[go: nahoru, domu]

1/*
2 * Xen SCSI backend driver
3 *
4 * Copyright (c) 2008, FUJITSU Limited
5 *
6 * Based on the blkback driver code.
7 * Adaption to kernel taget core infrastructure taken from vhost/scsi.c
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation; or, when distributed
12 * separately from the Linux kernel or incorporated into other
13 * software packages, subject to the following license:
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining a copy
16 * of this source file (the "Software"), to deal in the Software without
17 * restriction, including without limitation the rights to use, copy, modify,
18 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
19 * and to permit persons to whom the Software is furnished to do so, subject to
20 * the following conditions:
21 *
22 * The above copyright notice and this permission notice shall be included in
23 * all copies or substantial portions of the Software.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
31 * IN THE SOFTWARE.
32 */
33
34#include <stdarg.h>
35
36#include <linux/module.h>
37#include <linux/utsname.h>
38#include <linux/interrupt.h>
39#include <linux/slab.h>
40#include <linux/wait.h>
41#include <linux/sched.h>
42#include <linux/list.h>
43#include <linux/gfp.h>
44#include <linux/delay.h>
45#include <linux/spinlock.h>
46#include <linux/configfs.h>
47
48#include <generated/utsrelease.h>
49
50#include <scsi/scsi_dbg.h>
51#include <scsi/scsi_eh.h>
52#include <scsi/scsi_tcq.h>
53
54#include <target/target_core_base.h>
55#include <target/target_core_fabric.h>
56#include <target/target_core_configfs.h>
57#include <target/target_core_fabric_configfs.h>
58
59#include <asm/hypervisor.h>
60
61#include <xen/xen.h>
62#include <xen/balloon.h>
63#include <xen/events.h>
64#include <xen/xenbus.h>
65#include <xen/grant_table.h>
66#include <xen/page.h>
67
68#include <xen/interface/grant_table.h>
69#include <xen/interface/io/vscsiif.h>
70
71#define DPRINTK(_f, _a...)			\
72	pr_debug("(file=%s, line=%d) " _f, __FILE__ , __LINE__ , ## _a)
73
74#define VSCSI_VERSION	"v0.1"
75#define VSCSI_NAMELEN	32
76
77struct ids_tuple {
78	unsigned int hst;		/* host    */
79	unsigned int chn;		/* channel */
80	unsigned int tgt;		/* target  */
81	unsigned int lun;		/* LUN     */
82};
83
84struct v2p_entry {
85	struct ids_tuple v;		/* translate from */
86	struct scsiback_tpg *tpg;	/* translate to   */
87	unsigned int lun;
88	struct kref kref;
89	struct list_head l;
90};
91
92struct vscsibk_info {
93	struct xenbus_device *dev;
94
95	domid_t domid;
96	unsigned int irq;
97
98	struct vscsiif_back_ring ring;
99	int ring_error;
100
101	spinlock_t ring_lock;
102	atomic_t nr_unreplied_reqs;
103
104	spinlock_t v2p_lock;
105	struct list_head v2p_entry_lists;
106
107	wait_queue_head_t waiting_to_free;
108};
109
110/* theoretical maximum of grants for one request */
111#define VSCSI_MAX_GRANTS	(SG_ALL + VSCSIIF_SG_TABLESIZE)
112
113/*
114 * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
115 * call to map/unmap grants. Don't choose it too large, as there are arrays
116 * with VSCSI_GRANT_BATCH elements allocated on the stack.
117 */
118#define VSCSI_GRANT_BATCH	16
119
120struct vscsibk_pend {
121	uint16_t rqid;
122
123	uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
124	uint8_t cmd_len;
125
126	uint8_t sc_data_direction;
127	uint16_t n_sg;		/* real length of SG list */
128	uint16_t n_grants;	/* SG pages and potentially SG list */
129	uint32_t data_len;
130	uint32_t result;
131
132	struct vscsibk_info *info;
133	struct v2p_entry *v2p;
134	struct scatterlist *sgl;
135
136	uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
137
138	grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
139	struct page *pages[VSCSI_MAX_GRANTS];
140
141	struct se_cmd se_cmd;
142};
143
144struct scsiback_tmr {
145	atomic_t tmr_complete;
146	wait_queue_head_t tmr_wait;
147};
148
149struct scsiback_nexus {
150	/* Pointer to TCM session for I_T Nexus */
151	struct se_session *tvn_se_sess;
152};
153
154struct scsiback_tport {
155	/* SCSI protocol the tport is providing */
156	u8 tport_proto_id;
157	/* Binary World Wide unique Port Name for pvscsi Target port */
158	u64 tport_wwpn;
159	/* ASCII formatted WWPN for pvscsi Target port */
160	char tport_name[VSCSI_NAMELEN];
161	/* Returned by scsiback_make_tport() */
162	struct se_wwn tport_wwn;
163};
164
165struct scsiback_tpg {
166	/* scsiback port target portal group tag for TCM */
167	u16 tport_tpgt;
168	/* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
169	int tv_tpg_port_count;
170	/* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
171	int tv_tpg_fe_count;
172	/* list for scsiback_list */
173	struct list_head tv_tpg_list;
174	/* Used to protect access for tpg_nexus */
175	struct mutex tv_tpg_mutex;
176	/* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
177	struct scsiback_nexus *tpg_nexus;
178	/* Pointer back to scsiback_tport */
179	struct scsiback_tport *tport;
180	/* Returned by scsiback_make_tpg() */
181	struct se_portal_group se_tpg;
182	/* alias used in xenstore */
183	char param_alias[VSCSI_NAMELEN];
184	/* list of info structures related to this target portal group */
185	struct list_head info_list;
186};
187
188#define SCSIBACK_INVALID_HANDLE (~0)
189
190static bool log_print_stat;
191module_param(log_print_stat, bool, 0644);
192
193static int scsiback_max_buffer_pages = 1024;
194module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
195MODULE_PARM_DESC(max_buffer_pages,
196"Maximum number of free pages to keep in backend buffer");
197
198static struct kmem_cache *scsiback_cachep;
199static DEFINE_SPINLOCK(free_pages_lock);
200static int free_pages_num;
201static LIST_HEAD(scsiback_free_pages);
202
203/* Global spinlock to protect scsiback TPG list */
204static DEFINE_MUTEX(scsiback_mutex);
205static LIST_HEAD(scsiback_list);
206
207/* Local pointer to allocated TCM configfs fabric module */
208static struct target_fabric_configfs *scsiback_fabric_configfs;
209
210static void scsiback_get(struct vscsibk_info *info)
211{
212	atomic_inc(&info->nr_unreplied_reqs);
213}
214
215static void scsiback_put(struct vscsibk_info *info)
216{
217	if (atomic_dec_and_test(&info->nr_unreplied_reqs))
218		wake_up(&info->waiting_to_free);
219}
220
221static void put_free_pages(struct page **page, int num)
222{
223	unsigned long flags;
224	int i = free_pages_num + num, n = num;
225
226	if (num == 0)
227		return;
228	if (i > scsiback_max_buffer_pages) {
229		n = min(num, i - scsiback_max_buffer_pages);
230		free_xenballooned_pages(n, page + num - n);
231		n = num - n;
232	}
233	spin_lock_irqsave(&free_pages_lock, flags);
234	for (i = 0; i < n; i++)
235		list_add(&page[i]->lru, &scsiback_free_pages);
236	free_pages_num += n;
237	spin_unlock_irqrestore(&free_pages_lock, flags);
238}
239
240static int get_free_page(struct page **page)
241{
242	unsigned long flags;
243
244	spin_lock_irqsave(&free_pages_lock, flags);
245	if (list_empty(&scsiback_free_pages)) {
246		spin_unlock_irqrestore(&free_pages_lock, flags);
247		return alloc_xenballooned_pages(1, page, false);
248	}
249	page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
250	list_del(&page[0]->lru);
251	free_pages_num--;
252	spin_unlock_irqrestore(&free_pages_lock, flags);
253	return 0;
254}
255
256static unsigned long vaddr_page(struct page *page)
257{
258	unsigned long pfn = page_to_pfn(page);
259
260	return (unsigned long)pfn_to_kaddr(pfn);
261}
262
263static unsigned long vaddr(struct vscsibk_pend *req, int seg)
264{
265	return vaddr_page(req->pages[seg]);
266}
267
268static void scsiback_print_status(char *sense_buffer, int errors,
269					struct vscsibk_pend *pending_req)
270{
271	struct scsiback_tpg *tpg = pending_req->v2p->tpg;
272
273	pr_err("xen-pvscsi[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n",
274	       tpg->tport->tport_name, pending_req->v2p->lun,
275	       pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
276	       host_byte(errors), driver_byte(errors));
277
278	if (CHECK_CONDITION & status_byte(errors))
279		__scsi_print_sense("xen-pvscsi", sense_buffer,
280				   SCSI_SENSE_BUFFERSIZE);
281}
282
283static void scsiback_fast_flush_area(struct vscsibk_pend *req)
284{
285	struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
286	struct page *pages[VSCSI_GRANT_BATCH];
287	unsigned int i, invcount = 0;
288	grant_handle_t handle;
289	int err;
290
291	kfree(req->sgl);
292	req->sgl = NULL;
293	req->n_sg = 0;
294
295	if (!req->n_grants)
296		return;
297
298	for (i = 0; i < req->n_grants; i++) {
299		handle = req->grant_handles[i];
300		if (handle == SCSIBACK_INVALID_HANDLE)
301			continue;
302		gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
303				    GNTMAP_host_map, handle);
304		req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
305		pages[invcount] = req->pages[i];
306		put_page(pages[invcount]);
307		invcount++;
308		if (invcount < VSCSI_GRANT_BATCH)
309			continue;
310		err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
311		BUG_ON(err);
312		invcount = 0;
313	}
314
315	if (invcount) {
316		err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
317		BUG_ON(err);
318	}
319
320	put_free_pages(req->pages, req->n_grants);
321	req->n_grants = 0;
322}
323
324static void scsiback_free_translation_entry(struct kref *kref)
325{
326	struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
327	struct scsiback_tpg *tpg = entry->tpg;
328
329	mutex_lock(&tpg->tv_tpg_mutex);
330	tpg->tv_tpg_fe_count--;
331	mutex_unlock(&tpg->tv_tpg_mutex);
332
333	kfree(entry);
334}
335
336static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
337			uint32_t resid, struct vscsibk_pend *pending_req)
338{
339	struct vscsiif_response *ring_res;
340	struct vscsibk_info *info = pending_req->info;
341	int notify;
342	struct scsi_sense_hdr sshdr;
343	unsigned long flags;
344	unsigned len;
345
346	spin_lock_irqsave(&info->ring_lock, flags);
347
348	ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
349	info->ring.rsp_prod_pvt++;
350
351	ring_res->rslt   = result;
352	ring_res->rqid   = pending_req->rqid;
353
354	if (sense_buffer != NULL &&
355	    scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
356				 &sshdr)) {
357		len = min_t(unsigned, 8 + sense_buffer[7],
358			    VSCSIIF_SENSE_BUFFERSIZE);
359		memcpy(ring_res->sense_buffer, sense_buffer, len);
360		ring_res->sense_len = len;
361	} else {
362		ring_res->sense_len = 0;
363	}
364
365	ring_res->residual_len = resid;
366
367	RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
368	spin_unlock_irqrestore(&info->ring_lock, flags);
369
370	if (notify)
371		notify_remote_via_irq(info->irq);
372
373	if (pending_req->v2p)
374		kref_put(&pending_req->v2p->kref,
375			 scsiback_free_translation_entry);
376}
377
378static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
379{
380	struct vscsibk_info *info = pending_req->info;
381	unsigned char *sense_buffer;
382	unsigned int resid;
383	int errors;
384
385	sense_buffer = pending_req->sense_buffer;
386	resid        = pending_req->se_cmd.residual_count;
387	errors       = pending_req->result;
388
389	if (errors && log_print_stat)
390		scsiback_print_status(sense_buffer, errors, pending_req);
391
392	scsiback_fast_flush_area(pending_req);
393	scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
394	scsiback_put(info);
395}
396
397static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
398{
399	struct se_cmd *se_cmd = &pending_req->se_cmd;
400	struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
401	int rc;
402
403	memset(pending_req->sense_buffer, 0, VSCSIIF_SENSE_BUFFERSIZE);
404
405	memset(se_cmd, 0, sizeof(*se_cmd));
406
407	scsiback_get(pending_req->info);
408	rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
409			pending_req->sense_buffer, pending_req->v2p->lun,
410			pending_req->data_len, 0,
411			pending_req->sc_data_direction, 0,
412			pending_req->sgl, pending_req->n_sg,
413			NULL, 0, NULL, 0);
414	if (rc < 0) {
415		transport_send_check_condition_and_sense(se_cmd,
416				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
417		transport_generic_free_cmd(se_cmd, 0);
418	}
419}
420
421static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
422	struct page **pg, grant_handle_t *grant, int cnt)
423{
424	int err, i;
425
426	if (!cnt)
427		return 0;
428
429	err = gnttab_map_refs(map, NULL, pg, cnt);
430	BUG_ON(err);
431	for (i = 0; i < cnt; i++) {
432		if (unlikely(map[i].status != GNTST_okay)) {
433			pr_err("xen-pvscsi: invalid buffer -- could not remap it\n");
434			map[i].handle = SCSIBACK_INVALID_HANDLE;
435			err = -ENOMEM;
436		} else {
437			get_page(pg[i]);
438		}
439		grant[i] = map[i].handle;
440	}
441	return err;
442}
443
444static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
445			struct scsiif_request_segment *seg, struct page **pg,
446			grant_handle_t *grant, int cnt, u32 flags)
447{
448	int mapcount = 0, i, err = 0;
449	struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
450	struct vscsibk_info *info = pending_req->info;
451
452	for (i = 0; i < cnt; i++) {
453		if (get_free_page(pg + mapcount)) {
454			put_free_pages(pg, mapcount);
455			pr_err("xen-pvscsi: no grant page\n");
456			return -ENOMEM;
457		}
458		gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
459				  flags, seg[i].gref, info->domid);
460		mapcount++;
461		if (mapcount < VSCSI_GRANT_BATCH)
462			continue;
463		err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
464		pg += mapcount;
465		grant += mapcount;
466		pending_req->n_grants += mapcount;
467		if (err)
468			return err;
469		mapcount = 0;
470	}
471	err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
472	pending_req->n_grants += mapcount;
473	return err;
474}
475
476static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
477					struct vscsibk_pend *pending_req)
478{
479	u32 flags;
480	int i, err, n_segs, i_seg = 0;
481	struct page **pg;
482	struct scsiif_request_segment *seg;
483	unsigned long end_seg = 0;
484	unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
485	unsigned int nr_sgl = 0;
486	struct scatterlist *sg;
487	grant_handle_t *grant;
488
489	pending_req->n_sg = 0;
490	pending_req->n_grants = 0;
491	pending_req->data_len = 0;
492
493	nr_segments &= ~VSCSIIF_SG_GRANT;
494	if (!nr_segments)
495		return 0;
496
497	if (nr_segments > VSCSIIF_SG_TABLESIZE) {
498		DPRINTK("xen-pvscsi: invalid parameter nr_seg = %d\n",
499			ring_req->nr_segments);
500		return -EINVAL;
501	}
502
503	if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
504		err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
505			pending_req->pages, pending_req->grant_handles,
506			nr_segments, GNTMAP_host_map | GNTMAP_readonly);
507		if (err)
508			return err;
509		nr_sgl = nr_segments;
510		nr_segments = 0;
511		for (i = 0; i < nr_sgl; i++) {
512			n_segs = ring_req->seg[i].length /
513				 sizeof(struct scsiif_request_segment);
514			if ((unsigned)ring_req->seg[i].offset +
515			    (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
516			    n_segs * sizeof(struct scsiif_request_segment) !=
517			    ring_req->seg[i].length)
518				return -EINVAL;
519			nr_segments += n_segs;
520		}
521		if (nr_segments > SG_ALL) {
522			DPRINTK("xen-pvscsi: invalid nr_seg = %d\n",
523				nr_segments);
524			return -EINVAL;
525		}
526	}
527
528	/* free of (sgl) in fast_flush_area()*/
529	pending_req->sgl = kmalloc_array(nr_segments,
530					sizeof(struct scatterlist), GFP_KERNEL);
531	if (!pending_req->sgl)
532		return -ENOMEM;
533
534	sg_init_table(pending_req->sgl, nr_segments);
535	pending_req->n_sg = nr_segments;
536
537	flags = GNTMAP_host_map;
538	if (pending_req->sc_data_direction == DMA_TO_DEVICE)
539		flags |= GNTMAP_readonly;
540
541	pg = pending_req->pages + nr_sgl;
542	grant = pending_req->grant_handles + nr_sgl;
543	if (!nr_sgl) {
544		seg = ring_req->seg;
545		err = scsiback_gnttab_data_map_list(pending_req, seg,
546			pg, grant, nr_segments, flags);
547		if (err)
548			return err;
549	} else {
550		for (i = 0; i < nr_sgl; i++) {
551			seg = (struct scsiif_request_segment *)(
552			      vaddr(pending_req, i) + ring_req->seg[i].offset);
553			n_segs = ring_req->seg[i].length /
554				 sizeof(struct scsiif_request_segment);
555			err = scsiback_gnttab_data_map_list(pending_req, seg,
556				pg, grant, n_segs, flags);
557			if (err)
558				return err;
559			pg += n_segs;
560			grant += n_segs;
561		}
562		end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
563		seg = (struct scsiif_request_segment *)end_seg;
564		end_seg += ring_req->seg[0].length;
565		pg = pending_req->pages + nr_sgl;
566	}
567
568	for_each_sg(pending_req->sgl, sg, nr_segments, i) {
569		sg_set_page(sg, pg[i], seg->length, seg->offset);
570		pending_req->data_len += seg->length;
571		seg++;
572		if (nr_sgl && (unsigned long)seg >= end_seg) {
573			i_seg++;
574			end_seg = vaddr(pending_req, i_seg) +
575				  ring_req->seg[i_seg].offset;
576			seg = (struct scsiif_request_segment *)end_seg;
577			end_seg += ring_req->seg[i_seg].length;
578		}
579		if (sg->offset >= PAGE_SIZE ||
580		    sg->length > PAGE_SIZE ||
581		    sg->offset + sg->length > PAGE_SIZE)
582			return -EINVAL;
583	}
584
585	return 0;
586}
587
588static void scsiback_disconnect(struct vscsibk_info *info)
589{
590	wait_event(info->waiting_to_free,
591		atomic_read(&info->nr_unreplied_reqs) == 0);
592
593	unbind_from_irqhandler(info->irq, info);
594	info->irq = 0;
595	xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
596}
597
598static void scsiback_device_action(struct vscsibk_pend *pending_req,
599	enum tcm_tmreq_table act, int tag)
600{
601	int rc, err = FAILED;
602	struct scsiback_tpg *tpg = pending_req->v2p->tpg;
603	struct se_cmd *se_cmd = &pending_req->se_cmd;
604	struct scsiback_tmr *tmr;
605
606	tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
607	if (!tmr)
608		goto out;
609
610	init_waitqueue_head(&tmr->tmr_wait);
611
612	transport_init_se_cmd(se_cmd, tpg->se_tpg.se_tpg_tfo,
613		tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, MSG_SIMPLE_TAG,
614		&pending_req->sense_buffer[0]);
615
616	rc = core_tmr_alloc_req(se_cmd, tmr, act, GFP_KERNEL);
617	if (rc < 0)
618		goto out;
619
620	se_cmd->se_tmr_req->ref_task_tag = tag;
621
622	if (transport_lookup_tmr_lun(se_cmd, pending_req->v2p->lun) < 0)
623		goto out;
624
625	transport_generic_handle_tmr(se_cmd);
626	wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
627
628	err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
629		SUCCESS : FAILED;
630
631out:
632	if (tmr) {
633		transport_generic_free_cmd(&pending_req->se_cmd, 1);
634		kfree(tmr);
635	}
636
637	scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
638
639	kmem_cache_free(scsiback_cachep, pending_req);
640}
641
642/*
643  Perform virtual to physical translation
644*/
645static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
646			struct ids_tuple *v)
647{
648	struct v2p_entry *entry;
649	struct list_head *head = &(info->v2p_entry_lists);
650	unsigned long flags;
651
652	spin_lock_irqsave(&info->v2p_lock, flags);
653	list_for_each_entry(entry, head, l) {
654		if ((entry->v.chn == v->chn) &&
655		    (entry->v.tgt == v->tgt) &&
656		    (entry->v.lun == v->lun)) {
657			kref_get(&entry->kref);
658			goto out;
659		}
660	}
661	entry = NULL;
662
663out:
664	spin_unlock_irqrestore(&info->v2p_lock, flags);
665	return entry;
666}
667
668static int prepare_pending_reqs(struct vscsibk_info *info,
669				struct vscsiif_request *ring_req,
670				struct vscsibk_pend *pending_req)
671{
672	struct v2p_entry *v2p;
673	struct ids_tuple vir;
674
675	pending_req->rqid       = ring_req->rqid;
676	pending_req->info       = info;
677
678	vir.chn = ring_req->channel;
679	vir.tgt = ring_req->id;
680	vir.lun = ring_req->lun;
681
682	v2p = scsiback_do_translation(info, &vir);
683	if (!v2p) {
684		pending_req->v2p = NULL;
685		DPRINTK("xen-pvscsi: doesn't exist.\n");
686		return -ENODEV;
687	}
688	pending_req->v2p = v2p;
689
690	/* request range check from frontend */
691	pending_req->sc_data_direction = ring_req->sc_data_direction;
692	if ((pending_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
693		(pending_req->sc_data_direction != DMA_TO_DEVICE) &&
694		(pending_req->sc_data_direction != DMA_FROM_DEVICE) &&
695		(pending_req->sc_data_direction != DMA_NONE)) {
696		DPRINTK("xen-pvscsi: invalid parameter data_dir = %d\n",
697			pending_req->sc_data_direction);
698		return -EINVAL;
699	}
700
701	pending_req->cmd_len = ring_req->cmd_len;
702	if (pending_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
703		DPRINTK("xen-pvscsi: invalid parameter cmd_len = %d\n",
704			pending_req->cmd_len);
705		return -EINVAL;
706	}
707	memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
708
709	return 0;
710}
711
712static int scsiback_do_cmd_fn(struct vscsibk_info *info)
713{
714	struct vscsiif_back_ring *ring = &info->ring;
715	struct vscsiif_request *ring_req;
716	struct vscsibk_pend *pending_req;
717	RING_IDX rc, rp;
718	int err, more_to_do;
719	uint32_t result;
720	uint8_t act;
721
722	rc = ring->req_cons;
723	rp = ring->sring->req_prod;
724	rmb();	/* guest system is accessing ring, too */
725
726	if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
727		rc = ring->rsp_prod_pvt;
728		pr_warn("xen-pvscsi: Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
729			   info->domid, rp, rc, rp - rc);
730		info->ring_error = 1;
731		return 0;
732	}
733
734	while ((rc != rp)) {
735		if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
736			break;
737		pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL);
738		if (!pending_req)
739			return 1;
740
741		ring_req = RING_GET_REQUEST(ring, rc);
742		ring->req_cons = ++rc;
743
744		act = ring_req->act;
745		err = prepare_pending_reqs(info, ring_req, pending_req);
746		if (err) {
747			switch (err) {
748			case -ENODEV:
749				result = DID_NO_CONNECT;
750				break;
751			default:
752				result = DRIVER_ERROR;
753				break;
754			}
755			scsiback_do_resp_with_sense(NULL, result << 24, 0,
756						    pending_req);
757			kmem_cache_free(scsiback_cachep, pending_req);
758			return 1;
759		}
760
761		switch (act) {
762		case VSCSIIF_ACT_SCSI_CDB:
763			if (scsiback_gnttab_data_map(ring_req, pending_req)) {
764				scsiback_fast_flush_area(pending_req);
765				scsiback_do_resp_with_sense(NULL,
766					DRIVER_ERROR << 24, 0, pending_req);
767				kmem_cache_free(scsiback_cachep, pending_req);
768			} else {
769				scsiback_cmd_exec(pending_req);
770			}
771			break;
772		case VSCSIIF_ACT_SCSI_ABORT:
773			scsiback_device_action(pending_req, TMR_ABORT_TASK,
774				ring_req->ref_rqid);
775			break;
776		case VSCSIIF_ACT_SCSI_RESET:
777			scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
778			break;
779		default:
780			pr_err_ratelimited("xen-pvscsi: invalid request\n");
781			scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24,
782						    0, pending_req);
783			kmem_cache_free(scsiback_cachep, pending_req);
784			break;
785		}
786
787		/* Yield point for this unbounded loop. */
788		cond_resched();
789	}
790
791	RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
792	return more_to_do;
793}
794
795static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
796{
797	struct vscsibk_info *info = dev_id;
798
799	if (info->ring_error)
800		return IRQ_HANDLED;
801
802	while (scsiback_do_cmd_fn(info))
803		cond_resched();
804
805	return IRQ_HANDLED;
806}
807
808static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
809			evtchn_port_t evtchn)
810{
811	void *area;
812	struct vscsiif_sring *sring;
813	int err;
814
815	if (info->irq)
816		return -1;
817
818	err = xenbus_map_ring_valloc(info->dev, ring_ref, &area);
819	if (err)
820		return err;
821
822	sring = (struct vscsiif_sring *)area;
823	BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
824
825	err = bind_interdomain_evtchn_to_irq(info->domid, evtchn);
826	if (err < 0)
827		goto unmap_page;
828
829	info->irq = err;
830
831	err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
832				   IRQF_ONESHOT, "vscsiif-backend", info);
833	if (err)
834		goto free_irq;
835
836	return 0;
837
838free_irq:
839	unbind_from_irqhandler(info->irq, info);
840	info->irq = 0;
841unmap_page:
842	xenbus_unmap_ring_vfree(info->dev, area);
843
844	return err;
845}
846
847static int scsiback_map(struct vscsibk_info *info)
848{
849	struct xenbus_device *dev = info->dev;
850	unsigned int ring_ref, evtchn;
851	int err;
852
853	err = xenbus_gather(XBT_NIL, dev->otherend,
854			"ring-ref", "%u", &ring_ref,
855			"event-channel", "%u", &evtchn, NULL);
856	if (err) {
857		xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
858		return err;
859	}
860
861	return scsiback_init_sring(info, ring_ref, evtchn);
862}
863
864/*
865  Add a new translation entry
866*/
867static int scsiback_add_translation_entry(struct vscsibk_info *info,
868					  char *phy, struct ids_tuple *v)
869{
870	int err = 0;
871	struct v2p_entry *entry;
872	struct v2p_entry *new;
873	struct list_head *head = &(info->v2p_entry_lists);
874	unsigned long flags;
875	char *lunp;
876	unsigned int lun;
877	struct scsiback_tpg *tpg_entry, *tpg = NULL;
878	char *error = "doesn't exist";
879
880	lunp = strrchr(phy, ':');
881	if (!lunp) {
882		pr_err("xen-pvscsi: illegal format of physical device %s\n",
883			phy);
884		return -EINVAL;
885	}
886	*lunp = 0;
887	lunp++;
888	if (kstrtouint(lunp, 10, &lun) || lun >= TRANSPORT_MAX_LUNS_PER_TPG) {
889		pr_err("xen-pvscsi: lun number not valid: %s\n", lunp);
890		return -EINVAL;
891	}
892
893	mutex_lock(&scsiback_mutex);
894	list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
895		if (!strcmp(phy, tpg_entry->tport->tport_name) ||
896		    !strcmp(phy, tpg_entry->param_alias)) {
897			spin_lock(&tpg_entry->se_tpg.tpg_lun_lock);
898			if (tpg_entry->se_tpg.tpg_lun_list[lun]->lun_status ==
899			    TRANSPORT_LUN_STATUS_ACTIVE) {
900				if (!tpg_entry->tpg_nexus)
901					error = "nexus undefined";
902				else
903					tpg = tpg_entry;
904			}
905			spin_unlock(&tpg_entry->se_tpg.tpg_lun_lock);
906			break;
907		}
908	}
909	if (tpg) {
910		mutex_lock(&tpg->tv_tpg_mutex);
911		tpg->tv_tpg_fe_count++;
912		mutex_unlock(&tpg->tv_tpg_mutex);
913	}
914	mutex_unlock(&scsiback_mutex);
915
916	if (!tpg) {
917		pr_err("xen-pvscsi: %s:%d %s\n", phy, lun, error);
918		return -ENODEV;
919	}
920
921	new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
922	if (new == NULL) {
923		err = -ENOMEM;
924		goto out_free;
925	}
926
927	spin_lock_irqsave(&info->v2p_lock, flags);
928
929	/* Check double assignment to identical virtual ID */
930	list_for_each_entry(entry, head, l) {
931		if ((entry->v.chn == v->chn) &&
932		    (entry->v.tgt == v->tgt) &&
933		    (entry->v.lun == v->lun)) {
934			pr_warn("xen-pvscsi: Virtual ID is already used. Assignment was not performed.\n");
935			err = -EEXIST;
936			goto out;
937		}
938
939	}
940
941	/* Create a new translation entry and add to the list */
942	kref_init(&new->kref);
943	new->v = *v;
944	new->tpg = tpg;
945	new->lun = lun;
946	list_add_tail(&new->l, head);
947
948out:
949	spin_unlock_irqrestore(&info->v2p_lock, flags);
950
951out_free:
952	mutex_lock(&tpg->tv_tpg_mutex);
953	tpg->tv_tpg_fe_count--;
954	mutex_unlock(&tpg->tv_tpg_mutex);
955
956	if (err)
957		kfree(new);
958
959	return err;
960}
961
962static void __scsiback_del_translation_entry(struct v2p_entry *entry)
963{
964	list_del(&entry->l);
965	kref_put(&entry->kref, scsiback_free_translation_entry);
966}
967
968/*
969  Delete the translation entry specfied
970*/
971static int scsiback_del_translation_entry(struct vscsibk_info *info,
972					  struct ids_tuple *v)
973{
974	struct v2p_entry *entry;
975	struct list_head *head = &(info->v2p_entry_lists);
976	unsigned long flags;
977
978	spin_lock_irqsave(&info->v2p_lock, flags);
979	/* Find out the translation entry specified */
980	list_for_each_entry(entry, head, l) {
981		if ((entry->v.chn == v->chn) &&
982		    (entry->v.tgt == v->tgt) &&
983		    (entry->v.lun == v->lun)) {
984			goto found;
985		}
986	}
987
988	spin_unlock_irqrestore(&info->v2p_lock, flags);
989	return 1;
990
991found:
992	/* Delete the translation entry specfied */
993	__scsiback_del_translation_entry(entry);
994
995	spin_unlock_irqrestore(&info->v2p_lock, flags);
996	return 0;
997}
998
999static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
1000				char *phy, struct ids_tuple *vir)
1001{
1002	if (!scsiback_add_translation_entry(info, phy, vir)) {
1003		if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1004				  "%d", XenbusStateInitialised)) {
1005			pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1006			scsiback_del_translation_entry(info, vir);
1007		}
1008	} else {
1009		xenbus_printf(XBT_NIL, info->dev->nodename, state,
1010			      "%d", XenbusStateClosed);
1011	}
1012}
1013
1014static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1015				struct ids_tuple *vir)
1016{
1017	if (!scsiback_del_translation_entry(info, vir)) {
1018		if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1019				  "%d", XenbusStateClosed))
1020			pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1021	}
1022}
1023
1024#define VSCSIBACK_OP_ADD_OR_DEL_LUN	1
1025#define VSCSIBACK_OP_UPDATEDEV_STATE	2
1026
1027static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1028				     char *ent)
1029{
1030	int err;
1031	struct ids_tuple vir;
1032	char *val;
1033	int device_state;
1034	char phy[VSCSI_NAMELEN];
1035	char str[64];
1036	char state[64];
1037	struct xenbus_device *dev = info->dev;
1038
1039	/* read status */
1040	snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1041	err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1042	if (XENBUS_EXIST_ERR(err))
1043		return;
1044
1045	/* physical SCSI device */
1046	snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1047	val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1048	if (IS_ERR(val)) {
1049		xenbus_printf(XBT_NIL, dev->nodename, state,
1050			      "%d", XenbusStateClosed);
1051		return;
1052	}
1053	strlcpy(phy, val, VSCSI_NAMELEN);
1054	kfree(val);
1055
1056	/* virtual SCSI device */
1057	snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1058	err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1059			   &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1060	if (XENBUS_EXIST_ERR(err)) {
1061		xenbus_printf(XBT_NIL, dev->nodename, state,
1062			      "%d", XenbusStateClosed);
1063		return;
1064	}
1065
1066	switch (op) {
1067	case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1068		if (device_state == XenbusStateInitialising)
1069			scsiback_do_add_lun(info, state, phy, &vir);
1070		if (device_state == XenbusStateClosing)
1071			scsiback_do_del_lun(info, state, &vir);
1072		break;
1073
1074	case VSCSIBACK_OP_UPDATEDEV_STATE:
1075		if (device_state == XenbusStateInitialised) {
1076			/* modify vscsi-devs/dev-x/state */
1077			if (xenbus_printf(XBT_NIL, dev->nodename, state,
1078					  "%d", XenbusStateConnected)) {
1079				pr_err("xen-pvscsi: xenbus_printf error %s\n",
1080				       str);
1081				scsiback_del_translation_entry(info, &vir);
1082				xenbus_printf(XBT_NIL, dev->nodename, state,
1083					      "%d", XenbusStateClosed);
1084			}
1085		}
1086		break;
1087	/*When it is necessary, processing is added here.*/
1088	default:
1089		break;
1090	}
1091}
1092
1093static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1094{
1095	int i;
1096	char **dir;
1097	unsigned int ndir = 0;
1098
1099	dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1100			       &ndir);
1101	if (IS_ERR(dir))
1102		return;
1103
1104	for (i = 0; i < ndir; i++)
1105		scsiback_do_1lun_hotplug(info, op, dir[i]);
1106
1107	kfree(dir);
1108}
1109
1110static void scsiback_frontend_changed(struct xenbus_device *dev,
1111					enum xenbus_state frontend_state)
1112{
1113	struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1114
1115	switch (frontend_state) {
1116	case XenbusStateInitialising:
1117		break;
1118
1119	case XenbusStateInitialised:
1120		if (scsiback_map(info))
1121			break;
1122
1123		scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1124		xenbus_switch_state(dev, XenbusStateConnected);
1125		break;
1126
1127	case XenbusStateConnected:
1128		scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1129
1130		if (dev->state == XenbusStateConnected)
1131			break;
1132
1133		xenbus_switch_state(dev, XenbusStateConnected);
1134		break;
1135
1136	case XenbusStateClosing:
1137		if (info->irq)
1138			scsiback_disconnect(info);
1139
1140		xenbus_switch_state(dev, XenbusStateClosing);
1141		break;
1142
1143	case XenbusStateClosed:
1144		xenbus_switch_state(dev, XenbusStateClosed);
1145		if (xenbus_dev_is_online(dev))
1146			break;
1147		/* fall through if not online */
1148	case XenbusStateUnknown:
1149		device_unregister(&dev->dev);
1150		break;
1151
1152	case XenbusStateReconfiguring:
1153		scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1154		xenbus_switch_state(dev, XenbusStateReconfigured);
1155
1156		break;
1157
1158	default:
1159		xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1160					frontend_state);
1161		break;
1162	}
1163}
1164
1165/*
1166  Release the translation entry specfied
1167*/
1168static void scsiback_release_translation_entry(struct vscsibk_info *info)
1169{
1170	struct v2p_entry *entry, *tmp;
1171	struct list_head *head = &(info->v2p_entry_lists);
1172	unsigned long flags;
1173
1174	spin_lock_irqsave(&info->v2p_lock, flags);
1175
1176	list_for_each_entry_safe(entry, tmp, head, l)
1177		__scsiback_del_translation_entry(entry);
1178
1179	spin_unlock_irqrestore(&info->v2p_lock, flags);
1180}
1181
1182static int scsiback_remove(struct xenbus_device *dev)
1183{
1184	struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1185
1186	if (info->irq)
1187		scsiback_disconnect(info);
1188
1189	scsiback_release_translation_entry(info);
1190
1191	dev_set_drvdata(&dev->dev, NULL);
1192
1193	return 0;
1194}
1195
1196static int scsiback_probe(struct xenbus_device *dev,
1197			   const struct xenbus_device_id *id)
1198{
1199	int err;
1200
1201	struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1202					    GFP_KERNEL);
1203
1204	DPRINTK("%p %d\n", dev, dev->otherend_id);
1205
1206	if (!info) {
1207		xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1208		return -ENOMEM;
1209	}
1210	info->dev = dev;
1211	dev_set_drvdata(&dev->dev, info);
1212
1213	info->domid = dev->otherend_id;
1214	spin_lock_init(&info->ring_lock);
1215	info->ring_error = 0;
1216	atomic_set(&info->nr_unreplied_reqs, 0);
1217	init_waitqueue_head(&info->waiting_to_free);
1218	info->dev = dev;
1219	info->irq = 0;
1220	INIT_LIST_HEAD(&info->v2p_entry_lists);
1221	spin_lock_init(&info->v2p_lock);
1222
1223	err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1224			    SG_ALL);
1225	if (err)
1226		xenbus_dev_error(dev, err, "writing feature-sg-grant");
1227
1228	err = xenbus_switch_state(dev, XenbusStateInitWait);
1229	if (err)
1230		goto fail;
1231
1232	return 0;
1233
1234fail:
1235	pr_warn("xen-pvscsi: %s failed\n", __func__);
1236	scsiback_remove(dev);
1237
1238	return err;
1239}
1240
1241static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1242{
1243	switch (tport->tport_proto_id) {
1244	case SCSI_PROTOCOL_SAS:
1245		return "SAS";
1246	case SCSI_PROTOCOL_FCP:
1247		return "FCP";
1248	case SCSI_PROTOCOL_ISCSI:
1249		return "iSCSI";
1250	default:
1251		break;
1252	}
1253
1254	return "Unknown";
1255}
1256
1257static u8 scsiback_get_fabric_proto_ident(struct se_portal_group *se_tpg)
1258{
1259	struct scsiback_tpg *tpg = container_of(se_tpg,
1260				struct scsiback_tpg, se_tpg);
1261	struct scsiback_tport *tport = tpg->tport;
1262
1263	switch (tport->tport_proto_id) {
1264	case SCSI_PROTOCOL_SAS:
1265		return sas_get_fabric_proto_ident(se_tpg);
1266	case SCSI_PROTOCOL_FCP:
1267		return fc_get_fabric_proto_ident(se_tpg);
1268	case SCSI_PROTOCOL_ISCSI:
1269		return iscsi_get_fabric_proto_ident(se_tpg);
1270	default:
1271		pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1272			tport->tport_proto_id);
1273		break;
1274	}
1275
1276	return sas_get_fabric_proto_ident(se_tpg);
1277}
1278
1279static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1280{
1281	struct scsiback_tpg *tpg = container_of(se_tpg,
1282				struct scsiback_tpg, se_tpg);
1283	struct scsiback_tport *tport = tpg->tport;
1284
1285	return &tport->tport_name[0];
1286}
1287
1288static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1289{
1290	struct scsiback_tpg *tpg = container_of(se_tpg,
1291				struct scsiback_tpg, se_tpg);
1292	return tpg->tport_tpgt;
1293}
1294
1295static u32 scsiback_get_default_depth(struct se_portal_group *se_tpg)
1296{
1297	return 1;
1298}
1299
1300static u32
1301scsiback_get_pr_transport_id(struct se_portal_group *se_tpg,
1302			      struct se_node_acl *se_nacl,
1303			      struct t10_pr_registration *pr_reg,
1304			      int *format_code,
1305			      unsigned char *buf)
1306{
1307	struct scsiback_tpg *tpg = container_of(se_tpg,
1308				struct scsiback_tpg, se_tpg);
1309	struct scsiback_tport *tport = tpg->tport;
1310
1311	switch (tport->tport_proto_id) {
1312	case SCSI_PROTOCOL_SAS:
1313		return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1314					format_code, buf);
1315	case SCSI_PROTOCOL_FCP:
1316		return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1317					format_code, buf);
1318	case SCSI_PROTOCOL_ISCSI:
1319		return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1320					format_code, buf);
1321	default:
1322		pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1323			tport->tport_proto_id);
1324		break;
1325	}
1326
1327	return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1328			format_code, buf);
1329}
1330
1331static u32
1332scsiback_get_pr_transport_id_len(struct se_portal_group *se_tpg,
1333				  struct se_node_acl *se_nacl,
1334				  struct t10_pr_registration *pr_reg,
1335				  int *format_code)
1336{
1337	struct scsiback_tpg *tpg = container_of(se_tpg,
1338				struct scsiback_tpg, se_tpg);
1339	struct scsiback_tport *tport = tpg->tport;
1340
1341	switch (tport->tport_proto_id) {
1342	case SCSI_PROTOCOL_SAS:
1343		return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1344					format_code);
1345	case SCSI_PROTOCOL_FCP:
1346		return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1347					format_code);
1348	case SCSI_PROTOCOL_ISCSI:
1349		return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1350					format_code);
1351	default:
1352		pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1353			tport->tport_proto_id);
1354		break;
1355	}
1356
1357	return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1358			format_code);
1359}
1360
1361static char *
1362scsiback_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
1363				    const char *buf,
1364				    u32 *out_tid_len,
1365				    char **port_nexus_ptr)
1366{
1367	struct scsiback_tpg *tpg = container_of(se_tpg,
1368				struct scsiback_tpg, se_tpg);
1369	struct scsiback_tport *tport = tpg->tport;
1370
1371	switch (tport->tport_proto_id) {
1372	case SCSI_PROTOCOL_SAS:
1373		return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1374					port_nexus_ptr);
1375	case SCSI_PROTOCOL_FCP:
1376		return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1377					port_nexus_ptr);
1378	case SCSI_PROTOCOL_ISCSI:
1379		return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1380					port_nexus_ptr);
1381	default:
1382		pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1383			tport->tport_proto_id);
1384		break;
1385	}
1386
1387	return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1388			port_nexus_ptr);
1389}
1390
1391static struct se_wwn *
1392scsiback_make_tport(struct target_fabric_configfs *tf,
1393		     struct config_group *group,
1394		     const char *name)
1395{
1396	struct scsiback_tport *tport;
1397	char *ptr;
1398	u64 wwpn = 0;
1399	int off = 0;
1400
1401	tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1402	if (!tport)
1403		return ERR_PTR(-ENOMEM);
1404
1405	tport->tport_wwpn = wwpn;
1406	/*
1407	 * Determine the emulated Protocol Identifier and Target Port Name
1408	 * based on the incoming configfs directory name.
1409	 */
1410	ptr = strstr(name, "naa.");
1411	if (ptr) {
1412		tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1413		goto check_len;
1414	}
1415	ptr = strstr(name, "fc.");
1416	if (ptr) {
1417		tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1418		off = 3; /* Skip over "fc." */
1419		goto check_len;
1420	}
1421	ptr = strstr(name, "iqn.");
1422	if (ptr) {
1423		tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1424		goto check_len;
1425	}
1426
1427	pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1428	kfree(tport);
1429	return ERR_PTR(-EINVAL);
1430
1431check_len:
1432	if (strlen(name) >= VSCSI_NAMELEN) {
1433		pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1434			scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1435		kfree(tport);
1436		return ERR_PTR(-EINVAL);
1437	}
1438	snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1439
1440	pr_debug("xen-pvscsi: Allocated emulated Target %s Address: %s\n",
1441		 scsiback_dump_proto_id(tport), name);
1442
1443	return &tport->tport_wwn;
1444}
1445
1446static void scsiback_drop_tport(struct se_wwn *wwn)
1447{
1448	struct scsiback_tport *tport = container_of(wwn,
1449				struct scsiback_tport, tport_wwn);
1450
1451	pr_debug("xen-pvscsi: Deallocating emulated Target %s Address: %s\n",
1452		 scsiback_dump_proto_id(tport), tport->tport_name);
1453
1454	kfree(tport);
1455}
1456
1457static struct se_node_acl *
1458scsiback_alloc_fabric_acl(struct se_portal_group *se_tpg)
1459{
1460	return kzalloc(sizeof(struct se_node_acl), GFP_KERNEL);
1461}
1462
1463static void
1464scsiback_release_fabric_acl(struct se_portal_group *se_tpg,
1465			     struct se_node_acl *se_nacl)
1466{
1467	kfree(se_nacl);
1468}
1469
1470static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1471{
1472	return 1;
1473}
1474
1475static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1476{
1477	/*
1478	 * Do not release struct se_cmd's containing a valid TMR
1479	 * pointer.  These will be released directly in scsiback_device_action()
1480	 * with transport_generic_free_cmd().
1481	 */
1482	if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1483		return 0;
1484
1485	transport_generic_free_cmd(se_cmd, 0);
1486	return 1;
1487}
1488
1489static void scsiback_release_cmd(struct se_cmd *se_cmd)
1490{
1491	struct vscsibk_pend *pending_req = container_of(se_cmd,
1492				struct vscsibk_pend, se_cmd);
1493
1494	kmem_cache_free(scsiback_cachep, pending_req);
1495}
1496
1497static int scsiback_shutdown_session(struct se_session *se_sess)
1498{
1499	return 0;
1500}
1501
1502static void scsiback_close_session(struct se_session *se_sess)
1503{
1504}
1505
1506static u32 scsiback_sess_get_index(struct se_session *se_sess)
1507{
1508	return 0;
1509}
1510
1511static int scsiback_write_pending(struct se_cmd *se_cmd)
1512{
1513	/* Go ahead and process the write immediately */
1514	target_execute_cmd(se_cmd);
1515
1516	return 0;
1517}
1518
1519static int scsiback_write_pending_status(struct se_cmd *se_cmd)
1520{
1521	return 0;
1522}
1523
1524static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1525{
1526}
1527
1528static u32 scsiback_get_task_tag(struct se_cmd *se_cmd)
1529{
1530	struct vscsibk_pend *pending_req = container_of(se_cmd,
1531				struct vscsibk_pend, se_cmd);
1532
1533	return pending_req->rqid;
1534}
1535
1536static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1537{
1538	return 0;
1539}
1540
1541static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1542{
1543	struct vscsibk_pend *pending_req = container_of(se_cmd,
1544				struct vscsibk_pend, se_cmd);
1545
1546	pending_req->result = SAM_STAT_GOOD;
1547	scsiback_cmd_done(pending_req);
1548	return 0;
1549}
1550
1551static int scsiback_queue_status(struct se_cmd *se_cmd)
1552{
1553	struct vscsibk_pend *pending_req = container_of(se_cmd,
1554				struct vscsibk_pend, se_cmd);
1555
1556	if (se_cmd->sense_buffer &&
1557	    ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1558	     (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1559		pending_req->result = (DRIVER_SENSE << 24) |
1560				      SAM_STAT_CHECK_CONDITION;
1561	else
1562		pending_req->result = se_cmd->scsi_status;
1563
1564	scsiback_cmd_done(pending_req);
1565	return 0;
1566}
1567
1568static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1569{
1570	struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
1571	struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr;
1572
1573	atomic_set(&tmr->tmr_complete, 1);
1574	wake_up(&tmr->tmr_wait);
1575}
1576
1577static void scsiback_aborted_task(struct se_cmd *se_cmd)
1578{
1579}
1580
1581static ssize_t scsiback_tpg_param_show_alias(struct se_portal_group *se_tpg,
1582					     char *page)
1583{
1584	struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1585						se_tpg);
1586	ssize_t rb;
1587
1588	mutex_lock(&tpg->tv_tpg_mutex);
1589	rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1590	mutex_unlock(&tpg->tv_tpg_mutex);
1591
1592	return rb;
1593}
1594
1595static ssize_t scsiback_tpg_param_store_alias(struct se_portal_group *se_tpg,
1596					      const char *page, size_t count)
1597{
1598	struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1599						se_tpg);
1600	int len;
1601
1602	if (strlen(page) >= VSCSI_NAMELEN) {
1603		pr_err("param alias: %s, exceeds max: %d\n", page,
1604			VSCSI_NAMELEN);
1605		return -EINVAL;
1606	}
1607
1608	mutex_lock(&tpg->tv_tpg_mutex);
1609	len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1610	if (tpg->param_alias[len - 1] == '\n')
1611		tpg->param_alias[len - 1] = '\0';
1612	mutex_unlock(&tpg->tv_tpg_mutex);
1613
1614	return count;
1615}
1616
1617TF_TPG_PARAM_ATTR(scsiback, alias, S_IRUGO | S_IWUSR);
1618
1619static struct configfs_attribute *scsiback_param_attrs[] = {
1620	&scsiback_tpg_param_alias.attr,
1621	NULL,
1622};
1623
1624static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1625				const char *name)
1626{
1627	struct se_portal_group *se_tpg;
1628	struct se_session *se_sess;
1629	struct scsiback_nexus *tv_nexus;
1630
1631	mutex_lock(&tpg->tv_tpg_mutex);
1632	if (tpg->tpg_nexus) {
1633		mutex_unlock(&tpg->tv_tpg_mutex);
1634		pr_debug("tpg->tpg_nexus already exists\n");
1635		return -EEXIST;
1636	}
1637	se_tpg = &tpg->se_tpg;
1638
1639	tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1640	if (!tv_nexus) {
1641		mutex_unlock(&tpg->tv_tpg_mutex);
1642		return -ENOMEM;
1643	}
1644	/*
1645	 *  Initialize the struct se_session pointer
1646	 */
1647	tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_NORMAL);
1648	if (IS_ERR(tv_nexus->tvn_se_sess)) {
1649		mutex_unlock(&tpg->tv_tpg_mutex);
1650		kfree(tv_nexus);
1651		return -ENOMEM;
1652	}
1653	se_sess = tv_nexus->tvn_se_sess;
1654	/*
1655	 * Since we are running in 'demo mode' this call with generate a
1656	 * struct se_node_acl for the scsiback struct se_portal_group with
1657	 * the SCSI Initiator port name of the passed configfs group 'name'.
1658	 */
1659	tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1660				se_tpg, (unsigned char *)name);
1661	if (!tv_nexus->tvn_se_sess->se_node_acl) {
1662		mutex_unlock(&tpg->tv_tpg_mutex);
1663		pr_debug("core_tpg_check_initiator_node_acl() failed for %s\n",
1664			 name);
1665		goto out;
1666	}
1667	/*
1668	 * Now register the TCM pvscsi virtual I_T Nexus as active with the
1669	 * call to __transport_register_session()
1670	 */
1671	__transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
1672			tv_nexus->tvn_se_sess, tv_nexus);
1673	tpg->tpg_nexus = tv_nexus;
1674
1675	mutex_unlock(&tpg->tv_tpg_mutex);
1676	return 0;
1677
1678out:
1679	transport_free_session(se_sess);
1680	kfree(tv_nexus);
1681	return -ENOMEM;
1682}
1683
1684static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1685{
1686	struct se_session *se_sess;
1687	struct scsiback_nexus *tv_nexus;
1688
1689	mutex_lock(&tpg->tv_tpg_mutex);
1690	tv_nexus = tpg->tpg_nexus;
1691	if (!tv_nexus) {
1692		mutex_unlock(&tpg->tv_tpg_mutex);
1693		return -ENODEV;
1694	}
1695
1696	se_sess = tv_nexus->tvn_se_sess;
1697	if (!se_sess) {
1698		mutex_unlock(&tpg->tv_tpg_mutex);
1699		return -ENODEV;
1700	}
1701
1702	if (tpg->tv_tpg_port_count != 0) {
1703		mutex_unlock(&tpg->tv_tpg_mutex);
1704		pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1705			tpg->tv_tpg_port_count);
1706		return -EBUSY;
1707	}
1708
1709	if (tpg->tv_tpg_fe_count != 0) {
1710		mutex_unlock(&tpg->tv_tpg_mutex);
1711		pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1712			tpg->tv_tpg_fe_count);
1713		return -EBUSY;
1714	}
1715
1716	pr_debug("xen-pvscsi: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1717		scsiback_dump_proto_id(tpg->tport),
1718		tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1719
1720	/*
1721	 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1722	 */
1723	transport_deregister_session(tv_nexus->tvn_se_sess);
1724	tpg->tpg_nexus = NULL;
1725	mutex_unlock(&tpg->tv_tpg_mutex);
1726
1727	kfree(tv_nexus);
1728	return 0;
1729}
1730
1731static ssize_t scsiback_tpg_show_nexus(struct se_portal_group *se_tpg,
1732					char *page)
1733{
1734	struct scsiback_tpg *tpg = container_of(se_tpg,
1735				struct scsiback_tpg, se_tpg);
1736	struct scsiback_nexus *tv_nexus;
1737	ssize_t ret;
1738
1739	mutex_lock(&tpg->tv_tpg_mutex);
1740	tv_nexus = tpg->tpg_nexus;
1741	if (!tv_nexus) {
1742		mutex_unlock(&tpg->tv_tpg_mutex);
1743		return -ENODEV;
1744	}
1745	ret = snprintf(page, PAGE_SIZE, "%s\n",
1746			tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1747	mutex_unlock(&tpg->tv_tpg_mutex);
1748
1749	return ret;
1750}
1751
1752static ssize_t scsiback_tpg_store_nexus(struct se_portal_group *se_tpg,
1753					 const char *page,
1754					 size_t count)
1755{
1756	struct scsiback_tpg *tpg = container_of(se_tpg,
1757				struct scsiback_tpg, se_tpg);
1758	struct scsiback_tport *tport_wwn = tpg->tport;
1759	unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1760	int ret;
1761	/*
1762	 * Shutdown the active I_T nexus if 'NULL' is passed..
1763	 */
1764	if (!strncmp(page, "NULL", 4)) {
1765		ret = scsiback_drop_nexus(tpg);
1766		return (!ret) ? count : ret;
1767	}
1768	/*
1769	 * Otherwise make sure the passed virtual Initiator port WWN matches
1770	 * the fabric protocol_id set in scsiback_make_tport(), and call
1771	 * scsiback_make_nexus().
1772	 */
1773	if (strlen(page) >= VSCSI_NAMELEN) {
1774		pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1775			page, VSCSI_NAMELEN);
1776		return -EINVAL;
1777	}
1778	snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1779
1780	ptr = strstr(i_port, "naa.");
1781	if (ptr) {
1782		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1783			pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1784				i_port, scsiback_dump_proto_id(tport_wwn));
1785			return -EINVAL;
1786		}
1787		port_ptr = &i_port[0];
1788		goto check_newline;
1789	}
1790	ptr = strstr(i_port, "fc.");
1791	if (ptr) {
1792		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1793			pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1794				i_port, scsiback_dump_proto_id(tport_wwn));
1795			return -EINVAL;
1796		}
1797		port_ptr = &i_port[3]; /* Skip over "fc." */
1798		goto check_newline;
1799	}
1800	ptr = strstr(i_port, "iqn.");
1801	if (ptr) {
1802		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1803			pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1804				i_port, scsiback_dump_proto_id(tport_wwn));
1805			return -EINVAL;
1806		}
1807		port_ptr = &i_port[0];
1808		goto check_newline;
1809	}
1810	pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1811		i_port);
1812	return -EINVAL;
1813	/*
1814	 * Clear any trailing newline for the NAA WWN
1815	 */
1816check_newline:
1817	if (i_port[strlen(i_port) - 1] == '\n')
1818		i_port[strlen(i_port) - 1] = '\0';
1819
1820	ret = scsiback_make_nexus(tpg, port_ptr);
1821	if (ret < 0)
1822		return ret;
1823
1824	return count;
1825}
1826
1827TF_TPG_BASE_ATTR(scsiback, nexus, S_IRUGO | S_IWUSR);
1828
1829static struct configfs_attribute *scsiback_tpg_attrs[] = {
1830	&scsiback_tpg_nexus.attr,
1831	NULL,
1832};
1833
1834static ssize_t
1835scsiback_wwn_show_attr_version(struct target_fabric_configfs *tf,
1836				char *page)
1837{
1838	return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1839		UTS_RELEASE"\n",
1840		VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1841}
1842
1843TF_WWN_ATTR_RO(scsiback, version);
1844
1845static struct configfs_attribute *scsiback_wwn_attrs[] = {
1846	&scsiback_wwn_version.attr,
1847	NULL,
1848};
1849
1850static char *scsiback_get_fabric_name(void)
1851{
1852	return "xen-pvscsi";
1853}
1854
1855static int scsiback_port_link(struct se_portal_group *se_tpg,
1856			       struct se_lun *lun)
1857{
1858	struct scsiback_tpg *tpg = container_of(se_tpg,
1859				struct scsiback_tpg, se_tpg);
1860
1861	mutex_lock(&tpg->tv_tpg_mutex);
1862	tpg->tv_tpg_port_count++;
1863	mutex_unlock(&tpg->tv_tpg_mutex);
1864
1865	return 0;
1866}
1867
1868static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1869				  struct se_lun *lun)
1870{
1871	struct scsiback_tpg *tpg = container_of(se_tpg,
1872				struct scsiback_tpg, se_tpg);
1873
1874	mutex_lock(&tpg->tv_tpg_mutex);
1875	tpg->tv_tpg_port_count--;
1876	mutex_unlock(&tpg->tv_tpg_mutex);
1877}
1878
1879static struct se_portal_group *
1880scsiback_make_tpg(struct se_wwn *wwn,
1881		   struct config_group *group,
1882		   const char *name)
1883{
1884	struct scsiback_tport *tport = container_of(wwn,
1885			struct scsiback_tport, tport_wwn);
1886
1887	struct scsiback_tpg *tpg;
1888	u16 tpgt;
1889	int ret;
1890
1891	if (strstr(name, "tpgt_") != name)
1892		return ERR_PTR(-EINVAL);
1893	ret = kstrtou16(name + 5, 10, &tpgt);
1894	if (ret)
1895		return ERR_PTR(ret);
1896
1897	tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1898	if (!tpg)
1899		return ERR_PTR(-ENOMEM);
1900
1901	mutex_init(&tpg->tv_tpg_mutex);
1902	INIT_LIST_HEAD(&tpg->tv_tpg_list);
1903	INIT_LIST_HEAD(&tpg->info_list);
1904	tpg->tport = tport;
1905	tpg->tport_tpgt = tpgt;
1906
1907	ret = core_tpg_register(&scsiback_fabric_configfs->tf_ops, wwn,
1908				&tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
1909	if (ret < 0) {
1910		kfree(tpg);
1911		return NULL;
1912	}
1913	mutex_lock(&scsiback_mutex);
1914	list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1915	mutex_unlock(&scsiback_mutex);
1916
1917	return &tpg->se_tpg;
1918}
1919
1920static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1921{
1922	struct scsiback_tpg *tpg = container_of(se_tpg,
1923				struct scsiback_tpg, se_tpg);
1924
1925	mutex_lock(&scsiback_mutex);
1926	list_del(&tpg->tv_tpg_list);
1927	mutex_unlock(&scsiback_mutex);
1928	/*
1929	 * Release the virtual I_T Nexus for this xen-pvscsi TPG
1930	 */
1931	scsiback_drop_nexus(tpg);
1932	/*
1933	 * Deregister the se_tpg from TCM..
1934	 */
1935	core_tpg_deregister(se_tpg);
1936	kfree(tpg);
1937}
1938
1939static int scsiback_check_true(struct se_portal_group *se_tpg)
1940{
1941	return 1;
1942}
1943
1944static int scsiback_check_false(struct se_portal_group *se_tpg)
1945{
1946	return 0;
1947}
1948
1949static struct target_core_fabric_ops scsiback_ops = {
1950	.get_fabric_name		= scsiback_get_fabric_name,
1951	.get_fabric_proto_ident		= scsiback_get_fabric_proto_ident,
1952	.tpg_get_wwn			= scsiback_get_fabric_wwn,
1953	.tpg_get_tag			= scsiback_get_tag,
1954	.tpg_get_default_depth		= scsiback_get_default_depth,
1955	.tpg_get_pr_transport_id	= scsiback_get_pr_transport_id,
1956	.tpg_get_pr_transport_id_len	= scsiback_get_pr_transport_id_len,
1957	.tpg_parse_pr_out_transport_id	= scsiback_parse_pr_out_transport_id,
1958	.tpg_check_demo_mode		= scsiback_check_true,
1959	.tpg_check_demo_mode_cache	= scsiback_check_true,
1960	.tpg_check_demo_mode_write_protect = scsiback_check_false,
1961	.tpg_check_prod_mode_write_protect = scsiback_check_false,
1962	.tpg_alloc_fabric_acl		= scsiback_alloc_fabric_acl,
1963	.tpg_release_fabric_acl		= scsiback_release_fabric_acl,
1964	.tpg_get_inst_index		= scsiback_tpg_get_inst_index,
1965	.check_stop_free		= scsiback_check_stop_free,
1966	.release_cmd			= scsiback_release_cmd,
1967	.put_session			= NULL,
1968	.shutdown_session		= scsiback_shutdown_session,
1969	.close_session			= scsiback_close_session,
1970	.sess_get_index			= scsiback_sess_get_index,
1971	.sess_get_initiator_sid		= NULL,
1972	.write_pending			= scsiback_write_pending,
1973	.write_pending_status		= scsiback_write_pending_status,
1974	.set_default_node_attributes	= scsiback_set_default_node_attrs,
1975	.get_task_tag			= scsiback_get_task_tag,
1976	.get_cmd_state			= scsiback_get_cmd_state,
1977	.queue_data_in			= scsiback_queue_data_in,
1978	.queue_status			= scsiback_queue_status,
1979	.queue_tm_rsp			= scsiback_queue_tm_rsp,
1980	.aborted_task			= scsiback_aborted_task,
1981	/*
1982	 * Setup callers for generic logic in target_core_fabric_configfs.c
1983	 */
1984	.fabric_make_wwn		= scsiback_make_tport,
1985	.fabric_drop_wwn		= scsiback_drop_tport,
1986	.fabric_make_tpg		= scsiback_make_tpg,
1987	.fabric_drop_tpg		= scsiback_drop_tpg,
1988	.fabric_post_link		= scsiback_port_link,
1989	.fabric_pre_unlink		= scsiback_port_unlink,
1990	.fabric_make_np			= NULL,
1991	.fabric_drop_np			= NULL,
1992#if 0
1993	.fabric_make_nodeacl		= scsiback_make_nodeacl,
1994	.fabric_drop_nodeacl		= scsiback_drop_nodeacl,
1995#endif
1996};
1997
1998static int scsiback_register_configfs(void)
1999{
2000	struct target_fabric_configfs *fabric;
2001	int ret;
2002
2003	pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
2004		 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
2005	/*
2006	 * Register the top level struct config_item_type with TCM core
2007	 */
2008	fabric = target_fabric_configfs_init(THIS_MODULE, "xen-pvscsi");
2009	if (IS_ERR(fabric))
2010		return PTR_ERR(fabric);
2011
2012	/*
2013	 * Setup fabric->tf_ops from our local scsiback_ops
2014	 */
2015	fabric->tf_ops = scsiback_ops;
2016	/*
2017	 * Setup default attribute lists for various fabric->tf_cit_tmpl
2018	 */
2019	fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = scsiback_wwn_attrs;
2020	fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = scsiback_tpg_attrs;
2021	fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
2022	fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = scsiback_param_attrs;
2023	fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
2024	fabric->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
2025	fabric->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
2026	fabric->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
2027	fabric->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
2028	/*
2029	 * Register the fabric for use within TCM
2030	 */
2031	ret = target_fabric_configfs_register(fabric);
2032	if (ret < 0) {
2033		target_fabric_configfs_free(fabric);
2034		return ret;
2035	}
2036	/*
2037	 * Setup our local pointer to *fabric
2038	 */
2039	scsiback_fabric_configfs = fabric;
2040	pr_debug("xen-pvscsi: Set fabric -> scsiback_fabric_configfs\n");
2041	return 0;
2042};
2043
2044static void scsiback_deregister_configfs(void)
2045{
2046	if (!scsiback_fabric_configfs)
2047		return;
2048
2049	target_fabric_configfs_deregister(scsiback_fabric_configfs);
2050	scsiback_fabric_configfs = NULL;
2051	pr_debug("xen-pvscsi: Cleared scsiback_fabric_configfs\n");
2052};
2053
2054static const struct xenbus_device_id scsiback_ids[] = {
2055	{ "vscsi" },
2056	{ "" }
2057};
2058
2059static struct xenbus_driver scsiback_driver = {
2060	.ids			= scsiback_ids,
2061	.probe			= scsiback_probe,
2062	.remove			= scsiback_remove,
2063	.otherend_changed	= scsiback_frontend_changed
2064};
2065
2066static void scsiback_init_pend(void *p)
2067{
2068	struct vscsibk_pend *pend = p;
2069	int i;
2070
2071	memset(pend, 0, sizeof(*pend));
2072	for (i = 0; i < VSCSI_MAX_GRANTS; i++)
2073		pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
2074}
2075
2076static int __init scsiback_init(void)
2077{
2078	int ret;
2079
2080	if (!xen_domain())
2081		return -ENODEV;
2082
2083	scsiback_cachep = kmem_cache_create("vscsiif_cache",
2084		sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
2085	if (!scsiback_cachep)
2086		return -ENOMEM;
2087
2088	ret = xenbus_register_backend(&scsiback_driver);
2089	if (ret)
2090		goto out_cache_destroy;
2091
2092	ret = scsiback_register_configfs();
2093	if (ret)
2094		goto out_unregister_xenbus;
2095
2096	return 0;
2097
2098out_unregister_xenbus:
2099	xenbus_unregister_driver(&scsiback_driver);
2100out_cache_destroy:
2101	kmem_cache_destroy(scsiback_cachep);
2102	pr_err("xen-pvscsi: %s: error %d\n", __func__, ret);
2103	return ret;
2104}
2105
2106static void __exit scsiback_exit(void)
2107{
2108	struct page *page;
2109
2110	while (free_pages_num) {
2111		if (get_free_page(&page))
2112			BUG();
2113		free_xenballooned_pages(1, &page);
2114	}
2115	scsiback_deregister_configfs();
2116	xenbus_unregister_driver(&scsiback_driver);
2117	kmem_cache_destroy(scsiback_cachep);
2118}
2119
2120module_init(scsiback_init);
2121module_exit(scsiback_exit);
2122
2123MODULE_DESCRIPTION("Xen SCSI backend driver");
2124MODULE_LICENSE("Dual BSD/GPL");
2125MODULE_ALIAS("xen-backend:vscsi");
2126MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
2127