pi_support) {
647 u32 sig_caps = ib_conn->device->ib_device->attrs.sig_prot_cap;
648
649 scsi_host_set_prot(shost, iser_dif_prot_caps(sig_caps));
650 scsi_host_set_guard(shost, SHOST_DIX_GUARD_IP |
651 SHOST_DIX_GUARD_CRC);
652 }
653
654 if (iscsi_host_add(shost,
655 ib_conn->device->ib_device->dev.parent)) {
656 mutex_unlock(&iser_conn->state_mutex);
657 goto free_host;
658 }
659 mutex_unlock(&iser_conn->state_mutex);
660 } else {
661 shost->can_queue = min_t(u16, cmds_max, ISER_DEF_XMIT_CMDS_MAX);
662 if (iscsi_host_add(shost, NULL))
663 goto free_host;
664 }
665
666 max_fr_sectors = (shost->sg_tablesize * PAGE_SIZE) >> 9;
667 shost->max_sectors = min(iser_max_sectors, max_fr_sectors);
668
669 iser_dbg("iser_conn %p, sg_tablesize %u, max_sectors %u\n",
670 iser_conn, shost->sg_tablesize,
671 shost->max_sectors);
672
673 if (shost->max_sectors < iser_max_sectors)
674 iser_warn("max_sectors was reduced from %u to %u\n",
675 iser_max_sectors, shost->max_sectors);
676
677 cls_session = iscsi_session_setup(&iscsi_iser_transport, shost,
678 shost->can_queue, 0,
679 sizeof(struct iscsi_iser_task),
680 initial_cmdsn, 0);
681 if (!cls_session)
682 goto remove_host;
683
684 return cls_session;
685
686remove_host:
687 iscsi_host_remove(shost);
688free_host:
689 iscsi_host_free(shost);
690 return NULL;
691}
692
693static int
694iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,
695 enum iscsi_param param, char *buf, int buflen)
696{
697 int value;
698
699 switch (param) {
700 case ISCSI_PARAM_MAX_RECV_DLENGTH:
701 /* TBD */
702 break;
703 case ISCSI_PARAM_HDRDGST_EN:
704 sscanf(buf, "%d", &value);
705 if (value) {
706 iser_err("DataDigest wasn't negotiated to None\n");
707 return -EPROTO;
708 }
709 break;
710 case ISCSI_PARAM_DATADGST_EN:
711 sscanf(buf, "%d", &value);
712 if (value) {
713 iser_err("DataDigest wasn't negotiated to None\n");
714 return -EPROTO;
715 }
716 break;
717 case ISCSI_PARAM_IFMARKER_EN:
718 sscanf(buf, "%d", &value);
719 if (value) {
720 iser_err("IFMarker wasn't negotiated to No\n");
721 return -EPROTO;
722 }
723 break;
724 case ISCSI_PARAM_OFMARKER_EN:
725 sscanf(buf, "%d", &value);
726 if (value) {
727 iser_err("OFMarker wasn't negotiated to No\n");
728 return -EPROTO;
729 }
730 break;
731 default:
732 return iscsi_set_param(cls_conn, param, buf, buflen);
733 }
734
735 return 0;
736}
737
738/**
739 * iscsi_iser_set_param() - set class connection parameter
740 * @cls_conn: iscsi class connection
741 * @stats: iscsi stats to output
742 *
743 * Output connection statistics.
744 */
745static void
746iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
747{
748 struct iscsi_conn *conn = cls_conn->dd_data;
749
750 stats->txdata_octets = conn->txdata_octets;
751 stats->rxdata_octets = conn->rxdata_octets;
752 stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
753 stats->dataout_pdus = conn->dataout_pdus_cnt;
754 stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
755 stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */
756 stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
757 stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
758 stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
759 stats->custom_length = 0;
760}
761
762static int iscsi_iser_get_ep_param(struct iscsi_endpoint *ep,
763 enum iscsi_param param, char *buf)
764{
765 struct iser_conn *iser_conn = ep->dd_data;
766 int len;
767
768 switch (param) {
769 case ISCSI_PARAM_CONN_PORT:
770 case ISCSI_PARAM_CONN_ADDRESS:
771 if (!iser_conn || !iser_conn->ib_conn.cma_id)
772 return -ENOTCONN;
773
774 return iscsi_conn_get_addr_param((struct sockaddr_storage *)
775 &iser_conn->ib_conn.cma_id->route.addr.dst_addr,
776 param, buf);
777 break;
778 default:
779 return -ENOSYS;
780 }
781
782 return len;
783}
784
785/**
786 * iscsi_iser_ep_connect() - Initiate iSER connection establishment
787 * @shost: scsi_host
788 * @dst_addr: destination address
789 * @non-blocking: indicate if routine can block
790 *
791 * Allocate an iscsi endpoint, an iser_conn structure and bind them.
792 * After that start RDMA connection establishment via rdma_cm. We
793 * don't allocate iser_conn embedded in iscsi_endpoint since in teardown
794 * the endpoint will be destroyed at ep_disconnect while iser_conn will
795 * cleanup its resources asynchronuously.
796 *
797 * Return: iscsi_endpoint created by iscsi layer or ERR_PTR(error)
798 * if fails.
799 */
800static struct iscsi_endpoint *
801iscsi_iser_ep_connect(struct Scsi_Host *shost, struct sockaddr *dst_addr,
802 int non_blocking)
803{
804 int err;
805 struct iser_conn *iser_conn;
806 struct iscsi_endpoint *ep;
807
808 ep = iscsi_create_endpoint(0);
809 if (!ep)
810 return ERR_PTR(-ENOMEM);
811
812 iser_conn = kzalloc(sizeof(*iser_conn), GFP_KERNEL);
813 if (!iser_conn) {
814 err = -ENOMEM;
815 goto failure;
816 }
817
818 ep->dd_data = iser_conn;
819 iser_conn->ep = ep;
820 iser_conn_init(iser_conn);
821
822 err = iser_connect(iser_conn, NULL, dst_addr, non_blocking);
823 if (err)
824 goto failure;
825
826 return ep;
827failure:
828 iscsi_destroy_endpoint(ep);
829 return ERR_PTR(err);
830}
831
832/**
833 * iscsi_iser_ep_poll() - poll for iser connection establishment to complete
834 * @ep: iscsi endpoint (created at ep_connect)
835 * @timeout_ms: polling timeout allowed in ms.
836 *
837 * This routine boils down to waiting for up_completion signaling
838 * that cma_id got CONNECTED event.
839 *
840 * Return: 1 if succeeded in connection establishment, 0 if timeout expired
841 * (libiscsi will retry will kick in) or -1 if interrupted by signal
842 * or more likely iser connection state transitioned to TEMINATING or
843 * DOWN during the wait period.
844 */
845static int
846iscsi_iser_ep_poll(struct iscsi_endpoint *ep, int timeout_ms)
847{
848 struct iser_conn *iser_conn = ep->dd_data;
849 int rc;
850
851 rc = wait_for_completion_interruptible_timeout(&iser_conn->up_completion,
852 msecs_to_jiffies(timeout_ms));
853 /* if conn establishment failed, return error code to iscsi */
854 if (rc == 0) {
855 mutex_lock(&iser_conn->state_mutex);
856 if (iser_conn->state == ISER_CONN_TERMINATING ||
857 iser_conn->state == ISER_CONN_DOWN)
858 rc = -1;
859 mutex_unlock(&iser_conn->state_mutex);
860 }
861
862 iser_info("iser conn %p rc = %d\n", iser_conn, rc);
863
864 if (rc > 0)
865 return 1; /* success, this is the equivalent of EPOLLOUT */
866 else if (!rc)
867 return 0; /* timeout */
868 else
869 return rc; /* signal */
870}
871
872/**
873 * iscsi_iser_ep_disconnect() - Initiate connection teardown process
874 * @ep: iscsi endpoint handle
875 *
876 * This routine is not blocked by iser and RDMA termination process
877 * completion as we queue a deffered work for iser/RDMA destruction
878 * and cleanup or actually call it immediately in case we didn't pass
879 * iscsi conn bind/start stage, thus it is safe.
880 */
881static void
882iscsi_iser_ep_disconnect(struct iscsi_endpoint *ep)
883{
884 struct iser_conn *iser_conn = ep->dd_data;
885
886 iser_info("ep %p iser conn %p\n", ep, iser_conn);
887
888 mutex_lock(&iser_conn->state_mutex);
889 iser_conn_terminate(iser_conn);
890
891 /*
892 * if iser_conn and iscsi_conn are bound, we must wait for
893 * iscsi_conn_stop and flush errors completion before freeing
894 * the iser resources. Otherwise we are safe to free resources
895 * immediately.
896 */
897 if (iser_conn->iscsi_conn) {
898 INIT_WORK(&iser_conn->release_work, iser_release_work);
899 queue_work(release_wq, &iser_conn->release_work);
900 mutex_unlock(&iser_conn->state_mutex);
901 } else {
902 iser_conn->state = ISER_CONN_DOWN;
903 mutex_unlock(&iser_conn->state_mutex);
904 iser_conn_release(iser_conn);
905 }
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 int iscsi_iser_slave_alloc(struct scsi_device *sdev)
965{
966 struct iscsi_session *session;
967 struct iser_conn *iser_conn;
968 struct ib_device *ib_dev;
969
970 mutex_lock(&unbind_iser_conn_mutex);
971
972 session = starget_to_session(scsi_target(sdev))->dd_data;
973 iser_conn = session->leadconn->dd_data;
974 if (!iser_conn) {
975 mutex_unlock(&unbind_iser_conn_mutex);
976 return -ENOTCONN;
977 }
978 ib_dev = iser_conn->ib_conn.device->ib_device;
979
980 if (!(ib_dev->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG))
981 blk_queue_virt_boundary(sdev->request_queue, ~MASK_4K);
982
983 mutex_unlock(&unbind_iser_conn_mutex);
984
985 return 0;
986}
987
988static struct scsi_host_template iscsi_iser_sht = {
989 .module = THIS_MODULE,
990 .name = "iSCSI Initiator over iSER",
991 .queuecommand = iscsi_queuecommand,
992 .change_queue_depth = scsi_change_queue_depth,
993 .sg_tablesize = ISCSI_ISER_DEF_SG_TABLESIZE,
994 .cmd_per_lun = ISER_DEF_CMD_PER_LUN,
995 .eh_timed_out = iscsi_eh_cmd_timed_out,
996 .eh_abort_handler = iscsi_eh_abort,
997 .eh_device_reset_handler= iscsi_eh_device_reset,
998 .eh_target_reset_handler = iscsi_eh_recover_target,
999 .target_alloc = iscsi_target_alloc,
1000 .slave_alloc = iscsi_iser_slave_alloc,
1001 .proc_name = "iscsi_iser",
1002 .this_id = -1,
1003 .track_queue_depth = 1,
1004};
1005
1006static struct iscsi_transport iscsi_iser_transport = {
1007 .owner = THIS_MODULE,
1008 .name = "iser",
1009 .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_TEXT_NEGO,
1010 /* session management */
1011 .create_session = iscsi_iser_session_create,
1012 .destroy_session = iscsi_iser_session_destroy,
1013 /* connection management */
1014 .create_conn = iscsi_iser_conn_create,
1015 .bind_conn = iscsi_iser_conn_bind,
1016 .destroy_conn = iscsi_conn_teardown,
1017 .attr_is_visible = iser_attr_is_visible,
1018 .set_param = iscsi_iser_set_param,
1019 .get_conn_param = iscsi_conn_get_param,
1020 .get_ep_param = iscsi_iser_get_ep_param,
1021 .get_session_param = iscsi_session_get_param,
1022 .start_conn = iscsi_iser_conn_start,
1023 .stop_conn = iscsi_iser_conn_stop,
1024 /* iscsi host params */
1025 .get_host_param = iscsi_host_get_param,
1026 .set_host_param = iscsi_host_set_param,
1027 /* IO */
1028 .send_pdu = iscsi_conn_send_pdu,
1029 .get_stats = iscsi_iser_conn_get_stats,
1030 .init_task = iscsi_iser_task_init,
1031 .xmit_task = iscsi_iser_task_xmit,
1032 .cleanup_task = iscsi_iser_cleanup_task,
1033 .alloc_pdu = iscsi_iser_pdu_alloc,
1034 .check_protection = iscsi_iser_check_protection,
1035 /* recovery */
1036 .session_recovery_timedout = iscsi_session_recovery_timedout,
1037
1038 .ep_connect = iscsi_iser_ep_connect,
1039 .ep_poll = iscsi_iser_ep_poll,
1040 .ep_disconnect = iscsi_iser_ep_disconnect
1041};
1042
1043static int __init iser_init(void)
1044{
1045 int err;
1046
1047 iser_dbg("Starting iSER datamover...\n");
1048
1049 if (iscsi_max_lun < 1) {
1050 iser_err("Invalid max_lun value of %u\n", iscsi_max_lun);
1051 return -EINVAL;
1052 }
1053
1054 memset(&ig, 0, sizeof(struct iser_global));
1055
1056 ig.desc_cache = kmem_cache_create("iser_descriptors",
1057 sizeof(struct iser_tx_desc),
1058 0, SLAB_HWCACHE_ALIGN,
1059 NULL);
1060 if (ig.desc_cache == NULL)
1061 return -ENOMEM;
1062
1063 /* device init is called only after the first addr resolution */
1064 mutex_init(&ig.device_list_mutex);
1065 INIT_LIST_HEAD(&ig.device_list);
1066 mutex_init(&ig.connlist_mutex);
1067 INIT_LIST_HEAD(&ig.connlist);
1068
1069 release_wq = alloc_workqueue("release workqueue", 0, 0);
1070 if (!release_wq) {
1071 iser_err("failed to allocate release workqueue\n");
1072 err = -ENOMEM;
1073 goto err_alloc_wq;
1074 }
1075
1076 iscsi_iser_scsi_transport = iscsi_register_transport(
1077 &iscsi_iser_transport);
1078 if (!iscsi_iser_scsi_transport) {
1079 iser_err("iscsi_register_transport failed\n");
1080 err = -EINVAL;
1081 goto err_reg;
1082 }
1083
1084 return 0;
1085
1086err_reg:
1087 destroy_workqueue(release_wq);
1088err_alloc_wq:
1089 kmem_cache_destroy(ig.desc_cache);
1090
1091 return err;
1092}
1093
1094static void __exit iser_exit(void)
1095{
1096 struct iser_conn *iser_conn, *n;
1097 int connlist_empty;
1098
1099 iser_dbg("Removing iSER datamover...\n");
1100 destroy_workqueue(release_wq);
1101
1102 mutex_lock(&ig.connlist_mutex);
1103 connlist_empty = list_empty(&ig.connlist);
1104 mutex_unlock(&ig.connlist_mutex);
1105
1106 if (!connlist_empty) {
1107 iser_err("Error cleanup stage completed but we still have iser "
1108 "connections, destroying them anyway\n");
1109 list_for_each_entry_safe(iser_conn, n, &ig.connlist,
1110 conn_list) {
1111 iser_conn_release(iser_conn);
1112 }
1113 }
1114
1115 iscsi_unregister_transport(&iscsi_iser_transport);
1116 kmem_cache_destroy(ig.desc_cache);
1117}
1118
1119module_init(iser_init);
1120module_exit(iser_exit);
1121