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Linux 4.9.74
[linux/fpc-iii.git] / drivers / xen / xen-scsiback.c
blob980f328173054624a34e7e753e47c5d5b5034e71
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 #define pr_fmt(fmt) "xen-pvscsi: " fmt
35
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
52 #include <scsi/scsi_host.h> /* SG_ALL */
53
54 #include <target/target_core_base.h>
55 #include <target/target_core_fabric.h>
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
69 #define VSCSI_VERSION "v0.1"
70 #define VSCSI_NAMELEN 32
71
72 struct ids_tuple {
73 unsigned int hst; /* host */
74 unsigned int chn; /* channel */
75 unsigned int tgt; /* target */
76 unsigned int lun; /* LUN */
77 };
78
79 struct 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
87 struct 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
115 struct 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 atomic_t tmr_complete;
139 wait_queue_head_t tmr_wait;
140 };
141
142 #define VSCSI_DEFAULT_SESSION_TAGS 128
143
144 struct scsiback_nexus {
145 /* Pointer to TCM session for I_T Nexus */
146 struct se_session *tvn_se_sess;
147 };
148
149 struct 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
160 struct 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
185 static bool log_print_stat;
186 module_param(log_print_stat, bool, 0644);
187
188 static int scsiback_max_buffer_pages = 1024;
189 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
190 MODULE_PARM_DESC(max_buffer_pages,
191 "Maximum number of free pages to keep in backend buffer");
192
193 static DEFINE_SPINLOCK(free_pages_lock);
194 static int free_pages_num;
195 static LIST_HEAD(scsiback_free_pages);
196
197 /* Global spinlock to protect scsiback TPG list */
198 static DEFINE_MUTEX(scsiback_mutex);
199 static LIST_HEAD(scsiback_list);
200
201 static void scsiback_get(struct vscsibk_info *info)
202 {
203 atomic_inc(&info->nr_unreplied_reqs);
204 }
205
206 static void scsiback_put(struct vscsibk_info *info)
207 {
208 if (atomic_dec_and_test(&info->nr_unreplied_reqs))
209 wake_up(&info->waiting_to_free);
210 }
211
212 static void put_free_pages(struct page **page, int num)
213 {
214 unsigned long flags;
215 int i = free_pages_num + num, n = num;
216
217 if (num == 0)
218 return;
219 if (i > scsiback_max_buffer_pages) {
220 n = min(num, i - scsiback_max_buffer_pages);
221 gnttab_free_pages(n, page + num - n);
222 n = num - n;
223 }
224 spin_lock_irqsave(&free_pages_lock, flags);
225 for (i = 0; i < n; i++)
226 list_add(&page[i]->lru, &scsiback_free_pages);
227 free_pages_num += n;
228 spin_unlock_irqrestore(&free_pages_lock, flags);
229 }
230
231 static int get_free_page(struct page **page)
232 {
233 unsigned long flags;
234
235 spin_lock_irqsave(&free_pages_lock, flags);
236 if (list_empty(&scsiback_free_pages)) {
237 spin_unlock_irqrestore(&free_pages_lock, flags);
238 return gnttab_alloc_pages(1, page);
239 }
240 page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
241 list_del(&page[0]->lru);
242 free_pages_num--;
243 spin_unlock_irqrestore(&free_pages_lock, flags);
244 return 0;
245 }
246
247 static unsigned long vaddr_page(struct page *page)
248 {
249 unsigned long pfn = page_to_pfn(page);
250
251 return (unsigned long)pfn_to_kaddr(pfn);
252 }
253
254 static unsigned long vaddr(struct vscsibk_pend *req, int seg)
255 {
256 return vaddr_page(req->pages[seg]);
257 }
258
259 static void scsiback_print_status(char *sense_buffer, int errors,
260 struct vscsibk_pend *pending_req)
261 {
262 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
263
264 pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n",
265 tpg->tport->tport_name, pending_req->v2p->lun,
266 pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
267 host_byte(errors), driver_byte(errors));
268 }
269
270 static void scsiback_fast_flush_area(struct vscsibk_pend *req)
271 {
272 struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
273 struct page *pages[VSCSI_GRANT_BATCH];
274 unsigned int i, invcount = 0;
275 grant_handle_t handle;
276 int err;
277
278 kfree(req->sgl);
279 req->sgl = NULL;
280 req->n_sg = 0;
281
282 if (!req->n_grants)
283 return;
284
285 for (i = 0; i < req->n_grants; i++) {
286 handle = req->grant_handles[i];
287 if (handle == SCSIBACK_INVALID_HANDLE)
288 continue;
289 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
290 GNTMAP_host_map, handle);
291 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
292 pages[invcount] = req->pages[i];
293 put_page(pages[invcount]);
294 invcount++;
295 if (invcount < VSCSI_GRANT_BATCH)
296 continue;
297 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
298 BUG_ON(err);
299 invcount = 0;
300 }
301
302 if (invcount) {
303 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
304 BUG_ON(err);
305 }
306
307 put_free_pages(req->pages, req->n_grants);
308 req->n_grants = 0;
309 }
310
311 static void scsiback_free_translation_entry(struct kref *kref)
312 {
313 struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
314 struct scsiback_tpg *tpg = entry->tpg;
315
316 mutex_lock(&tpg->tv_tpg_mutex);
317 tpg->tv_tpg_fe_count--;
318 mutex_unlock(&tpg->tv_tpg_mutex);
319
320 kfree(entry);
321 }
322
323 static void scsiback_send_response(struct vscsibk_info *info,
324 char *sense_buffer, int32_t result, uint32_t resid,
325 uint16_t rqid)
326 {
327 struct vscsiif_response *ring_res;
328 int notify;
329 struct scsi_sense_hdr sshdr;
330 unsigned long flags;
331 unsigned len;
332
333 spin_lock_irqsave(&info->ring_lock, flags);
334
335 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
336 info->ring.rsp_prod_pvt++;
337
338 ring_res->rslt = result;
339 ring_res->rqid = rqid;
340
341 if (sense_buffer != NULL &&
342 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
343 &sshdr)) {
344 len = min_t(unsigned, 8 + sense_buffer[7],
345 VSCSIIF_SENSE_BUFFERSIZE);
346 memcpy(ring_res->sense_buffer, sense_buffer, len);
347 ring_res->sense_len = len;
348 } else {
349 ring_res->sense_len = 0;
350 }
351
352 ring_res->residual_len = resid;
353
354 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
355 spin_unlock_irqrestore(&info->ring_lock, flags);
356
357 if (notify)
358 notify_remote_via_irq(info->irq);
359 }
360
361 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
362 uint32_t resid, struct vscsibk_pend *pending_req)
363 {
364 scsiback_send_response(pending_req->info, sense_buffer, result,
365 resid, pending_req->rqid);
366
367 if (pending_req->v2p)
368 kref_put(&pending_req->v2p->kref,
369 scsiback_free_translation_entry);
370 }
371
372 static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
373 {
374 struct vscsibk_info *info = pending_req->info;
375 unsigned char *sense_buffer;
376 unsigned int resid;
377 int errors;
378
379 sense_buffer = pending_req->sense_buffer;
380 resid = pending_req->se_cmd.residual_count;
381 errors = pending_req->result;
382
383 if (errors && log_print_stat)
384 scsiback_print_status(sense_buffer, errors, pending_req);
385
386 scsiback_fast_flush_area(pending_req);
387 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
388 scsiback_put(info);
389 /*
390 * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls()
391 * ahead of scsiback_check_stop_free() -> transport_generic_free_cmd()
392 * final se_cmd->cmd_kref put.
393 */
394 target_put_sess_cmd(&pending_req->se_cmd);
395 }
396
397 static 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 scsiback_get(pending_req->info);
404 se_cmd->tag = pending_req->rqid;
405 rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
406 pending_req->sense_buffer, pending_req->v2p->lun,
407 pending_req->data_len, 0,
408 pending_req->sc_data_direction, TARGET_SCF_ACK_KREF,
409 pending_req->sgl, pending_req->n_sg,
410 NULL, 0, NULL, 0);
411 if (rc < 0) {
412 transport_send_check_condition_and_sense(se_cmd,
413 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
414 transport_generic_free_cmd(se_cmd, 0);
415 }
416 }
417
418 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
419 struct page **pg, grant_handle_t *grant, int cnt)
420 {
421 int err, i;
422
423 if (!cnt)
424 return 0;
425
426 err = gnttab_map_refs(map, NULL, pg, cnt);
427 BUG_ON(err);
428 for (i = 0; i < cnt; i++) {
429 if (unlikely(map[i].status != GNTST_okay)) {
430 pr_err("invalid buffer -- could not remap it\n");
431 map[i].handle = SCSIBACK_INVALID_HANDLE;
432 err = -ENOMEM;
433 } else {
434 get_page(pg[i]);
435 }
436 grant[i] = map[i].handle;
437 }
438 return err;
439 }
440
441 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
442 struct scsiif_request_segment *seg, struct page **pg,
443 grant_handle_t *grant, int cnt, u32 flags)
444 {
445 int mapcount = 0, i, err = 0;
446 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
447 struct vscsibk_info *info = pending_req->info;
448
449 for (i = 0; i < cnt; i++) {
450 if (get_free_page(pg + mapcount)) {
451 put_free_pages(pg, mapcount);
452 pr_err("no grant page\n");
453 return -ENOMEM;
454 }
455 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
456 flags, seg[i].gref, info->domid);
457 mapcount++;
458 if (mapcount < VSCSI_GRANT_BATCH)
459 continue;
460 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
461 pg += mapcount;
462 grant += mapcount;
463 pending_req->n_grants += mapcount;
464 if (err)
465 return err;
466 mapcount = 0;
467 }
468 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
469 pending_req->n_grants += mapcount;
470 return err;
471 }
472
473 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
474 struct vscsibk_pend *pending_req)
475 {
476 u32 flags;
477 int i, err, n_segs, i_seg = 0;
478 struct page **pg;
479 struct scsiif_request_segment *seg;
480 unsigned long end_seg = 0;
481 unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
482 unsigned int nr_sgl = 0;
483 struct scatterlist *sg;
484 grant_handle_t *grant;
485
486 pending_req->n_sg = 0;
487 pending_req->n_grants = 0;
488 pending_req->data_len = 0;
489
490 nr_segments &= ~VSCSIIF_SG_GRANT;
491 if (!nr_segments)
492 return 0;
493
494 if (nr_segments > VSCSIIF_SG_TABLESIZE) {
495 pr_debug("invalid parameter nr_seg = %d\n",
496 ring_req->nr_segments);
497 return -EINVAL;
498 }
499
500 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
501 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
502 pending_req->pages, pending_req->grant_handles,
503 nr_segments, GNTMAP_host_map | GNTMAP_readonly);
504 if (err)
505 return err;
506 nr_sgl = nr_segments;
507 nr_segments = 0;
508 for (i = 0; i < nr_sgl; i++) {
509 n_segs = ring_req->seg[i].length /
510 sizeof(struct scsiif_request_segment);
511 if ((unsigned)ring_req->seg[i].offset +
512 (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
513 n_segs * sizeof(struct scsiif_request_segment) !=
514 ring_req->seg[i].length)
515 return -EINVAL;
516 nr_segments += n_segs;
517 }
518 if (nr_segments > SG_ALL) {
519 pr_debug("invalid nr_seg = %d\n", nr_segments);
520 return -EINVAL;
521 }
522 }
523
524 /* free of (sgl) in fast_flush_area() */
525 pending_req->sgl = kmalloc_array(nr_segments,
526 sizeof(struct scatterlist), GFP_KERNEL);
527 if (!pending_req->sgl)
528 return -ENOMEM;
529
530 sg_init_table(pending_req->sgl, nr_segments);
531 pending_req->n_sg = nr_segments;
532
533 flags = GNTMAP_host_map;
534 if (pending_req->sc_data_direction == DMA_TO_DEVICE)
535 flags |= GNTMAP_readonly;
536
537 pg = pending_req->pages + nr_sgl;
538 grant = pending_req->grant_handles + nr_sgl;
539 if (!nr_sgl) {
540 seg = ring_req->seg;
541 err = scsiback_gnttab_data_map_list(pending_req, seg,
542 pg, grant, nr_segments, flags);
543 if (err)
544 return err;
545 } else {
546 for (i = 0; i < nr_sgl; i++) {
547 seg = (struct scsiif_request_segment *)(
548 vaddr(pending_req, i) + ring_req->seg[i].offset);
549 n_segs = ring_req->seg[i].length /
550 sizeof(struct scsiif_request_segment);
551 err = scsiback_gnttab_data_map_list(pending_req, seg,
552 pg, grant, n_segs, flags);
553 if (err)
554 return err;
555 pg += n_segs;
556 grant += n_segs;
557 }
558 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
559 seg = (struct scsiif_request_segment *)end_seg;
560 end_seg += ring_req->seg[0].length;
561 pg = pending_req->pages + nr_sgl;
562 }
563
564 for_each_sg(pending_req->sgl, sg, nr_segments, i) {
565 sg_set_page(sg, pg[i], seg->length, seg->offset);
566 pending_req->data_len += seg->length;
567 seg++;
568 if (nr_sgl && (unsigned long)seg >= end_seg) {
569 i_seg++;
570 end_seg = vaddr(pending_req, i_seg) +
571 ring_req->seg[i_seg].offset;
572 seg = (struct scsiif_request_segment *)end_seg;
573 end_seg += ring_req->seg[i_seg].length;
574 }
575 if (sg->offset >= PAGE_SIZE ||
576 sg->length > PAGE_SIZE ||
577 sg->offset + sg->length > PAGE_SIZE)
578 return -EINVAL;
579 }
580
581 return 0;
582 }
583
584 static void scsiback_disconnect(struct vscsibk_info *info)
585 {
586 wait_event(info->waiting_to_free,
587 atomic_read(&info->nr_unreplied_reqs) == 0);
588
589 unbind_from_irqhandler(info->irq, info);
590 info->irq = 0;
591 xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
592 }
593
594 static void scsiback_device_action(struct vscsibk_pend *pending_req,
595 enum tcm_tmreq_table act, int tag)
596 {
597 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
598 struct scsiback_nexus *nexus = tpg->tpg_nexus;
599 struct se_cmd *se_cmd = &pending_req->se_cmd;
600 u64 unpacked_lun = pending_req->v2p->lun;
601 int rc, err = FAILED;
602
603 init_waitqueue_head(&pending_req->tmr_wait);
604
605 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess,
606 &pending_req->sense_buffer[0],
607 unpacked_lun, NULL, act, GFP_KERNEL,
608 tag, TARGET_SCF_ACK_KREF);
609 if (rc)
610 goto err;
611
612 wait_event(pending_req->tmr_wait,
613 atomic_read(&pending_req->tmr_complete));
614
615 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
616 SUCCESS : FAILED;
617
618 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
619 transport_generic_free_cmd(&pending_req->se_cmd, 1);
620 return;
621
622 err:
623 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
624 }
625
626 /*
627 Perform virtual to physical translation
628 */
629 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
630 struct ids_tuple *v)
631 {
632 struct v2p_entry *entry;
633 struct list_head *head = &(info->v2p_entry_lists);
634 unsigned long flags;
635
636 spin_lock_irqsave(&info->v2p_lock, flags);
637 list_for_each_entry(entry, head, l) {
638 if ((entry->v.chn == v->chn) &&
639 (entry->v.tgt == v->tgt) &&
640 (entry->v.lun == v->lun)) {
641 kref_get(&entry->kref);
642 goto out;
643 }
644 }
645 entry = NULL;
646
647 out:
648 spin_unlock_irqrestore(&info->v2p_lock, flags);
649 return entry;
650 }
651
652 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring,
653 struct v2p_entry *v2p)
654 {
655 struct scsiback_tpg *tpg = v2p->tpg;
656 struct scsiback_nexus *nexus = tpg->tpg_nexus;
657 struct se_session *se_sess = nexus->tvn_se_sess;
658 struct vscsibk_pend *req;
659 int tag, i;
660
661 tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
662 if (tag < 0) {
663 pr_err("Unable to obtain tag for vscsiif_request\n");
664 return ERR_PTR(-ENOMEM);
665 }
666
667 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
668 memset(req, 0, sizeof(*req));
669 req->se_cmd.map_tag = tag;
670
671 for (i = 0; i < VSCSI_MAX_GRANTS; i++)
672 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
673
674 return req;
675 }
676
677 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
678 struct vscsiif_back_ring *ring,
679 struct vscsiif_request *ring_req)
680 {
681 struct vscsibk_pend *pending_req;
682 struct v2p_entry *v2p;
683 struct ids_tuple vir;
684
685 /* request range check from frontend */
686 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
687 (ring_req->sc_data_direction != DMA_TO_DEVICE) &&
688 (ring_req->sc_data_direction != DMA_FROM_DEVICE) &&
689 (ring_req->sc_data_direction != DMA_NONE)) {
690 pr_debug("invalid parameter data_dir = %d\n",
691 ring_req->sc_data_direction);
692 return ERR_PTR(-EINVAL);
693 }
694 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
695 pr_debug("invalid parameter cmd_len = %d\n",
696 ring_req->cmd_len);
697 return ERR_PTR(-EINVAL);
698 }
699
700 vir.chn = ring_req->channel;
701 vir.tgt = ring_req->id;
702 vir.lun = ring_req->lun;
703
704 v2p = scsiback_do_translation(info, &vir);
705 if (!v2p) {
706 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
707 vir.chn, vir.tgt, vir.lun);
708 return ERR_PTR(-ENODEV);
709 }
710
711 pending_req = scsiback_get_pend_req(ring, v2p);
712 if (IS_ERR(pending_req)) {
713 kref_put(&v2p->kref, scsiback_free_translation_entry);
714 return ERR_PTR(-ENOMEM);
715 }
716 pending_req->rqid = ring_req->rqid;
717 pending_req->info = info;
718 pending_req->v2p = v2p;
719 pending_req->sc_data_direction = ring_req->sc_data_direction;
720 pending_req->cmd_len = ring_req->cmd_len;
721 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
722
723 return pending_req;
724 }
725
726 static int scsiback_do_cmd_fn(struct vscsibk_info *info)
727 {
728 struct vscsiif_back_ring *ring = &info->ring;
729 struct vscsiif_request ring_req;
730 struct vscsibk_pend *pending_req;
731 RING_IDX rc, rp;
732 int more_to_do;
733 uint32_t result;
734
735 rc = ring->req_cons;
736 rp = ring->sring->req_prod;
737 rmb(); /* guest system is accessing ring, too */
738
739 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
740 rc = ring->rsp_prod_pvt;
741 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
742 info->domid, rp, rc, rp - rc);
743 info->ring_error = 1;
744 return 0;
745 }
746
747 while ((rc != rp)) {
748 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
749 break;
750
751 RING_COPY_REQUEST(ring, rc, &ring_req);
752 ring->req_cons = ++rc;
753
754 pending_req = prepare_pending_reqs(info, ring, &ring_req);
755 if (IS_ERR(pending_req)) {
756 switch (PTR_ERR(pending_req)) {
757 case -ENODEV:
758 result = DID_NO_CONNECT;
759 break;
760 default:
761 result = DRIVER_ERROR;
762 break;
763 }
764 scsiback_send_response(info, NULL, result << 24, 0,
765 ring_req.rqid);
766 return 1;
767 }
768
769 switch (ring_req.act) {
770 case VSCSIIF_ACT_SCSI_CDB:
771 if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
772 scsiback_fast_flush_area(pending_req);
773 scsiback_do_resp_with_sense(NULL,
774 DRIVER_ERROR << 24, 0, pending_req);
775 transport_generic_free_cmd(&pending_req->se_cmd, 0);
776 } else {
777 scsiback_cmd_exec(pending_req);
778 }
779 break;
780 case VSCSIIF_ACT_SCSI_ABORT:
781 scsiback_device_action(pending_req, TMR_ABORT_TASK,
782 ring_req.ref_rqid);
783 break;
784 case VSCSIIF_ACT_SCSI_RESET:
785 scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
786 break;
787 default:
788 pr_err_ratelimited("invalid request\n");
789 scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24, 0,
790 pending_req);
791 transport_generic_free_cmd(&pending_req->se_cmd, 0);
792 break;
793 }
794
795 /* Yield point for this unbounded loop. */
796 cond_resched();
797 }
798
799 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
800 return more_to_do;
801 }
802
803 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
804 {
805 struct vscsibk_info *info = dev_id;
806
807 if (info->ring_error)
808 return IRQ_HANDLED;
809
810 while (scsiback_do_cmd_fn(info))
811 cond_resched();
812
813 return IRQ_HANDLED;
814 }
815
816 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
817 evtchn_port_t evtchn)
818 {
819 void *area;
820 struct vscsiif_sring *sring;
821 int err;
822
823 if (info->irq)
824 return -1;
825
826 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
827 if (err)
828 return err;
829
830 sring = (struct vscsiif_sring *)area;
831 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
832
833 err = bind_interdomain_evtchn_to_irq(info->domid, evtchn);
834 if (err < 0)
835 goto unmap_page;
836
837 info->irq = err;
838
839 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
840 IRQF_ONESHOT, "vscsiif-backend", info);
841 if (err)
842 goto free_irq;
843
844 return 0;
845
846 free_irq:
847 unbind_from_irqhandler(info->irq, info);
848 info->irq = 0;
849 unmap_page:
850 xenbus_unmap_ring_vfree(info->dev, area);
851
852 return err;
853 }
854
855 static int scsiback_map(struct vscsibk_info *info)
856 {
857 struct xenbus_device *dev = info->dev;
858 unsigned int ring_ref, evtchn;
859 int err;
860
861 err = xenbus_gather(XBT_NIL, dev->otherend,
862 "ring-ref", "%u", &ring_ref,
863 "event-channel", "%u", &evtchn, NULL);
864 if (err) {
865 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
866 return err;
867 }
868
869 return scsiback_init_sring(info, ring_ref, evtchn);
870 }
871
872 /*
873 Check for a translation entry being present
874 */
875 static struct v2p_entry *scsiback_chk_translation_entry(
876 struct vscsibk_info *info, struct ids_tuple *v)
877 {
878 struct list_head *head = &(info->v2p_entry_lists);
879 struct v2p_entry *entry;
880
881 list_for_each_entry(entry, head, l)
882 if ((entry->v.chn == v->chn) &&
883 (entry->v.tgt == v->tgt) &&
884 (entry->v.lun == v->lun))
885 return entry;
886
887 return NULL;
888 }
889
890 /*
891 Add a new translation entry
892 */
893 static int scsiback_add_translation_entry(struct vscsibk_info *info,
894 char *phy, struct ids_tuple *v)
895 {
896 int err = 0;
897 struct v2p_entry *new;
898 unsigned long flags;
899 char *lunp;
900 unsigned long long unpacked_lun;
901 struct se_lun *se_lun;
902 struct scsiback_tpg *tpg_entry, *tpg = NULL;
903 char *error = "doesn't exist";
904
905 lunp = strrchr(phy, ':');
906 if (!lunp) {
907 pr_err("illegal format of physical device %s\n", phy);
908 return -EINVAL;
909 }
910 *lunp = 0;
911 lunp++;
912 err = kstrtoull(lunp, 10, &unpacked_lun);
913 if (err < 0) {
914 pr_err("lun number not valid: %s\n", lunp);
915 return err;
916 }
917
918 mutex_lock(&scsiback_mutex);
919 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
920 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
921 !strcmp(phy, tpg_entry->param_alias)) {
922 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex);
923 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) {
924 if (se_lun->unpacked_lun == unpacked_lun) {
925 if (!tpg_entry->tpg_nexus)
926 error = "nexus undefined";
927 else
928 tpg = tpg_entry;
929 break;
930 }
931 }
932 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex);
933 break;
934 }
935 }
936 if (tpg) {
937 mutex_lock(&tpg->tv_tpg_mutex);
938 tpg->tv_tpg_fe_count++;
939 mutex_unlock(&tpg->tv_tpg_mutex);
940 }
941 mutex_unlock(&scsiback_mutex);
942
943 if (!tpg) {
944 pr_err("%s:%llu %s\n", phy, unpacked_lun, error);
945 return -ENODEV;
946 }
947
948 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
949 if (new == NULL) {
950 err = -ENOMEM;
951 goto out_free;
952 }
953
954 spin_lock_irqsave(&info->v2p_lock, flags);
955
956 /* Check double assignment to identical virtual ID */
957 if (scsiback_chk_translation_entry(info, v)) {
958 pr_warn("Virtual ID is already used. Assignment was not performed.\n");
959 err = -EEXIST;
960 goto out;
961 }
962
963 /* Create a new translation entry and add to the list */
964 kref_init(&new->kref);
965 new->v = *v;
966 new->tpg = tpg;
967 new->lun = unpacked_lun;
968 list_add_tail(&new->l, &info->v2p_entry_lists);
969
970 out:
971 spin_unlock_irqrestore(&info->v2p_lock, flags);
972
973 out_free:
974 if (err) {
975 mutex_lock(&tpg->tv_tpg_mutex);
976 tpg->tv_tpg_fe_count--;
977 mutex_unlock(&tpg->tv_tpg_mutex);
978 kfree(new);
979 }
980
981 return err;
982 }
983
984 static void __scsiback_del_translation_entry(struct v2p_entry *entry)
985 {
986 list_del(&entry->l);
987 kref_put(&entry->kref, scsiback_free_translation_entry);
988 }
989
990 /*
991 Delete the translation entry specified
992 */
993 static int scsiback_del_translation_entry(struct vscsibk_info *info,
994 struct ids_tuple *v)
995 {
996 struct v2p_entry *entry;
997 unsigned long flags;
998 int ret = 0;
999
1000 spin_lock_irqsave(&info->v2p_lock, flags);
1001 /* Find out the translation entry specified */
1002 entry = scsiback_chk_translation_entry(info, v);
1003 if (entry)
1004 __scsiback_del_translation_entry(entry);
1005 else
1006 ret = -ENOENT;
1007
1008 spin_unlock_irqrestore(&info->v2p_lock, flags);
1009 return ret;
1010 }
1011
1012 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
1013 char *phy, struct ids_tuple *vir, int try)
1014 {
1015 struct v2p_entry *entry;
1016 unsigned long flags;
1017
1018 if (try) {
1019 spin_lock_irqsave(&info->v2p_lock, flags);
1020 entry = scsiback_chk_translation_entry(info, vir);
1021 spin_unlock_irqrestore(&info->v2p_lock, flags);
1022 if (entry)
1023 return;
1024 }
1025 if (!scsiback_add_translation_entry(info, phy, vir)) {
1026 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1027 "%d", XenbusStateInitialised)) {
1028 pr_err("xenbus_printf error %s\n", state);
1029 scsiback_del_translation_entry(info, vir);
1030 }
1031 } else if (!try) {
1032 xenbus_printf(XBT_NIL, info->dev->nodename, state,
1033 "%d", XenbusStateClosed);
1034 }
1035 }
1036
1037 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1038 struct ids_tuple *vir)
1039 {
1040 if (!scsiback_del_translation_entry(info, vir)) {
1041 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1042 "%d", XenbusStateClosed))
1043 pr_err("xenbus_printf error %s\n", state);
1044 }
1045 }
1046
1047 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1
1048 #define VSCSIBACK_OP_UPDATEDEV_STATE 2
1049
1050 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1051 char *ent)
1052 {
1053 int err;
1054 struct ids_tuple vir;
1055 char *val;
1056 int device_state;
1057 char phy[VSCSI_NAMELEN];
1058 char str[64];
1059 char state[64];
1060 struct xenbus_device *dev = info->dev;
1061
1062 /* read status */
1063 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1064 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1065 if (XENBUS_EXIST_ERR(err))
1066 return;
1067
1068 /* physical SCSI device */
1069 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1070 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1071 if (IS_ERR(val)) {
1072 xenbus_printf(XBT_NIL, dev->nodename, state,
1073 "%d", XenbusStateClosed);
1074 return;
1075 }
1076 strlcpy(phy, val, VSCSI_NAMELEN);
1077 kfree(val);
1078
1079 /* virtual SCSI device */
1080 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1081 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1082 &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1083 if (XENBUS_EXIST_ERR(err)) {
1084 xenbus_printf(XBT_NIL, dev->nodename, state,
1085 "%d", XenbusStateClosed);
1086 return;
1087 }
1088
1089 switch (op) {
1090 case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1091 switch (device_state) {
1092 case XenbusStateInitialising:
1093 scsiback_do_add_lun(info, state, phy, &vir, 0);
1094 break;
1095 case XenbusStateConnected:
1096 scsiback_do_add_lun(info, state, phy, &vir, 1);
1097 break;
1098 case XenbusStateClosing:
1099 scsiback_do_del_lun(info, state, &vir);
1100 break;
1101 default:
1102 break;
1103 }
1104 break;
1105
1106 case VSCSIBACK_OP_UPDATEDEV_STATE:
1107 if (device_state == XenbusStateInitialised) {
1108 /* modify vscsi-devs/dev-x/state */
1109 if (xenbus_printf(XBT_NIL, dev->nodename, state,
1110 "%d", XenbusStateConnected)) {
1111 pr_err("xenbus_printf error %s\n", str);
1112 scsiback_del_translation_entry(info, &vir);
1113 xenbus_printf(XBT_NIL, dev->nodename, state,
1114 "%d", XenbusStateClosed);
1115 }
1116 }
1117 break;
1118 /* When it is necessary, processing is added here. */
1119 default:
1120 break;
1121 }
1122 }
1123
1124 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1125 {
1126 int i;
1127 char **dir;
1128 unsigned int ndir = 0;
1129
1130 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1131 &ndir);
1132 if (IS_ERR(dir))
1133 return;
1134
1135 for (i = 0; i < ndir; i++)
1136 scsiback_do_1lun_hotplug(info, op, dir[i]);
1137
1138 kfree(dir);
1139 }
1140
1141 static void scsiback_frontend_changed(struct xenbus_device *dev,
1142 enum xenbus_state frontend_state)
1143 {
1144 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1145
1146 switch (frontend_state) {
1147 case XenbusStateInitialising:
1148 break;
1149
1150 case XenbusStateInitialised:
1151 if (scsiback_map(info))
1152 break;
1153
1154 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1155 xenbus_switch_state(dev, XenbusStateConnected);
1156 break;
1157
1158 case XenbusStateConnected:
1159 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1160
1161 if (dev->state == XenbusStateConnected)
1162 break;
1163
1164 xenbus_switch_state(dev, XenbusStateConnected);
1165 break;
1166
1167 case XenbusStateClosing:
1168 if (info->irq)
1169 scsiback_disconnect(info);
1170
1171 xenbus_switch_state(dev, XenbusStateClosing);
1172 break;
1173
1174 case XenbusStateClosed:
1175 xenbus_switch_state(dev, XenbusStateClosed);
1176 if (xenbus_dev_is_online(dev))
1177 break;
1178 /* fall through if not online */
1179 case XenbusStateUnknown:
1180 device_unregister(&dev->dev);
1181 break;
1182
1183 case XenbusStateReconfiguring:
1184 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1185 xenbus_switch_state(dev, XenbusStateReconfigured);
1186
1187 break;
1188
1189 default:
1190 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1191 frontend_state);
1192 break;
1193 }
1194 }
1195
1196 /*
1197 Release the translation entry specfied
1198 */
1199 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1200 {
1201 struct v2p_entry *entry, *tmp;
1202 struct list_head *head = &(info->v2p_entry_lists);
1203 unsigned long flags;
1204
1205 spin_lock_irqsave(&info->v2p_lock, flags);
1206
1207 list_for_each_entry_safe(entry, tmp, head, l)
1208 __scsiback_del_translation_entry(entry);
1209
1210 spin_unlock_irqrestore(&info->v2p_lock, flags);
1211 }
1212
1213 static int scsiback_remove(struct xenbus_device *dev)
1214 {
1215 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1216
1217 if (info->irq)
1218 scsiback_disconnect(info);
1219
1220 scsiback_release_translation_entry(info);
1221
1222 dev_set_drvdata(&dev->dev, NULL);
1223
1224 return 0;
1225 }
1226
1227 static int scsiback_probe(struct xenbus_device *dev,
1228 const struct xenbus_device_id *id)
1229 {
1230 int err;
1231
1232 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1233 GFP_KERNEL);
1234
1235 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
1236
1237 if (!info) {
1238 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1239 return -ENOMEM;
1240 }
1241 info->dev = dev;
1242 dev_set_drvdata(&dev->dev, info);
1243
1244 info->domid = dev->otherend_id;
1245 spin_lock_init(&info->ring_lock);
1246 info->ring_error = 0;
1247 atomic_set(&info->nr_unreplied_reqs, 0);
1248 init_waitqueue_head(&info->waiting_to_free);
1249 info->dev = dev;
1250 info->irq = 0;
1251 INIT_LIST_HEAD(&info->v2p_entry_lists);
1252 spin_lock_init(&info->v2p_lock);
1253
1254 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1255 SG_ALL);
1256 if (err)
1257 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1258
1259 err = xenbus_switch_state(dev, XenbusStateInitWait);
1260 if (err)
1261 goto fail;
1262
1263 return 0;
1264
1265 fail:
1266 pr_warn("%s failed\n", __func__);
1267 scsiback_remove(dev);
1268
1269 return err;
1270 }
1271
1272 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1273 {
1274 switch (tport->tport_proto_id) {
1275 case SCSI_PROTOCOL_SAS:
1276 return "SAS";
1277 case SCSI_PROTOCOL_FCP:
1278 return "FCP";
1279 case SCSI_PROTOCOL_ISCSI:
1280 return "iSCSI";
1281 default:
1282 break;
1283 }
1284
1285 return "Unknown";
1286 }
1287
1288 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1289 {
1290 struct scsiback_tpg *tpg = container_of(se_tpg,
1291 struct scsiback_tpg, se_tpg);
1292 struct scsiback_tport *tport = tpg->tport;
1293
1294 return &tport->tport_name[0];
1295 }
1296
1297 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1298 {
1299 struct scsiback_tpg *tpg = container_of(se_tpg,
1300 struct scsiback_tpg, se_tpg);
1301 return tpg->tport_tpgt;
1302 }
1303
1304 static struct se_wwn *
1305 scsiback_make_tport(struct target_fabric_configfs *tf,
1306 struct config_group *group,
1307 const char *name)
1308 {
1309 struct scsiback_tport *tport;
1310 char *ptr;
1311 u64 wwpn = 0;
1312 int off = 0;
1313
1314 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1315 if (!tport)
1316 return ERR_PTR(-ENOMEM);
1317
1318 tport->tport_wwpn = wwpn;
1319 /*
1320 * Determine the emulated Protocol Identifier and Target Port Name
1321 * based on the incoming configfs directory name.
1322 */
1323 ptr = strstr(name, "naa.");
1324 if (ptr) {
1325 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1326 goto check_len;
1327 }
1328 ptr = strstr(name, "fc.");
1329 if (ptr) {
1330 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1331 off = 3; /* Skip over "fc." */
1332 goto check_len;
1333 }
1334 ptr = strstr(name, "iqn.");
1335 if (ptr) {
1336 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1337 goto check_len;
1338 }
1339
1340 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1341 kfree(tport);
1342 return ERR_PTR(-EINVAL);
1343
1344 check_len:
1345 if (strlen(name) >= VSCSI_NAMELEN) {
1346 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1347 scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1348 kfree(tport);
1349 return ERR_PTR(-EINVAL);
1350 }
1351 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1352
1353 pr_debug("Allocated emulated Target %s Address: %s\n",
1354 scsiback_dump_proto_id(tport), name);
1355
1356 return &tport->tport_wwn;
1357 }
1358
1359 static void scsiback_drop_tport(struct se_wwn *wwn)
1360 {
1361 struct scsiback_tport *tport = container_of(wwn,
1362 struct scsiback_tport, tport_wwn);
1363
1364 pr_debug("Deallocating emulated Target %s Address: %s\n",
1365 scsiback_dump_proto_id(tport), tport->tport_name);
1366
1367 kfree(tport);
1368 }
1369
1370 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1371 {
1372 return 1;
1373 }
1374
1375 static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1376 {
1377 return transport_generic_free_cmd(se_cmd, 0);
1378 }
1379
1380 static void scsiback_release_cmd(struct se_cmd *se_cmd)
1381 {
1382 struct se_session *se_sess = se_cmd->se_sess;
1383
1384 percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
1385 }
1386
1387 static u32 scsiback_sess_get_index(struct se_session *se_sess)
1388 {
1389 return 0;
1390 }
1391
1392 static int scsiback_write_pending(struct se_cmd *se_cmd)
1393 {
1394 /* Go ahead and process the write immediately */
1395 target_execute_cmd(se_cmd);
1396
1397 return 0;
1398 }
1399
1400 static int scsiback_write_pending_status(struct se_cmd *se_cmd)
1401 {
1402 return 0;
1403 }
1404
1405 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1406 {
1407 }
1408
1409 static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1410 {
1411 return 0;
1412 }
1413
1414 static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1415 {
1416 struct vscsibk_pend *pending_req = container_of(se_cmd,
1417 struct vscsibk_pend, se_cmd);
1418
1419 pending_req->result = SAM_STAT_GOOD;
1420 scsiback_cmd_done(pending_req);
1421 return 0;
1422 }
1423
1424 static int scsiback_queue_status(struct se_cmd *se_cmd)
1425 {
1426 struct vscsibk_pend *pending_req = container_of(se_cmd,
1427 struct vscsibk_pend, se_cmd);
1428
1429 if (se_cmd->sense_buffer &&
1430 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1431 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1432 pending_req->result = (DRIVER_SENSE << 24) |
1433 SAM_STAT_CHECK_CONDITION;
1434 else
1435 pending_req->result = se_cmd->scsi_status;
1436
1437 scsiback_cmd_done(pending_req);
1438 return 0;
1439 }
1440
1441 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1442 {
1443 struct vscsibk_pend *pending_req = container_of(se_cmd,
1444 struct vscsibk_pend, se_cmd);
1445
1446 atomic_set(&pending_req->tmr_complete, 1);
1447 wake_up(&pending_req->tmr_wait);
1448 }
1449
1450 static void scsiback_aborted_task(struct se_cmd *se_cmd)
1451 {
1452 }
1453
1454 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item,
1455 char *page)
1456 {
1457 struct se_portal_group *se_tpg = param_to_tpg(item);
1458 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1459 se_tpg);
1460 ssize_t rb;
1461
1462 mutex_lock(&tpg->tv_tpg_mutex);
1463 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1464 mutex_unlock(&tpg->tv_tpg_mutex);
1465
1466 return rb;
1467 }
1468
1469 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item,
1470 const char *page, size_t count)
1471 {
1472 struct se_portal_group *se_tpg = param_to_tpg(item);
1473 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1474 se_tpg);
1475 int len;
1476
1477 if (strlen(page) >= VSCSI_NAMELEN) {
1478 pr_err("param alias: %s, exceeds max: %d\n", page,
1479 VSCSI_NAMELEN);
1480 return -EINVAL;
1481 }
1482
1483 mutex_lock(&tpg->tv_tpg_mutex);
1484 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1485 if (tpg->param_alias[len - 1] == '\n')
1486 tpg->param_alias[len - 1] = '\0';
1487 mutex_unlock(&tpg->tv_tpg_mutex);
1488
1489 return count;
1490 }
1491
1492 CONFIGFS_ATTR(scsiback_tpg_param_, alias);
1493
1494 static struct configfs_attribute *scsiback_param_attrs[] = {
1495 &scsiback_tpg_param_attr_alias,
1496 NULL,
1497 };
1498
1499 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg,
1500 struct se_session *se_sess, void *p)
1501 {
1502 struct scsiback_tpg *tpg = container_of(se_tpg,
1503 struct scsiback_tpg, se_tpg);
1504
1505 tpg->tpg_nexus = p;
1506 return 0;
1507 }
1508
1509 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1510 const char *name)
1511 {
1512 struct scsiback_nexus *tv_nexus;
1513 int ret = 0;
1514
1515 mutex_lock(&tpg->tv_tpg_mutex);
1516 if (tpg->tpg_nexus) {
1517 pr_debug("tpg->tpg_nexus already exists\n");
1518 ret = -EEXIST;
1519 goto out_unlock;
1520 }
1521
1522 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1523 if (!tv_nexus) {
1524 ret = -ENOMEM;
1525 goto out_unlock;
1526 }
1527
1528 tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg,
1529 VSCSI_DEFAULT_SESSION_TAGS,
1530 sizeof(struct vscsibk_pend),
1531 TARGET_PROT_NORMAL, name,
1532 tv_nexus, scsiback_alloc_sess_cb);
1533 if (IS_ERR(tv_nexus->tvn_se_sess)) {
1534 kfree(tv_nexus);
1535 ret = -ENOMEM;
1536 goto out_unlock;
1537 }
1538
1539 out_unlock:
1540 mutex_unlock(&tpg->tv_tpg_mutex);
1541 return ret;
1542 }
1543
1544 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1545 {
1546 struct se_session *se_sess;
1547 struct scsiback_nexus *tv_nexus;
1548
1549 mutex_lock(&tpg->tv_tpg_mutex);
1550 tv_nexus = tpg->tpg_nexus;
1551 if (!tv_nexus) {
1552 mutex_unlock(&tpg->tv_tpg_mutex);
1553 return -ENODEV;
1554 }
1555
1556 se_sess = tv_nexus->tvn_se_sess;
1557 if (!se_sess) {
1558 mutex_unlock(&tpg->tv_tpg_mutex);
1559 return -ENODEV;
1560 }
1561
1562 if (tpg->tv_tpg_port_count != 0) {
1563 mutex_unlock(&tpg->tv_tpg_mutex);
1564 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1565 tpg->tv_tpg_port_count);
1566 return -EBUSY;
1567 }
1568
1569 if (tpg->tv_tpg_fe_count != 0) {
1570 mutex_unlock(&tpg->tv_tpg_mutex);
1571 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1572 tpg->tv_tpg_fe_count);
1573 return -EBUSY;
1574 }
1575
1576 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1577 scsiback_dump_proto_id(tpg->tport),
1578 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1579
1580 /*
1581 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1582 */
1583 transport_deregister_session(tv_nexus->tvn_se_sess);
1584 tpg->tpg_nexus = NULL;
1585 mutex_unlock(&tpg->tv_tpg_mutex);
1586
1587 kfree(tv_nexus);
1588 return 0;
1589 }
1590
1591 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page)
1592 {
1593 struct se_portal_group *se_tpg = to_tpg(item);
1594 struct scsiback_tpg *tpg = container_of(se_tpg,
1595 struct scsiback_tpg, se_tpg);
1596 struct scsiback_nexus *tv_nexus;
1597 ssize_t ret;
1598
1599 mutex_lock(&tpg->tv_tpg_mutex);
1600 tv_nexus = tpg->tpg_nexus;
1601 if (!tv_nexus) {
1602 mutex_unlock(&tpg->tv_tpg_mutex);
1603 return -ENODEV;
1604 }
1605 ret = snprintf(page, PAGE_SIZE, "%s\n",
1606 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1607 mutex_unlock(&tpg->tv_tpg_mutex);
1608
1609 return ret;
1610 }
1611
1612 static ssize_t scsiback_tpg_nexus_store(struct config_item *item,
1613 const char *page, size_t count)
1614 {
1615 struct se_portal_group *se_tpg = to_tpg(item);
1616 struct scsiback_tpg *tpg = container_of(se_tpg,
1617 struct scsiback_tpg, se_tpg);
1618 struct scsiback_tport *tport_wwn = tpg->tport;
1619 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1620 int ret;
1621 /*
1622 * Shutdown the active I_T nexus if 'NULL' is passed.
1623 */
1624 if (!strncmp(page, "NULL", 4)) {
1625 ret = scsiback_drop_nexus(tpg);
1626 return (!ret) ? count : ret;
1627 }
1628 /*
1629 * Otherwise make sure the passed virtual Initiator port WWN matches
1630 * the fabric protocol_id set in scsiback_make_tport(), and call
1631 * scsiback_make_nexus().
1632 */
1633 if (strlen(page) >= VSCSI_NAMELEN) {
1634 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1635 page, VSCSI_NAMELEN);
1636 return -EINVAL;
1637 }
1638 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1639
1640 ptr = strstr(i_port, "naa.");
1641 if (ptr) {
1642 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1643 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1644 i_port, scsiback_dump_proto_id(tport_wwn));
1645 return -EINVAL;
1646 }
1647 port_ptr = &i_port[0];
1648 goto check_newline;
1649 }
1650 ptr = strstr(i_port, "fc.");
1651 if (ptr) {
1652 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1653 pr_err("Passed FCP 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[3]; /* Skip over "fc." */
1658 goto check_newline;
1659 }
1660 ptr = strstr(i_port, "iqn.");
1661 if (ptr) {
1662 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1663 pr_err("Passed iSCSI 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[0];
1668 goto check_newline;
1669 }
1670 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1671 i_port);
1672 return -EINVAL;
1673 /*
1674 * Clear any trailing newline for the NAA WWN
1675 */
1676 check_newline:
1677 if (i_port[strlen(i_port) - 1] == '\n')
1678 i_port[strlen(i_port) - 1] = '\0';
1679
1680 ret = scsiback_make_nexus(tpg, port_ptr);
1681 if (ret < 0)
1682 return ret;
1683
1684 return count;
1685 }
1686
1687 CONFIGFS_ATTR(scsiback_tpg_, nexus);
1688
1689 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1690 &scsiback_tpg_attr_nexus,
1691 NULL,
1692 };
1693
1694 static ssize_t
1695 scsiback_wwn_version_show(struct config_item *item, char *page)
1696 {
1697 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1698 UTS_RELEASE"\n",
1699 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1700 }
1701
1702 CONFIGFS_ATTR_RO(scsiback_wwn_, version);
1703
1704 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1705 &scsiback_wwn_attr_version,
1706 NULL,
1707 };
1708
1709 static char *scsiback_get_fabric_name(void)
1710 {
1711 return "xen-pvscsi";
1712 }
1713
1714 static int scsiback_port_link(struct se_portal_group *se_tpg,
1715 struct se_lun *lun)
1716 {
1717 struct scsiback_tpg *tpg = container_of(se_tpg,
1718 struct scsiback_tpg, se_tpg);
1719
1720 mutex_lock(&tpg->tv_tpg_mutex);
1721 tpg->tv_tpg_port_count++;
1722 mutex_unlock(&tpg->tv_tpg_mutex);
1723
1724 return 0;
1725 }
1726
1727 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1728 struct se_lun *lun)
1729 {
1730 struct scsiback_tpg *tpg = container_of(se_tpg,
1731 struct scsiback_tpg, se_tpg);
1732
1733 mutex_lock(&tpg->tv_tpg_mutex);
1734 tpg->tv_tpg_port_count--;
1735 mutex_unlock(&tpg->tv_tpg_mutex);
1736 }
1737
1738 static struct se_portal_group *
1739 scsiback_make_tpg(struct se_wwn *wwn,
1740 struct config_group *group,
1741 const char *name)
1742 {
1743 struct scsiback_tport *tport = container_of(wwn,
1744 struct scsiback_tport, tport_wwn);
1745
1746 struct scsiback_tpg *tpg;
1747 u16 tpgt;
1748 int ret;
1749
1750 if (strstr(name, "tpgt_") != name)
1751 return ERR_PTR(-EINVAL);
1752 ret = kstrtou16(name + 5, 10, &tpgt);
1753 if (ret)
1754 return ERR_PTR(ret);
1755
1756 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1757 if (!tpg)
1758 return ERR_PTR(-ENOMEM);
1759
1760 mutex_init(&tpg->tv_tpg_mutex);
1761 INIT_LIST_HEAD(&tpg->tv_tpg_list);
1762 INIT_LIST_HEAD(&tpg->info_list);
1763 tpg->tport = tport;
1764 tpg->tport_tpgt = tpgt;
1765
1766 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
1767 if (ret < 0) {
1768 kfree(tpg);
1769 return NULL;
1770 }
1771 mutex_lock(&scsiback_mutex);
1772 list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1773 mutex_unlock(&scsiback_mutex);
1774
1775 return &tpg->se_tpg;
1776 }
1777
1778 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1779 {
1780 struct scsiback_tpg *tpg = container_of(se_tpg,
1781 struct scsiback_tpg, se_tpg);
1782
1783 mutex_lock(&scsiback_mutex);
1784 list_del(&tpg->tv_tpg_list);
1785 mutex_unlock(&scsiback_mutex);
1786 /*
1787 * Release the virtual I_T Nexus for this xen-pvscsi TPG
1788 */
1789 scsiback_drop_nexus(tpg);
1790 /*
1791 * Deregister the se_tpg from TCM.
1792 */
1793 core_tpg_deregister(se_tpg);
1794 kfree(tpg);
1795 }
1796
1797 static int scsiback_check_true(struct se_portal_group *se_tpg)
1798 {
1799 return 1;
1800 }
1801
1802 static int scsiback_check_false(struct se_portal_group *se_tpg)
1803 {
1804 return 0;
1805 }
1806
1807 static const struct target_core_fabric_ops scsiback_ops = {
1808 .module = THIS_MODULE,
1809 .name = "xen-pvscsi",
1810 .get_fabric_name = scsiback_get_fabric_name,
1811 .tpg_get_wwn = scsiback_get_fabric_wwn,
1812 .tpg_get_tag = scsiback_get_tag,
1813 .tpg_check_demo_mode = scsiback_check_true,
1814 .tpg_check_demo_mode_cache = scsiback_check_true,
1815 .tpg_check_demo_mode_write_protect = scsiback_check_false,
1816 .tpg_check_prod_mode_write_protect = scsiback_check_false,
1817 .tpg_get_inst_index = scsiback_tpg_get_inst_index,
1818 .check_stop_free = scsiback_check_stop_free,
1819 .release_cmd = scsiback_release_cmd,
1820 .sess_get_index = scsiback_sess_get_index,
1821 .sess_get_initiator_sid = NULL,
1822 .write_pending = scsiback_write_pending,
1823 .write_pending_status = scsiback_write_pending_status,
1824 .set_default_node_attributes = scsiback_set_default_node_attrs,
1825 .get_cmd_state = scsiback_get_cmd_state,
1826 .queue_data_in = scsiback_queue_data_in,
1827 .queue_status = scsiback_queue_status,
1828 .queue_tm_rsp = scsiback_queue_tm_rsp,
1829 .aborted_task = scsiback_aborted_task,
1830 /*
1831 * Setup callers for generic logic in target_core_fabric_configfs.c
1832 */
1833 .fabric_make_wwn = scsiback_make_tport,
1834 .fabric_drop_wwn = scsiback_drop_tport,
1835 .fabric_make_tpg = scsiback_make_tpg,
1836 .fabric_drop_tpg = scsiback_drop_tpg,
1837 .fabric_post_link = scsiback_port_link,
1838 .fabric_pre_unlink = scsiback_port_unlink,
1839
1840 .tfc_wwn_attrs = scsiback_wwn_attrs,
1841 .tfc_tpg_base_attrs = scsiback_tpg_attrs,
1842 .tfc_tpg_param_attrs = scsiback_param_attrs,
1843 };
1844
1845 static const struct xenbus_device_id scsiback_ids[] = {
1846 { "vscsi" },
1847 { "" }
1848 };
1849
1850 static struct xenbus_driver scsiback_driver = {
1851 .ids = scsiback_ids,
1852 .probe = scsiback_probe,
1853 .remove = scsiback_remove,
1854 .otherend_changed = scsiback_frontend_changed
1855 };
1856
1857 static int __init scsiback_init(void)
1858 {
1859 int ret;
1860
1861 if (!xen_domain())
1862 return -ENODEV;
1863
1864 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
1865 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1866
1867 ret = xenbus_register_backend(&scsiback_driver);
1868 if (ret)
1869 goto out;
1870
1871 ret = target_register_template(&scsiback_ops);
1872 if (ret)
1873 goto out_unregister_xenbus;
1874
1875 return 0;
1876
1877 out_unregister_xenbus:
1878 xenbus_unregister_driver(&scsiback_driver);
1879 out:
1880 pr_err("%s: error %d\n", __func__, ret);
1881 return ret;
1882 }
1883
1884 static void __exit scsiback_exit(void)
1885 {
1886 struct page *page;
1887
1888 while (free_pages_num) {
1889 if (get_free_page(&page))
1890 BUG();
1891 gnttab_free_pages(1, &page);
1892 }
1893 target_unregister_template(&scsiback_ops);
1894 xenbus_unregister_driver(&scsiback_driver);
1895 }
1896
1897 module_init(scsiback_init);
1898 module_exit(scsiback_exit);
1899
1900 MODULE_DESCRIPTION("Xen SCSI backend driver");
1901 MODULE_LICENSE("Dual BSD/GPL");
1902 MODULE_ALIAS("xen-backend:vscsi");
1903 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
Linux with added FPC-III support