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Merge remote-tracking branches 'spi/topic/acpi', 'spi/topic/axi-engine', 'spi/topic...
[linux-2.6-block.git] / drivers / xen / xen-scsiback.c
CommitLineData
d9d660f6
JG		 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
78574878
TC		 34#define pr_fmt(fmt) "xen-pvscsi: " fmt
35
d9d660f6
JG		 36#include <stdarg.h>
37
38#include <linux/module.h>
39#include <linux/utsname.h>
40#include <linux/interrupt.h>
41#include <linux/slab.h>
42#include <linux/wait.h>
43#include <linux/sched.h>
44#include <linux/list.h>
45#include <linux/gfp.h>
46#include <linux/delay.h>
47#include <linux/spinlock.h>
48#include <linux/configfs.h>
49
50#include <generated/utsrelease.h>
51
ba929992 52#include <scsi/scsi_host.h> /* SG_ALL */
d9d660f6
JG		 53
54#include <target/target_core_base.h>
55#include <target/target_core_fabric.h>
d9d660f6
JG		 56
57#include <asm/hypervisor.h>
58
59#include <xen/xen.h>
60#include <xen/balloon.h>
61#include <xen/events.h>
62#include <xen/xenbus.h>
63#include <xen/grant_table.h>
64#include <xen/page.h>
65
66#include <xen/interface/grant_table.h>
67#include <xen/interface/io/vscsiif.h>
68
d9d660f6
JG		 69#define VSCSI_VERSION "v0.1"
70#define VSCSI_NAMELEN 32
71
72struct ids_tuple {
73 unsigned int hst; /* host */
74 unsigned int chn; /* channel */
75 unsigned int tgt; /* target */
76 unsigned int lun; /* LUN */
77};
78
79struct v2p_entry {
80 struct ids_tuple v; /* translate from */
81 struct scsiback_tpg *tpg; /* translate to */
82 unsigned int lun;
83 struct kref kref;
84 struct list_head l;
85};
86
87struct vscsibk_info {
88 struct xenbus_device *dev;
89
90 domid_t domid;
91 unsigned int irq;
92
93 struct vscsiif_back_ring ring;
94 int ring_error;
95
96 spinlock_t ring_lock;
97 atomic_t nr_unreplied_reqs;
98
99 spinlock_t v2p_lock;
100 struct list_head v2p_entry_lists;
101
102 wait_queue_head_t waiting_to_free;
103};
104
105/* theoretical maximum of grants for one request */
106#define VSCSI_MAX_GRANTS (SG_ALL + VSCSIIF_SG_TABLESIZE)
107
108/*
109 * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
110 * call to map/unmap grants. Don't choose it too large, as there are arrays
111 * with VSCSI_GRANT_BATCH elements allocated on the stack.
112 */
113#define VSCSI_GRANT_BATCH 16
114
115struct vscsibk_pend {
116 uint16_t rqid;
117
118 uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
119 uint8_t cmd_len;
120
121 uint8_t sc_data_direction;
122 uint16_t n_sg; /* real length of SG list */
123 uint16_t n_grants; /* SG pages and potentially SG list */
124 uint32_t data_len;
125 uint32_t result;
126
127 struct vscsibk_info *info;
128 struct v2p_entry *v2p;
129 struct scatterlist *sgl;
130
131 uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
132
133 grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
134 struct page *pages[VSCSI_MAX_GRANTS];
135
136 struct se_cmd se_cmd;
137};
138
139struct scsiback_tmr {
140 atomic_t tmr_complete;
141 wait_queue_head_t tmr_wait;
142};
143
144struct scsiback_nexus {
145 /* Pointer to TCM session for I_T Nexus */
146 struct se_session *tvn_se_sess;
147};
148
149struct scsiback_tport {
150 /* SCSI protocol the tport is providing */
151 u8 tport_proto_id;
152 /* Binary World Wide unique Port Name for pvscsi Target port */
153 u64 tport_wwpn;
154 /* ASCII formatted WWPN for pvscsi Target port */
155 char tport_name[VSCSI_NAMELEN];
156 /* Returned by scsiback_make_tport() */
157 struct se_wwn tport_wwn;
158};
159
160struct scsiback_tpg {
161 /* scsiback port target portal group tag for TCM */
162 u16 tport_tpgt;
163 /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
164 int tv_tpg_port_count;
165 /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
166 int tv_tpg_fe_count;
167 /* list for scsiback_list */
168 struct list_head tv_tpg_list;
169 /* Used to protect access for tpg_nexus */
170 struct mutex tv_tpg_mutex;
171 /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
172 struct scsiback_nexus *tpg_nexus;
173 /* Pointer back to scsiback_tport */
174 struct scsiback_tport *tport;
175 /* Returned by scsiback_make_tpg() */
176 struct se_portal_group se_tpg;
177 /* alias used in xenstore */
178 char param_alias[VSCSI_NAMELEN];
179 /* list of info structures related to this target portal group */
180 struct list_head info_list;
181};
182
183#define SCSIBACK_INVALID_HANDLE (~0)
184
185static bool log_print_stat;
186module_param(log_print_stat, bool, 0644);
187
188static int scsiback_max_buffer_pages = 1024;
189module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
190MODULE_PARM_DESC(max_buffer_pages,
191"Maximum number of free pages to keep in backend buffer");
192
193static struct kmem_cache *scsiback_cachep;
194static DEFINE_SPINLOCK(free_pages_lock);
195static int free_pages_num;
196static LIST_HEAD(scsiback_free_pages);
197
198/* Global spinlock to protect scsiback TPG list */
199static DEFINE_MUTEX(scsiback_mutex);
200static LIST_HEAD(scsiback_list);
201
d9d660f6
JG		 202static void scsiback_get(struct vscsibk_info *info)
203{
204 atomic_inc(&info->nr_unreplied_reqs);
205}
206
207static void scsiback_put(struct vscsibk_info *info)
208{
209 if (atomic_dec_and_test(&info->nr_unreplied_reqs))
210 wake_up(&info->waiting_to_free);
211}
212
213static void put_free_pages(struct page **page, int num)
214{
215 unsigned long flags;
216 int i = free_pages_num + num, n = num;
217
218 if (num == 0)
219 return;
220 if (i > scsiback_max_buffer_pages) {
221 n = min(num, i - scsiback_max_buffer_pages);
ff4b156f 222 gnttab_free_pages(n, page + num - n);
d9d660f6
JG		 223 n = num - n;
224 }
225 spin_lock_irqsave(&free_pages_lock, flags);
226 for (i = 0; i < n; i++)
227 list_add(&page[i]->lru, &scsiback_free_pages);
228 free_pages_num += n;
229 spin_unlock_irqrestore(&free_pages_lock, flags);
230}
231
232static int get_free_page(struct page **page)
233{
234 unsigned long flags;
235
236 spin_lock_irqsave(&free_pages_lock, flags);
237 if (list_empty(&scsiback_free_pages)) {
238 spin_unlock_irqrestore(&free_pages_lock, flags);
ff4b156f 239 return gnttab_alloc_pages(1, page);
d9d660f6
JG		 240 }
241 page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
242 list_del(&page[0]->lru);
243 free_pages_num--;
244 spin_unlock_irqrestore(&free_pages_lock, flags);
245 return 0;
246}
247
248static unsigned long vaddr_page(struct page *page)
249{
250 unsigned long pfn = page_to_pfn(page);
251
252 return (unsigned long)pfn_to_kaddr(pfn);
253}
254
255static unsigned long vaddr(struct vscsibk_pend *req, int seg)
256{
257 return vaddr_page(req->pages[seg]);
258}
259
260static void scsiback_print_status(char *sense_buffer, int errors,
261 struct vscsibk_pend *pending_req)
262{
263 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
264
78574878 265 pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n",
d9d660f6
JG		 266 tpg->tport->tport_name, pending_req->v2p->lun,
267 pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
268 host_byte(errors), driver_byte(errors));
d9d660f6
JG		 269}
270
271static void scsiback_fast_flush_area(struct vscsibk_pend *req)
272{
273 struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
274 struct page *pages[VSCSI_GRANT_BATCH];
275 unsigned int i, invcount = 0;
276 grant_handle_t handle;
277 int err;
278
279 kfree(req->sgl);
280 req->sgl = NULL;
281 req->n_sg = 0;
282
283 if (!req->n_grants)
284 return;
285
286 for (i = 0; i < req->n_grants; i++) {
287 handle = req->grant_handles[i];
288 if (handle == SCSIBACK_INVALID_HANDLE)
289 continue;
290 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
291 GNTMAP_host_map, handle);
292 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
293 pages[invcount] = req->pages[i];
294 put_page(pages[invcount]);
295 invcount++;
296 if (invcount < VSCSI_GRANT_BATCH)
297 continue;
298 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
299 BUG_ON(err);
300 invcount = 0;
301 }
302
303 if (invcount) {
304 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
305 BUG_ON(err);
306 }
307
308 put_free_pages(req->pages, req->n_grants);
309 req->n_grants = 0;
310}
311
312static void scsiback_free_translation_entry(struct kref *kref)
313{
314 struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
315 struct scsiback_tpg *tpg = entry->tpg;
316
317 mutex_lock(&tpg->tv_tpg_mutex);
318 tpg->tv_tpg_fe_count--;
319 mutex_unlock(&tpg->tv_tpg_mutex);
320
321 kfree(entry);
322}
323
324static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
325 uint32_t resid, struct vscsibk_pend *pending_req)
326{
327 struct vscsiif_response *ring_res;
328 struct vscsibk_info *info = pending_req->info;
329 int notify;
330 struct scsi_sense_hdr sshdr;
331 unsigned long flags;
332 unsigned len;
333
334 spin_lock_irqsave(&info->ring_lock, flags);
335
336 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
337 info->ring.rsp_prod_pvt++;
338
339 ring_res->rslt = result;
340 ring_res->rqid = pending_req->rqid;
341
342 if (sense_buffer != NULL &&
343 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
344 &sshdr)) {
345 len = min_t(unsigned, 8 + sense_buffer[7],
346 VSCSIIF_SENSE_BUFFERSIZE);
347 memcpy(ring_res->sense_buffer, sense_buffer, len);
348 ring_res->sense_len = len;
349 } else {
350 ring_res->sense_len = 0;
351 }
352
353 ring_res->residual_len = resid;
354
355 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
356 spin_unlock_irqrestore(&info->ring_lock, flags);
357
358 if (notify)
359 notify_remote_via_irq(info->irq);
360
361 if (pending_req->v2p)
362 kref_put(&pending_req->v2p->kref,
363 scsiback_free_translation_entry);
364}
365
366static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
367{
368 struct vscsibk_info *info = pending_req->info;
369 unsigned char *sense_buffer;
370 unsigned int resid;
371 int errors;
372
373 sense_buffer = pending_req->sense_buffer;
374 resid = pending_req->se_cmd.residual_count;
375 errors = pending_req->result;
376
377 if (errors && log_print_stat)
378 scsiback_print_status(sense_buffer, errors, pending_req);
379
380 scsiback_fast_flush_area(pending_req);
381 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
382 scsiback_put(info);
383}
384
385static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
386{
387 struct se_cmd *se_cmd = &pending_req->se_cmd;
388 struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
389 int rc;
390
391 memset(pending_req->sense_buffer, 0, VSCSIIF_SENSE_BUFFERSIZE);
392
393 memset(se_cmd, 0, sizeof(*se_cmd));
394
395 scsiback_get(pending_req->info);
649ee054 396 se_cmd->tag = pending_req->rqid;
d9d660f6
JG		 397 rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
398 pending_req->sense_buffer, pending_req->v2p->lun,
399 pending_req->data_len, 0,
400 pending_req->sc_data_direction, 0,
401 pending_req->sgl, pending_req->n_sg,
402 NULL, 0, NULL, 0);
403 if (rc < 0) {
404 transport_send_check_condition_and_sense(se_cmd,
405 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
406 transport_generic_free_cmd(se_cmd, 0);
407 }
408}
409
410static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
411 struct page **pg, grant_handle_t *grant, int cnt)
412{
413 int err, i;
414
415 if (!cnt)
416 return 0;
417
418 err = gnttab_map_refs(map, NULL, pg, cnt);
419 BUG_ON(err);
420 for (i = 0; i < cnt; i++) {
421 if (unlikely(map[i].status != GNTST_okay)) {
78574878 422 pr_err("invalid buffer -- could not remap it\n");
d9d660f6
JG		 423 map[i].handle = SCSIBACK_INVALID_HANDLE;
424 err = -ENOMEM;
425 } else {
426 get_page(pg[i]);
427 }
428 grant[i] = map[i].handle;
429 }
430 return err;
431}
432
433static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
434 struct scsiif_request_segment *seg, struct page **pg,
435 grant_handle_t *grant, int cnt, u32 flags)
436{
437 int mapcount = 0, i, err = 0;
438 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
439 struct vscsibk_info *info = pending_req->info;
440
441 for (i = 0; i < cnt; i++) {
442 if (get_free_page(pg + mapcount)) {
443 put_free_pages(pg, mapcount);
78574878 444 pr_err("no grant page\n");
d9d660f6
JG		 445 return -ENOMEM;
446 }
447 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
448 flags, seg[i].gref, info->domid);
449 mapcount++;
450 if (mapcount < VSCSI_GRANT_BATCH)
451 continue;
452 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
453 pg += mapcount;
454 grant += mapcount;
455 pending_req->n_grants += mapcount;
456 if (err)
457 return err;
458 mapcount = 0;
459 }
460 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
461 pending_req->n_grants += mapcount;
462 return err;
463}
464
465static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
466 struct vscsibk_pend *pending_req)
467{
468 u32 flags;
469 int i, err, n_segs, i_seg = 0;
470 struct page **pg;
471 struct scsiif_request_segment *seg;
472 unsigned long end_seg = 0;
473 unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
474 unsigned int nr_sgl = 0;
475 struct scatterlist *sg;
476 grant_handle_t *grant;
477
478 pending_req->n_sg = 0;
479 pending_req->n_grants = 0;
480 pending_req->data_len = 0;
481
482 nr_segments &= ~VSCSIIF_SG_GRANT;
483 if (!nr_segments)
484 return 0;
485
486 if (nr_segments > VSCSIIF_SG_TABLESIZE) {
78574878 487 pr_debug("invalid parameter nr_seg = %d\n",
d9d660f6
JG		 488 ring_req->nr_segments);
489 return -EINVAL;
490 }
491
492 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
493 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
494 pending_req->pages, pending_req->grant_handles,
495 nr_segments, GNTMAP_host_map | GNTMAP_readonly);
496 if (err)
497 return err;
498 nr_sgl = nr_segments;
499 nr_segments = 0;
500 for (i = 0; i < nr_sgl; i++) {
501 n_segs = ring_req->seg[i].length /
502 sizeof(struct scsiif_request_segment);
503 if ((unsigned)ring_req->seg[i].offset +
504 (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
505 n_segs * sizeof(struct scsiif_request_segment) !=
506 ring_req->seg[i].length)
507 return -EINVAL;
508 nr_segments += n_segs;
509 }
510 if (nr_segments > SG_ALL) {
78574878 511 pr_debug("invalid nr_seg = %d\n", nr_segments);
d9d660f6
JG		 512 return -EINVAL;
513 }
514 }
515
78574878 516 /* free of (sgl) in fast_flush_area() */
d9d660f6
JG		 517 pending_req->sgl = kmalloc_array(nr_segments,
518 sizeof(struct scatterlist), GFP_KERNEL);
519 if (!pending_req->sgl)
520 return -ENOMEM;
521
522 sg_init_table(pending_req->sgl, nr_segments);
523 pending_req->n_sg = nr_segments;
524
525 flags = GNTMAP_host_map;
526 if (pending_req->sc_data_direction == DMA_TO_DEVICE)
527 flags |= GNTMAP_readonly;
528
529 pg = pending_req->pages + nr_sgl;
530 grant = pending_req->grant_handles + nr_sgl;
531 if (!nr_sgl) {
532 seg = ring_req->seg;
533 err = scsiback_gnttab_data_map_list(pending_req, seg,
534 pg, grant, nr_segments, flags);
535 if (err)
536 return err;
537 } else {
538 for (i = 0; i < nr_sgl; i++) {
539 seg = (struct scsiif_request_segment *)(
540 vaddr(pending_req, i) + ring_req->seg[i].offset);
541 n_segs = ring_req->seg[i].length /
542 sizeof(struct scsiif_request_segment);
543 err = scsiback_gnttab_data_map_list(pending_req, seg,
544 pg, grant, n_segs, flags);
545 if (err)
546 return err;
547 pg += n_segs;
548 grant += n_segs;
549 }
550 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
551 seg = (struct scsiif_request_segment *)end_seg;
552 end_seg += ring_req->seg[0].length;
553 pg = pending_req->pages + nr_sgl;
554 }
555
556 for_each_sg(pending_req->sgl, sg, nr_segments, i) {
557 sg_set_page(sg, pg[i], seg->length, seg->offset);
558 pending_req->data_len += seg->length;
559 seg++;
560 if (nr_sgl && (unsigned long)seg >= end_seg) {
561 i_seg++;
562 end_seg = vaddr(pending_req, i_seg) +
563 ring_req->seg[i_seg].offset;
564 seg = (struct scsiif_request_segment *)end_seg;
565 end_seg += ring_req->seg[i_seg].length;
566 }
567 if (sg->offset >= PAGE_SIZE ||
568 sg->length > PAGE_SIZE ||
569 sg->offset + sg->length > PAGE_SIZE)
570 return -EINVAL;
571 }
572
573 return 0;
574}
575
576static void scsiback_disconnect(struct vscsibk_info *info)
577{
578 wait_event(info->waiting_to_free,
579 atomic_read(&info->nr_unreplied_reqs) == 0);
580
581 unbind_from_irqhandler(info->irq, info);
582 info->irq = 0;
583 xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
584}
585
586static void scsiback_device_action(struct vscsibk_pend *pending_req,
587 enum tcm_tmreq_table act, int tag)
588{
589 int rc, err = FAILED;
590 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
591 struct se_cmd *se_cmd = &pending_req->se_cmd;
592 struct scsiback_tmr *tmr;
593
594 tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
595 if (!tmr)
596 goto out;
597
598 init_waitqueue_head(&tmr->tmr_wait);
599
600 transport_init_se_cmd(se_cmd, tpg->se_tpg.se_tpg_tfo,
68d81f40 601 tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, TCM_SIMPLE_TAG,
d9d660f6
JG		 602 &pending_req->sense_buffer[0]);
603
604 rc = core_tmr_alloc_req(se_cmd, tmr, act, GFP_KERNEL);
605 if (rc < 0)
606 goto out;
607
608 se_cmd->se_tmr_req->ref_task_tag = tag;
609
610 if (transport_lookup_tmr_lun(se_cmd, pending_req->v2p->lun) < 0)
611 goto out;
612
613 transport_generic_handle_tmr(se_cmd);
614 wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
615
616 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
617 SUCCESS : FAILED;
618
619out:
620 if (tmr) {
621 transport_generic_free_cmd(&pending_req->se_cmd, 1);
622 kfree(tmr);
623 }
624
625 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
626
627 kmem_cache_free(scsiback_cachep, pending_req);
628}
629
630/*
631 Perform virtual to physical translation
632*/
633static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
634 struct ids_tuple *v)
635{
636 struct v2p_entry *entry;
637 struct list_head *head = &(info->v2p_entry_lists);
638 unsigned long flags;
639
640 spin_lock_irqsave(&info->v2p_lock, flags);
641 list_for_each_entry(entry, head, l) {
642 if ((entry->v.chn == v->chn) &&
643 (entry->v.tgt == v->tgt) &&
644 (entry->v.lun == v->lun)) {
645 kref_get(&entry->kref);
646 goto out;
647 }
648 }
649 entry = NULL;
650
651out:
652 spin_unlock_irqrestore(&info->v2p_lock, flags);
653 return entry;
654}
655
656static int prepare_pending_reqs(struct vscsibk_info *info,
657 struct vscsiif_request *ring_req,
658 struct vscsibk_pend *pending_req)
659{
660 struct v2p_entry *v2p;
661 struct ids_tuple vir;
662
663 pending_req->rqid = ring_req->rqid;
664 pending_req->info = info;
665
666 vir.chn = ring_req->channel;
667 vir.tgt = ring_req->id;
668 vir.lun = ring_req->lun;
669
670 v2p = scsiback_do_translation(info, &vir);
671 if (!v2p) {
672 pending_req->v2p = NULL;
78574878
TC		 673 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
674 vir.chn, vir.tgt, vir.lun);
d9d660f6
JG		 675 return -ENODEV;
676 }
677 pending_req->v2p = v2p;
678
679 /* request range check from frontend */
680 pending_req->sc_data_direction = ring_req->sc_data_direction;
681 if ((pending_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
682 (pending_req->sc_data_direction != DMA_TO_DEVICE) &&
683 (pending_req->sc_data_direction != DMA_FROM_DEVICE) &&
684 (pending_req->sc_data_direction != DMA_NONE)) {
78574878 685 pr_debug("invalid parameter data_dir = %d\n",
d9d660f6
JG		 686 pending_req->sc_data_direction);
687 return -EINVAL;
688 }
689
690 pending_req->cmd_len = ring_req->cmd_len;
691 if (pending_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
78574878 692 pr_debug("invalid parameter cmd_len = %d\n",
d9d660f6
JG		 693 pending_req->cmd_len);
694 return -EINVAL;
695 }
696 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
697
698 return 0;
699}
700
701static int scsiback_do_cmd_fn(struct vscsibk_info *info)
702{
703 struct vscsiif_back_ring *ring = &info->ring;
facb5732 704 struct vscsiif_request ring_req;
d9d660f6
JG		 705 struct vscsibk_pend *pending_req;
706 RING_IDX rc, rp;
707 int err, more_to_do;
708 uint32_t result;
d9d660f6
JG		 709
710 rc = ring->req_cons;
711 rp = ring->sring->req_prod;
712 rmb(); /* guest system is accessing ring, too */
713
714 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
715 rc = ring->rsp_prod_pvt;
78574878 716 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
d9d660f6
JG		 717 info->domid, rp, rc, rp - rc);
718 info->ring_error = 1;
719 return 0;
720 }
721
722 while ((rc != rp)) {
723 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
724 break;
725 pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL);
726 if (!pending_req)
727 return 1;
728
be69746e 729 RING_COPY_REQUEST(ring, rc, &ring_req);
d9d660f6
JG		 730 ring->req_cons = ++rc;
731
facb5732 732 err = prepare_pending_reqs(info, &ring_req, pending_req);
d9d660f6
JG		 733 if (err) {
734 switch (err) {
735 case -ENODEV:
736 result = DID_NO_CONNECT;
737 break;
738 default:
739 result = DRIVER_ERROR;
740 break;
741 }
742 scsiback_do_resp_with_sense(NULL, result << 24, 0,
743 pending_req);
744 kmem_cache_free(scsiback_cachep, pending_req);
745 return 1;
746 }
747
facb5732 748 switch (ring_req.act) {
d9d660f6 749 case VSCSIIF_ACT_SCSI_CDB:
facb5732 750 if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
d9d660f6
JG		 751 scsiback_fast_flush_area(pending_req);
752 scsiback_do_resp_with_sense(NULL,
753 DRIVER_ERROR << 24, 0, pending_req);
754 kmem_cache_free(scsiback_cachep, pending_req);
755 } else {
756 scsiback_cmd_exec(pending_req);
757 }
758 break;
759 case VSCSIIF_ACT_SCSI_ABORT:
760 scsiback_device_action(pending_req, TMR_ABORT_TASK,
facb5732 761 ring_req.ref_rqid);
d9d660f6
JG		 762 break;
763 case VSCSIIF_ACT_SCSI_RESET:
764 scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
765 break;
766 default:
78574878 767 pr_err_ratelimited("invalid request\n");
d9d660f6
JG		 768 scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24,
769 0, pending_req);
770 kmem_cache_free(scsiback_cachep, pending_req);
771 break;
772 }
773
774 /* Yield point for this unbounded loop. */
775 cond_resched();
776 }
777
778 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
779 return more_to_do;
780}
781
782static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
783{
784 struct vscsibk_info *info = dev_id;
785
786 if (info->ring_error)
787 return IRQ_HANDLED;
788
789 while (scsiback_do_cmd_fn(info))
790 cond_resched();
791
792 return IRQ_HANDLED;
793}
794
795static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
796 evtchn_port_t evtchn)
797{
798 void *area;
799 struct vscsiif_sring *sring;
800 int err;
801
802 if (info->irq)
803 return -1;
804
ccc9d90a 805 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
d9d660f6
JG		 806 if (err)
807 return err;
808
809 sring = (struct vscsiif_sring *)area;
810 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
811
812 err = bind_interdomain_evtchn_to_irq(info->domid, evtchn);
813 if (err < 0)
814 goto unmap_page;
815
816 info->irq = err;
817
818 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
819 IRQF_ONESHOT, "vscsiif-backend", info);
820 if (err)
821 goto free_irq;
822
823 return 0;
824
825free_irq:
826 unbind_from_irqhandler(info->irq, info);
827 info->irq = 0;
828unmap_page:
829 xenbus_unmap_ring_vfree(info->dev, area);
830
831 return err;
832}
833
834static int scsiback_map(struct vscsibk_info *info)
835{
836 struct xenbus_device *dev = info->dev;
837 unsigned int ring_ref, evtchn;
838 int err;
839
840 err = xenbus_gather(XBT_NIL, dev->otherend,
841 "ring-ref", "%u", &ring_ref,
842 "event-channel", "%u", &evtchn, NULL);
843 if (err) {
844 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
845 return err;
846 }
847
848 return scsiback_init_sring(info, ring_ref, evtchn);
849}
850
c9e2f531
JG		 851/*
852 Check for a translation entry being present
853*/
854static struct v2p_entry *scsiback_chk_translation_entry(
855 struct vscsibk_info *info, struct ids_tuple *v)
856{
857 struct list_head *head = &(info->v2p_entry_lists);
858 struct v2p_entry *entry;
859
860 list_for_each_entry(entry, head, l)
861 if ((entry->v.chn == v->chn) &&
862 (entry->v.tgt == v->tgt) &&
863 (entry->v.lun == v->lun))
864 return entry;
865
866 return NULL;
867}
868
d9d660f6
JG		 869/*
870 Add a new translation entry
871*/
872static int scsiback_add_translation_entry(struct vscsibk_info *info,
873 char *phy, struct ids_tuple *v)
874{
875 int err = 0;
d9d660f6 876 struct v2p_entry *new;
d9d660f6
JG		 877 unsigned long flags;
878 char *lunp;
196e2e2a 879 unsigned long long unpacked_lun;
6bb82612 880 struct se_lun *se_lun;
d9d660f6
JG		 881 struct scsiback_tpg *tpg_entry, *tpg = NULL;
882 char *error = "doesn't exist";
883
884 lunp = strrchr(phy, ':');
885 if (!lunp) {
78574878 886 pr_err("illegal format of physical device %s\n", phy);
d9d660f6
JG		 887 return -EINVAL;
888 }
889 *lunp = 0;
890 lunp++;
196e2e2a
HR		 891 err = kstrtoull(lunp, 10, &unpacked_lun);
892 if (err < 0) {
78574878 893 pr_err("lun number not valid: %s\n", lunp);
196e2e2a 894 return err;
d9d660f6
JG		 895 }
896
897 mutex_lock(&scsiback_mutex);
898 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
899 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
900 !strcmp(phy, tpg_entry->param_alias)) {
6bb82612
NB		 901 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex);
902 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) {
903 if (se_lun->unpacked_lun == unpacked_lun) {
904 if (!tpg_entry->tpg_nexus)
905 error = "nexus undefined";
906 else
907 tpg = tpg_entry;
908 break;
909 }
d9d660f6 910 }
6bb82612 911 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex);
d9d660f6
JG		 912 break;
913 }
914 }
915 if (tpg) {
916 mutex_lock(&tpg->tv_tpg_mutex);
917 tpg->tv_tpg_fe_count++;
918 mutex_unlock(&tpg->tv_tpg_mutex);
919 }
920 mutex_unlock(&scsiback_mutex);
921
922 if (!tpg) {
0fb1f14e 923 pr_err("%s:%llu %s\n", phy, unpacked_lun, error);
d9d660f6
JG		 924 return -ENODEV;
925 }
926
927 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
928 if (new == NULL) {
929 err = -ENOMEM;
930 goto out_free;
931 }
932
933 spin_lock_irqsave(&info->v2p_lock, flags);
934
935 /* Check double assignment to identical virtual ID */
c9e2f531
JG		 936 if (scsiback_chk_translation_entry(info, v)) {
937 pr_warn("Virtual ID is already used. Assignment was not performed.\n");
938 err = -EEXIST;
939 goto out;
d9d660f6
JG		 940 }
941
942 /* Create a new translation entry and add to the list */
943 kref_init(&new->kref);
944 new->v = *v;
945 new->tpg = tpg;
6bb82612 946 new->lun = unpacked_lun;
c9e2f531 947 list_add_tail(&new->l, &info->v2p_entry_lists);
d9d660f6
JG		 948
949out:
950 spin_unlock_irqrestore(&info->v2p_lock, flags);
951
952out_free:
f285aa8d
JG		 953 if (err) {
954 mutex_lock(&tpg->tv_tpg_mutex);
955 tpg->tv_tpg_fe_count--;
956 mutex_unlock(&tpg->tv_tpg_mutex);
d9d660f6 957 kfree(new);
f285aa8d 958 }
d9d660f6
JG		 959
960 return err;
961}
962
963static void __scsiback_del_translation_entry(struct v2p_entry *entry)
964{
965 list_del(&entry->l);
966 kref_put(&entry->kref, scsiback_free_translation_entry);
967}
968
969/*
c9e2f531 970 Delete the translation entry specified
d9d660f6
JG		 971*/
972static int scsiback_del_translation_entry(struct vscsibk_info *info,
973 struct ids_tuple *v)
974{
975 struct v2p_entry *entry;
d9d660f6 976 unsigned long flags;
c9e2f531 977 int ret = 0;
d9d660f6
JG		 978
979 spin_lock_irqsave(&info->v2p_lock, flags);
980 /* Find out the translation entry specified */
c9e2f531
JG		 981 entry = scsiback_chk_translation_entry(info, v);
982 if (entry)
983 __scsiback_del_translation_entry(entry);
984 else
985 ret = -ENOENT;
d9d660f6
JG		 986
987 spin_unlock_irqrestore(&info->v2p_lock, flags);
c9e2f531 988 return ret;
d9d660f6
JG		 989}
990
991static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
169e6cf0 992 char *phy, struct ids_tuple *vir, int try)
d9d660f6 993{
c9e2f531
JG		 994 struct v2p_entry *entry;
995 unsigned long flags;
996
997 if (try) {
998 spin_lock_irqsave(&info->v2p_lock, flags);
999 entry = scsiback_chk_translation_entry(info, vir);
1000 spin_unlock_irqrestore(&info->v2p_lock, flags);
1001 if (entry)
1002 return;
1003 }
d9d660f6
JG		 1004 if (!scsiback_add_translation_entry(info, phy, vir)) {
1005 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1006 "%d", XenbusStateInitialised)) {
78574878 1007 pr_err("xenbus_printf error %s\n", state);
d9d660f6
JG		 1008 scsiback_del_translation_entry(info, vir);
1009 }
169e6cf0 1010 } else if (!try) {
d9d660f6
JG		 1011 xenbus_printf(XBT_NIL, info->dev->nodename, state,
1012 "%d", XenbusStateClosed);
1013 }
1014}
1015
1016static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1017 struct ids_tuple *vir)
1018{
1019 if (!scsiback_del_translation_entry(info, vir)) {
1020 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1021 "%d", XenbusStateClosed))
78574878 1022 pr_err("xenbus_printf error %s\n", state);
d9d660f6
JG		 1023 }
1024}
1025
1026#define VSCSIBACK_OP_ADD_OR_DEL_LUN 1
1027#define VSCSIBACK_OP_UPDATEDEV_STATE 2
1028
1029static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1030 char *ent)
1031{
1032 int err;
1033 struct ids_tuple vir;
1034 char *val;
1035 int device_state;
1036 char phy[VSCSI_NAMELEN];
1037 char str[64];
1038 char state[64];
1039 struct xenbus_device *dev = info->dev;
1040
1041 /* read status */
1042 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1043 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1044 if (XENBUS_EXIST_ERR(err))
1045 return;
1046
1047 /* physical SCSI device */
1048 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1049 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1050 if (IS_ERR(val)) {
1051 xenbus_printf(XBT_NIL, dev->nodename, state,
1052 "%d", XenbusStateClosed);
1053 return;
1054 }
1055 strlcpy(phy, val, VSCSI_NAMELEN);
1056 kfree(val);
1057
1058 /* virtual SCSI device */
1059 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1060 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1061 &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1062 if (XENBUS_EXIST_ERR(err)) {
1063 xenbus_printf(XBT_NIL, dev->nodename, state,
1064 "%d", XenbusStateClosed);
1065 return;
1066 }
1067
1068 switch (op) {
1069 case VSCSIBACK_OP_ADD_OR_DEL_LUN:
169e6cf0
JG		 1070 switch (device_state) {
1071 case XenbusStateInitialising:
1072 scsiback_do_add_lun(info, state, phy, &vir, 0);
1073 break;
1074 case XenbusStateConnected:
1075 scsiback_do_add_lun(info, state, phy, &vir, 1);
1076 break;
1077 case XenbusStateClosing:
d9d660f6 1078 scsiback_do_del_lun(info, state, &vir);
169e6cf0
JG		 1079 break;
1080 default:
1081 break;
1082 }
d9d660f6
JG		 1083 break;
1084
1085 case VSCSIBACK_OP_UPDATEDEV_STATE:
1086 if (device_state == XenbusStateInitialised) {
1087 /* modify vscsi-devs/dev-x/state */
1088 if (xenbus_printf(XBT_NIL, dev->nodename, state,
1089 "%d", XenbusStateConnected)) {
78574878 1090 pr_err("xenbus_printf error %s\n", str);
d9d660f6
JG		 1091 scsiback_del_translation_entry(info, &vir);
1092 xenbus_printf(XBT_NIL, dev->nodename, state,
1093 "%d", XenbusStateClosed);
1094 }
1095 }
1096 break;
78574878 1097 /* When it is necessary, processing is added here. */
d9d660f6
JG		 1098 default:
1099 break;
1100 }
1101}
1102
1103static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1104{
1105 int i;
1106 char **dir;
1107 unsigned int ndir = 0;
1108
1109 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1110 &ndir);
1111 if (IS_ERR(dir))
1112 return;
1113
1114 for (i = 0; i < ndir; i++)
1115 scsiback_do_1lun_hotplug(info, op, dir[i]);
1116
1117 kfree(dir);
1118}
1119
1120static void scsiback_frontend_changed(struct xenbus_device *dev,
1121 enum xenbus_state frontend_state)
1122{
1123 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1124
1125 switch (frontend_state) {
1126 case XenbusStateInitialising:
1127 break;
1128
1129 case XenbusStateInitialised:
1130 if (scsiback_map(info))
1131 break;
1132
1133 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1134 xenbus_switch_state(dev, XenbusStateConnected);
1135 break;
1136
1137 case XenbusStateConnected:
1138 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1139
1140 if (dev->state == XenbusStateConnected)
1141 break;
1142
1143 xenbus_switch_state(dev, XenbusStateConnected);
1144 break;
1145
1146 case XenbusStateClosing:
1147 if (info->irq)
1148 scsiback_disconnect(info);
1149
1150 xenbus_switch_state(dev, XenbusStateClosing);
1151 break;
1152
1153 case XenbusStateClosed:
1154 xenbus_switch_state(dev, XenbusStateClosed);
1155 if (xenbus_dev_is_online(dev))
1156 break;
1157 /* fall through if not online */
1158 case XenbusStateUnknown:
1159 device_unregister(&dev->dev);
1160 break;
1161
1162 case XenbusStateReconfiguring:
1163 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1164 xenbus_switch_state(dev, XenbusStateReconfigured);
1165
1166 break;
1167
1168 default:
1169 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1170 frontend_state);
1171 break;
1172 }
1173}
1174
1175/*
1176 Release the translation entry specfied
1177*/
1178static void scsiback_release_translation_entry(struct vscsibk_info *info)
1179{
1180 struct v2p_entry *entry, *tmp;
1181 struct list_head *head = &(info->v2p_entry_lists);
1182 unsigned long flags;
1183
1184 spin_lock_irqsave(&info->v2p_lock, flags);
1185
1186 list_for_each_entry_safe(entry, tmp, head, l)
1187 __scsiback_del_translation_entry(entry);
1188
1189 spin_unlock_irqrestore(&info->v2p_lock, flags);
1190}
1191
1192static int scsiback_remove(struct xenbus_device *dev)
1193{
1194 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1195
1196 if (info->irq)
1197 scsiback_disconnect(info);
1198
1199 scsiback_release_translation_entry(info);
1200
1201 dev_set_drvdata(&dev->dev, NULL);
1202
1203 return 0;
1204}
1205
1206static int scsiback_probe(struct xenbus_device *dev,
1207 const struct xenbus_device_id *id)
1208{
1209 int err;
1210
1211 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1212 GFP_KERNEL);
1213
78574878 1214 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
d9d660f6
JG		 1215
1216 if (!info) {
1217 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1218 return -ENOMEM;
1219 }
1220 info->dev = dev;
1221 dev_set_drvdata(&dev->dev, info);
1222
1223 info->domid = dev->otherend_id;
1224 spin_lock_init(&info->ring_lock);
1225 info->ring_error = 0;
1226 atomic_set(&info->nr_unreplied_reqs, 0);
1227 init_waitqueue_head(&info->waiting_to_free);
1228 info->dev = dev;
1229 info->irq = 0;
1230 INIT_LIST_HEAD(&info->v2p_entry_lists);
1231 spin_lock_init(&info->v2p_lock);
1232
1233 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1234 SG_ALL);
1235 if (err)
1236 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1237
1238 err = xenbus_switch_state(dev, XenbusStateInitWait);
1239 if (err)
1240 goto fail;
1241
1242 return 0;
1243
1244fail:
78574878 1245 pr_warn("%s failed\n", __func__);
d9d660f6
JG		 1246 scsiback_remove(dev);
1247
1248 return err;
1249}
1250
1251static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1252{
1253 switch (tport->tport_proto_id) {
1254 case SCSI_PROTOCOL_SAS:
1255 return "SAS";
1256 case SCSI_PROTOCOL_FCP:
1257 return "FCP";
1258 case SCSI_PROTOCOL_ISCSI:
1259 return "iSCSI";
1260 default:
1261 break;
1262 }
1263
1264 return "Unknown";
1265}
1266
d9d660f6
JG		 1267static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1268{
1269 struct scsiback_tpg *tpg = container_of(se_tpg,
1270 struct scsiback_tpg, se_tpg);
1271 struct scsiback_tport *tport = tpg->tport;
1272
1273 return &tport->tport_name[0];
1274}
1275
1276static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1277{
1278 struct scsiback_tpg *tpg = container_of(se_tpg,
1279 struct scsiback_tpg, se_tpg);
1280 return tpg->tport_tpgt;
1281}
1282
d9d660f6
JG		 1283static struct se_wwn *
1284scsiback_make_tport(struct target_fabric_configfs *tf,
1285 struct config_group *group,
1286 const char *name)
1287{
1288 struct scsiback_tport *tport;
1289 char *ptr;
1290 u64 wwpn = 0;
1291 int off = 0;
1292
1293 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1294 if (!tport)
1295 return ERR_PTR(-ENOMEM);
1296
1297 tport->tport_wwpn = wwpn;
1298 /*
1299 * Determine the emulated Protocol Identifier and Target Port Name
1300 * based on the incoming configfs directory name.
1301 */
1302 ptr = strstr(name, "naa.");
1303 if (ptr) {
1304 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1305 goto check_len;
1306 }
1307 ptr = strstr(name, "fc.");
1308 if (ptr) {
1309 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1310 off = 3; /* Skip over "fc." */
1311 goto check_len;
1312 }
1313 ptr = strstr(name, "iqn.");
1314 if (ptr) {
1315 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1316 goto check_len;
1317 }
1318
1319 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1320 kfree(tport);
1321 return ERR_PTR(-EINVAL);
1322
1323check_len:
1324 if (strlen(name) >= VSCSI_NAMELEN) {
1325 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1326 scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1327 kfree(tport);
1328 return ERR_PTR(-EINVAL);
1329 }
1330 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1331
78574878 1332 pr_debug("Allocated emulated Target %s Address: %s\n",
d9d660f6
JG		 1333 scsiback_dump_proto_id(tport), name);
1334
1335 return &tport->tport_wwn;
1336}
1337
1338static void scsiback_drop_tport(struct se_wwn *wwn)
1339{
1340 struct scsiback_tport *tport = container_of(wwn,
1341 struct scsiback_tport, tport_wwn);
1342
78574878 1343 pr_debug("Deallocating emulated Target %s Address: %s\n",
d9d660f6
JG		 1344 scsiback_dump_proto_id(tport), tport->tport_name);
1345
1346 kfree(tport);
1347}
1348
d9d660f6
JG		 1349static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1350{
1351 return 1;
1352}
1353
1354static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1355{
1356 /*
78574878
TC		 1357 * Do not release struct se_cmd's containing a valid TMR pointer.
1358 * These will be released directly in scsiback_device_action()
d9d660f6
JG		 1359 * with transport_generic_free_cmd().
1360 */
1361 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1362 return 0;
1363
1364 transport_generic_free_cmd(se_cmd, 0);
1365 return 1;
1366}
1367
1368static void scsiback_release_cmd(struct se_cmd *se_cmd)
1369{
1370 struct vscsibk_pend *pending_req = container_of(se_cmd,
1371 struct vscsibk_pend, se_cmd);
1372
1373 kmem_cache_free(scsiback_cachep, pending_req);
1374}
1375
1376static int scsiback_shutdown_session(struct se_session *se_sess)
1377{
1378 return 0;
1379}
1380
1381static void scsiback_close_session(struct se_session *se_sess)
1382{
1383}
1384
1385static u32 scsiback_sess_get_index(struct se_session *se_sess)
1386{
1387 return 0;
1388}
1389
1390static int scsiback_write_pending(struct se_cmd *se_cmd)
1391{
1392 /* Go ahead and process the write immediately */
1393 target_execute_cmd(se_cmd);
1394
1395 return 0;
1396}
1397
1398static int scsiback_write_pending_status(struct se_cmd *se_cmd)
1399{
1400 return 0;
1401}
1402
1403static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1404{
1405}
1406
d9d660f6
JG		 1407static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1408{
1409 return 0;
1410}
1411
1412static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1413{
1414 struct vscsibk_pend *pending_req = container_of(se_cmd,
1415 struct vscsibk_pend, se_cmd);
1416
1417 pending_req->result = SAM_STAT_GOOD;
1418 scsiback_cmd_done(pending_req);
1419 return 0;
1420}
1421
1422static int scsiback_queue_status(struct se_cmd *se_cmd)
1423{
1424 struct vscsibk_pend *pending_req = container_of(se_cmd,
1425 struct vscsibk_pend, se_cmd);
1426
1427 if (se_cmd->sense_buffer &&
1428 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1429 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1430 pending_req->result = (DRIVER_SENSE << 24) |
1431 SAM_STAT_CHECK_CONDITION;
1432 else
1433 pending_req->result = se_cmd->scsi_status;
1434
1435 scsiback_cmd_done(pending_req);
1436 return 0;
1437}
1438
1439static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1440{
1441 struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
1442 struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr;
1443
1444 atomic_set(&tmr->tmr_complete, 1);
1445 wake_up(&tmr->tmr_wait);
1446}
1447
1448static void scsiback_aborted_task(struct se_cmd *se_cmd)
1449{
1450}
1451
2eafd729 1452static ssize_t scsiback_tpg_param_alias_show(struct config_item *item,
d9d660f6
JG		 1453 char *page)
1454{
2eafd729 1455 struct se_portal_group *se_tpg = param_to_tpg(item);
d9d660f6
JG		 1456 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1457 se_tpg);
1458 ssize_t rb;
1459
1460 mutex_lock(&tpg->tv_tpg_mutex);
1461 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1462 mutex_unlock(&tpg->tv_tpg_mutex);
1463
1464 return rb;
1465}
1466
2eafd729 1467static ssize_t scsiback_tpg_param_alias_store(struct config_item *item,
d9d660f6
JG		 1468 const char *page, size_t count)
1469{
2eafd729 1470 struct se_portal_group *se_tpg = param_to_tpg(item);
d9d660f6
JG		 1471 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1472 se_tpg);
1473 int len;
1474
1475 if (strlen(page) >= VSCSI_NAMELEN) {
1476 pr_err("param alias: %s, exceeds max: %d\n", page,
1477 VSCSI_NAMELEN);
1478 return -EINVAL;
1479 }
1480
1481 mutex_lock(&tpg->tv_tpg_mutex);
1482 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1483 if (tpg->param_alias[len - 1] == '\n')
1484 tpg->param_alias[len - 1] = '\0';
1485 mutex_unlock(&tpg->tv_tpg_mutex);
1486
1487 return count;
1488}
1489
2eafd729 1490CONFIGFS_ATTR(scsiback_tpg_param_, alias);
d9d660f6
JG		 1491
1492static struct configfs_attribute *scsiback_param_attrs[] = {
2eafd729 1493 &scsiback_tpg_param_attr_alias,
d9d660f6
JG		 1494 NULL,
1495};
1496
1497static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1498 const char *name)
1499{
1500 struct se_portal_group *se_tpg;
1501 struct se_session *se_sess;
1502 struct scsiback_nexus *tv_nexus;
1503
1504 mutex_lock(&tpg->tv_tpg_mutex);
1505 if (tpg->tpg_nexus) {
1506 mutex_unlock(&tpg->tv_tpg_mutex);
1507 pr_debug("tpg->tpg_nexus already exists\n");
1508 return -EEXIST;
1509 }
1510 se_tpg = &tpg->se_tpg;
1511
1512 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1513 if (!tv_nexus) {
1514 mutex_unlock(&tpg->tv_tpg_mutex);
1515 return -ENOMEM;
1516 }
1517 /*
78574878 1518 * Initialize the struct se_session pointer
d9d660f6
JG		 1519 */
1520 tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_NORMAL);
1521 if (IS_ERR(tv_nexus->tvn_se_sess)) {
1522 mutex_unlock(&tpg->tv_tpg_mutex);
1523 kfree(tv_nexus);
1524 return -ENOMEM;
1525 }
1526 se_sess = tv_nexus->tvn_se_sess;
1527 /*
1528 * Since we are running in 'demo mode' this call with generate a
1529 * struct se_node_acl for the scsiback struct se_portal_group with
1530 * the SCSI Initiator port name of the passed configfs group 'name'.
1531 */
1532 tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1533 se_tpg, (unsigned char *)name);
1534 if (!tv_nexus->tvn_se_sess->se_node_acl) {
1535 mutex_unlock(&tpg->tv_tpg_mutex);
1536 pr_debug("core_tpg_check_initiator_node_acl() failed for %s\n",
1537 name);
1538 goto out;
1539 }
2f450cc1
BVA		 1540 /* Now register the TCM pvscsi virtual I_T Nexus as active. */
1541 transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
d9d660f6
JG		 1542 tv_nexus->tvn_se_sess, tv_nexus);
1543 tpg->tpg_nexus = tv_nexus;
1544
1545 mutex_unlock(&tpg->tv_tpg_mutex);
1546 return 0;
1547
1548out:
1549 transport_free_session(se_sess);
1550 kfree(tv_nexus);
1551 return -ENOMEM;
1552}
1553
1554static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1555{
1556 struct se_session *se_sess;
1557 struct scsiback_nexus *tv_nexus;
1558
1559 mutex_lock(&tpg->tv_tpg_mutex);
1560 tv_nexus = tpg->tpg_nexus;
1561 if (!tv_nexus) {
1562 mutex_unlock(&tpg->tv_tpg_mutex);
1563 return -ENODEV;
1564 }
1565
1566 se_sess = tv_nexus->tvn_se_sess;
1567 if (!se_sess) {
1568 mutex_unlock(&tpg->tv_tpg_mutex);
1569 return -ENODEV;
1570 }
1571
1572 if (tpg->tv_tpg_port_count != 0) {
1573 mutex_unlock(&tpg->tv_tpg_mutex);
1574 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1575 tpg->tv_tpg_port_count);
1576 return -EBUSY;
1577 }
1578
1579 if (tpg->tv_tpg_fe_count != 0) {
1580 mutex_unlock(&tpg->tv_tpg_mutex);
1581 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1582 tpg->tv_tpg_fe_count);
1583 return -EBUSY;
1584 }
1585
78574878 1586 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n",
d9d660f6
JG		 1587 scsiback_dump_proto_id(tpg->tport),
1588 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1589
1590 /*
1591 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1592 */
1593 transport_deregister_session(tv_nexus->tvn_se_sess);
1594 tpg->tpg_nexus = NULL;
1595 mutex_unlock(&tpg->tv_tpg_mutex);
1596
1597 kfree(tv_nexus);
1598 return 0;
1599}
1600
2eafd729 1601static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page)
d9d660f6 1602{
2eafd729 1603 struct se_portal_group *se_tpg = to_tpg(item);
d9d660f6
JG		 1604 struct scsiback_tpg *tpg = container_of(se_tpg,
1605 struct scsiback_tpg, se_tpg);
1606 struct scsiback_nexus *tv_nexus;
1607 ssize_t ret;
1608
1609 mutex_lock(&tpg->tv_tpg_mutex);
1610 tv_nexus = tpg->tpg_nexus;
1611 if (!tv_nexus) {
1612 mutex_unlock(&tpg->tv_tpg_mutex);
1613 return -ENODEV;
1614 }
1615 ret = snprintf(page, PAGE_SIZE, "%s\n",
1616 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1617 mutex_unlock(&tpg->tv_tpg_mutex);
1618
1619 return ret;
1620}
1621
2eafd729
CH		 1622static ssize_t scsiback_tpg_nexus_store(struct config_item *item,
1623 const char *page, size_t count)
d9d660f6 1624{
2eafd729 1625 struct se_portal_group *se_tpg = to_tpg(item);
d9d660f6
JG		 1626 struct scsiback_tpg *tpg = container_of(se_tpg,
1627 struct scsiback_tpg, se_tpg);
1628 struct scsiback_tport *tport_wwn = tpg->tport;
1629 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1630 int ret;
1631 /*
78574878 1632 * Shutdown the active I_T nexus if 'NULL' is passed.
d9d660f6
JG		 1633 */
1634 if (!strncmp(page, "NULL", 4)) {
1635 ret = scsiback_drop_nexus(tpg);
1636 return (!ret) ? count : ret;
1637 }
1638 /*
1639 * Otherwise make sure the passed virtual Initiator port WWN matches
1640 * the fabric protocol_id set in scsiback_make_tport(), and call
1641 * scsiback_make_nexus().
1642 */
1643 if (strlen(page) >= VSCSI_NAMELEN) {
1644 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1645 page, VSCSI_NAMELEN);
1646 return -EINVAL;
1647 }
1648 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1649
1650 ptr = strstr(i_port, "naa.");
1651 if (ptr) {
1652 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1653 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1654 i_port, scsiback_dump_proto_id(tport_wwn));
1655 return -EINVAL;
1656 }
1657 port_ptr = &i_port[0];
1658 goto check_newline;
1659 }
1660 ptr = strstr(i_port, "fc.");
1661 if (ptr) {
1662 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1663 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1664 i_port, scsiback_dump_proto_id(tport_wwn));
1665 return -EINVAL;
1666 }
1667 port_ptr = &i_port[3]; /* Skip over "fc." */
1668 goto check_newline;
1669 }
1670 ptr = strstr(i_port, "iqn.");
1671 if (ptr) {
1672 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1673 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1674 i_port, scsiback_dump_proto_id(tport_wwn));
1675 return -EINVAL;
1676 }
1677 port_ptr = &i_port[0];
1678 goto check_newline;
1679 }
1680 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1681 i_port);
1682 return -EINVAL;
1683 /*
1684 * Clear any trailing newline for the NAA WWN
1685 */
1686check_newline:
1687 if (i_port[strlen(i_port) - 1] == '\n')
1688 i_port[strlen(i_port) - 1] = '\0';
1689
1690 ret = scsiback_make_nexus(tpg, port_ptr);
1691 if (ret < 0)
1692 return ret;
1693
1694 return count;
1695}
1696
2eafd729 1697CONFIGFS_ATTR(scsiback_tpg_, nexus);
d9d660f6
JG		 1698
1699static struct configfs_attribute *scsiback_tpg_attrs[] = {
2eafd729 1700 &scsiback_tpg_attr_nexus,
d9d660f6
JG		 1701 NULL,
1702};
1703
1704static ssize_t
2eafd729 1705scsiback_wwn_version_show(struct config_item *item, char *page)
d9d660f6
JG		 1706{
1707 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1708 UTS_RELEASE"\n",
1709 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1710}
1711
2eafd729 1712CONFIGFS_ATTR_RO(scsiback_wwn_, version);
d9d660f6
JG		 1713
1714static struct configfs_attribute *scsiback_wwn_attrs[] = {
2eafd729 1715 &scsiback_wwn_attr_version,
d9d660f6
JG		 1716 NULL,
1717};
1718
1719static char *scsiback_get_fabric_name(void)
1720{
1721 return "xen-pvscsi";
1722}
1723
1724static int scsiback_port_link(struct se_portal_group *se_tpg,
1725 struct se_lun *lun)
1726{
1727 struct scsiback_tpg *tpg = container_of(se_tpg,
1728 struct scsiback_tpg, se_tpg);
1729
1730 mutex_lock(&tpg->tv_tpg_mutex);
1731 tpg->tv_tpg_port_count++;
1732 mutex_unlock(&tpg->tv_tpg_mutex);
1733
1734 return 0;
1735}
1736
1737static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1738 struct se_lun *lun)
1739{
1740 struct scsiback_tpg *tpg = container_of(se_tpg,
1741 struct scsiback_tpg, se_tpg);
1742
1743 mutex_lock(&tpg->tv_tpg_mutex);
1744 tpg->tv_tpg_port_count--;
1745 mutex_unlock(&tpg->tv_tpg_mutex);
1746}
1747
1748static struct se_portal_group *
1749scsiback_make_tpg(struct se_wwn *wwn,
1750 struct config_group *group,
1751 const char *name)
1752{
1753 struct scsiback_tport *tport = container_of(wwn,
1754 struct scsiback_tport, tport_wwn);
1755
1756 struct scsiback_tpg *tpg;
495daef9 1757 u16 tpgt;
d9d660f6
JG		 1758 int ret;
1759
1760 if (strstr(name, "tpgt_") != name)
1761 return ERR_PTR(-EINVAL);
495daef9
DC		 1762 ret = kstrtou16(name + 5, 10, &tpgt);
1763 if (ret)
1764 return ERR_PTR(ret);
d9d660f6
JG		 1765
1766 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1767 if (!tpg)
1768 return ERR_PTR(-ENOMEM);
1769
1770 mutex_init(&tpg->tv_tpg_mutex);
1771 INIT_LIST_HEAD(&tpg->tv_tpg_list);
1772 INIT_LIST_HEAD(&tpg->info_list);
1773 tpg->tport = tport;
1774 tpg->tport_tpgt = tpgt;
1775
bc0c94b1 1776 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
d9d660f6
JG		 1777 if (ret < 0) {
1778 kfree(tpg);
1779 return NULL;
1780 }
1781 mutex_lock(&scsiback_mutex);
1782 list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1783 mutex_unlock(&scsiback_mutex);
1784
1785 return &tpg->se_tpg;
1786}
1787
1788static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1789{
1790 struct scsiback_tpg *tpg = container_of(se_tpg,
1791 struct scsiback_tpg, se_tpg);
1792
1793 mutex_lock(&scsiback_mutex);
1794 list_del(&tpg->tv_tpg_list);
1795 mutex_unlock(&scsiback_mutex);
1796 /*
1797 * Release the virtual I_T Nexus for this xen-pvscsi TPG
1798 */
1799 scsiback_drop_nexus(tpg);
1800 /*
78574878 1801 * Deregister the se_tpg from TCM.
d9d660f6
JG		 1802 */
1803 core_tpg_deregister(se_tpg);
1804 kfree(tpg);
1805}
1806
1807static int scsiback_check_true(struct se_portal_group *se_tpg)
1808{
1809 return 1;
1810}
1811
1812static int scsiback_check_false(struct se_portal_group *se_tpg)
1813{
1814 return 0;
1815}
1816
9ac8928e
CH		 1817static const struct target_core_fabric_ops scsiback_ops = {
1818 .module = THIS_MODULE,
1819 .name = "xen-pvscsi",
d9d660f6 1820 .get_fabric_name = scsiback_get_fabric_name,
d9d660f6
JG		 1821 .tpg_get_wwn = scsiback_get_fabric_wwn,
1822 .tpg_get_tag = scsiback_get_tag,
d9d660f6
JG		 1823 .tpg_check_demo_mode = scsiback_check_true,
1824 .tpg_check_demo_mode_cache = scsiback_check_true,
1825 .tpg_check_demo_mode_write_protect = scsiback_check_false,
1826 .tpg_check_prod_mode_write_protect = scsiback_check_false,
d9d660f6
JG		 1827 .tpg_get_inst_index = scsiback_tpg_get_inst_index,
1828 .check_stop_free = scsiback_check_stop_free,
1829 .release_cmd = scsiback_release_cmd,
d9d660f6
JG		 1830 .shutdown_session = scsiback_shutdown_session,
1831 .close_session = scsiback_close_session,
1832 .sess_get_index = scsiback_sess_get_index,
1833 .sess_get_initiator_sid = NULL,
1834 .write_pending = scsiback_write_pending,
1835 .write_pending_status = scsiback_write_pending_status,
1836 .set_default_node_attributes = scsiback_set_default_node_attrs,
d9d660f6
JG		 1837 .get_cmd_state = scsiback_get_cmd_state,
1838 .queue_data_in = scsiback_queue_data_in,
1839 .queue_status = scsiback_queue_status,
1840 .queue_tm_rsp = scsiback_queue_tm_rsp,
1841 .aborted_task = scsiback_aborted_task,
1842 /*
1843 * Setup callers for generic logic in target_core_fabric_configfs.c
1844 */
1845 .fabric_make_wwn = scsiback_make_tport,
1846 .fabric_drop_wwn = scsiback_drop_tport,
1847 .fabric_make_tpg = scsiback_make_tpg,
1848 .fabric_drop_tpg = scsiback_drop_tpg,
1849 .fabric_post_link = scsiback_port_link,
1850 .fabric_pre_unlink = scsiback_port_unlink,
d9d660f6 1851
9ac8928e
CH		 1852 .tfc_wwn_attrs = scsiback_wwn_attrs,
1853 .tfc_tpg_base_attrs = scsiback_tpg_attrs,
1854 .tfc_tpg_param_attrs = scsiback_param_attrs,
d9d660f6
JG		 1855};
1856
1857static const struct xenbus_device_id scsiback_ids[] = {
1858 { "vscsi" },
1859 { "" }
1860};
1861
95afae48
DV		 1862static struct xenbus_driver scsiback_driver = {
1863 .ids = scsiback_ids,
d9d660f6
JG		 1864 .probe = scsiback_probe,
1865 .remove = scsiback_remove,
1866 .otherend_changed = scsiback_frontend_changed
95afae48 1867};
d9d660f6
JG		 1868
1869static void scsiback_init_pend(void *p)
1870{
1871 struct vscsibk_pend *pend = p;
1872 int i;
1873
1874 memset(pend, 0, sizeof(*pend));
1875 for (i = 0; i < VSCSI_MAX_GRANTS; i++)
1876 pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
1877}
1878
1879static int __init scsiback_init(void)
1880{
1881 int ret;
1882
1883 if (!xen_domain())
1884 return -ENODEV;
1885
9ac8928e
CH		 1886 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
1887 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1888
d9d660f6
JG		 1889 scsiback_cachep = kmem_cache_create("vscsiif_cache",
1890 sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
1891 if (!scsiback_cachep)
1892 return -ENOMEM;
1893
1894 ret = xenbus_register_backend(&scsiback_driver);
1895 if (ret)
1896 goto out_cache_destroy;
1897
9ac8928e 1898 ret = target_register_template(&scsiback_ops);
d9d660f6
JG		 1899 if (ret)
1900 goto out_unregister_xenbus;
1901
1902 return 0;
1903
1904out_unregister_xenbus:
1905 xenbus_unregister_driver(&scsiback_driver);
1906out_cache_destroy:
1907 kmem_cache_destroy(scsiback_cachep);
78574878 1908 pr_err("%s: error %d\n", __func__, ret);
d9d660f6
JG		 1909 return ret;
1910}
1911
1912static void __exit scsiback_exit(void)
1913{
1914 struct page *page;
1915
1916 while (free_pages_num) {
1917 if (get_free_page(&page))
1918 BUG();
ff4b156f 1919 gnttab_free_pages(1, &page);
d9d660f6 1920 }
9ac8928e 1921 target_unregister_template(&scsiback_ops);
d9d660f6
JG		 1922 xenbus_unregister_driver(&scsiback_driver);
1923 kmem_cache_destroy(scsiback_cachep);
1924}
1925
1926module_init(scsiback_init);
1927module_exit(scsiback_exit);
1928
1929MODULE_DESCRIPTION("Xen SCSI backend driver");
1930MODULE_LICENSE("Dual BSD/GPL");
1931MODULE_ALIAS("xen-backend:vscsi");
1932MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
Linux 6.x block layer and io_uring tree(s)