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Merge tag 'trace-printf-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace...
[drm/drm-misc.git] / drivers / xen / xen-scsiback.c
blob0c51edfd13dcdfbb12c988c63c78cd85ea0b086d
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 <linux/module.h>
37 #include <linux/utsname.h>
38 #include <linux/interrupt.h>
39 #include <linux/slab.h>
40 #include <linux/wait.h>
41 #include <linux/sched.h>
42 #include <linux/list.h>
43 #include <linux/gfp.h>
44 #include <linux/delay.h>
45 #include <linux/spinlock.h>
46 #include <linux/configfs.h>
47
48 #include <generated/utsrelease.h>
49
50 #include <scsi/scsi_host.h> /* SG_ALL */
51
52 #include <target/target_core_base.h>
53 #include <target/target_core_fabric.h>
54
55 #include <asm/hypervisor.h>
56
57 #include <xen/xen.h>
58 #include <xen/balloon.h>
59 #include <xen/events.h>
60 #include <xen/xenbus.h>
61 #include <xen/grant_table.h>
62 #include <xen/page.h>
63
64 #include <xen/interface/grant_table.h>
65 #include <xen/interface/io/vscsiif.h>
66
67 #define VSCSI_VERSION "v0.1"
68 #define VSCSI_NAMELEN 32
69
70 struct ids_tuple {
71 unsigned int hst; /* host */
72 unsigned int chn; /* channel */
73 unsigned int tgt; /* target */
74 unsigned int lun; /* LUN */
75 };
76
77 struct v2p_entry {
78 struct ids_tuple v; /* translate from */
79 struct scsiback_tpg *tpg; /* translate to */
80 unsigned int lun;
81 struct kref kref;
82 struct list_head l;
83 };
84
85 struct vscsibk_info {
86 struct xenbus_device *dev;
87
88 domid_t domid;
89 unsigned int irq;
90
91 struct vscsiif_back_ring ring;
92
93 spinlock_t ring_lock;
94 atomic_t nr_unreplied_reqs;
95
96 spinlock_t v2p_lock;
97 struct list_head v2p_entry_lists;
98
99 wait_queue_head_t waiting_to_free;
100
101 struct gnttab_page_cache free_pages;
102 };
103
104 /* theoretical maximum of grants for one request */
105 #define VSCSI_MAX_GRANTS (SG_ALL + VSCSIIF_SG_TABLESIZE)
106
107 /*
108 * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
109 * call to map/unmap grants. Don't choose it too large, as there are arrays
110 * with VSCSI_GRANT_BATCH elements allocated on the stack.
111 */
112 #define VSCSI_GRANT_BATCH 16
113
114 struct vscsibk_pend {
115 uint16_t rqid;
116
117 uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
118 uint8_t cmd_len;
119
120 uint8_t sc_data_direction;
121 uint16_t n_sg; /* real length of SG list */
122 uint16_t n_grants; /* SG pages and potentially SG list */
123 uint32_t data_len;
124 uint32_t result;
125
126 struct vscsibk_info *info;
127 struct v2p_entry *v2p;
128 struct scatterlist *sgl;
129
130 uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
131
132 grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
133 struct page *pages[VSCSI_MAX_GRANTS];
134
135 struct se_cmd se_cmd;
136
137 struct completion tmr_done;
138 };
139
140 #define VSCSI_DEFAULT_SESSION_TAGS 128
141
142 struct scsiback_nexus {
143 /* Pointer to TCM session for I_T Nexus */
144 struct se_session *tvn_se_sess;
145 };
146
147 struct scsiback_tport {
148 /* SCSI protocol the tport is providing */
149 u8 tport_proto_id;
150 /* Binary World Wide unique Port Name for pvscsi Target port */
151 u64 tport_wwpn;
152 /* ASCII formatted WWPN for pvscsi Target port */
153 char tport_name[VSCSI_NAMELEN];
154 /* Returned by scsiback_make_tport() */
155 struct se_wwn tport_wwn;
156 };
157
158 struct scsiback_tpg {
159 /* scsiback port target portal group tag for TCM */
160 u16 tport_tpgt;
161 /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
162 int tv_tpg_port_count;
163 /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
164 int tv_tpg_fe_count;
165 /* list for scsiback_list */
166 struct list_head tv_tpg_list;
167 /* Used to protect access for tpg_nexus */
168 struct mutex tv_tpg_mutex;
169 /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
170 struct scsiback_nexus *tpg_nexus;
171 /* Pointer back to scsiback_tport */
172 struct scsiback_tport *tport;
173 /* Returned by scsiback_make_tpg() */
174 struct se_portal_group se_tpg;
175 /* alias used in xenstore */
176 char param_alias[VSCSI_NAMELEN];
177 /* list of info structures related to this target portal group */
178 struct list_head info_list;
179 };
180
181 #define SCSIBACK_INVALID_HANDLE (~0)
182
183 static bool log_print_stat;
184 module_param(log_print_stat, bool, 0644);
185
186 static int scsiback_max_buffer_pages = 1024;
187 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
188 MODULE_PARM_DESC(max_buffer_pages,
189 "Maximum number of free pages to keep in backend buffer");
190
191 /* Global spinlock to protect scsiback TPG list */
192 static DEFINE_MUTEX(scsiback_mutex);
193 static LIST_HEAD(scsiback_list);
194
195 static void scsiback_get(struct vscsibk_info *info)
196 {
197 atomic_inc(&info->nr_unreplied_reqs);
198 }
199
200 static void scsiback_put(struct vscsibk_info *info)
201 {
202 if (atomic_dec_and_test(&info->nr_unreplied_reqs))
203 wake_up(&info->waiting_to_free);
204 }
205
206 static unsigned long vaddr_page(struct page *page)
207 {
208 unsigned long pfn = page_to_pfn(page);
209
210 return (unsigned long)pfn_to_kaddr(pfn);
211 }
212
213 static unsigned long vaddr(struct vscsibk_pend *req, int seg)
214 {
215 return vaddr_page(req->pages[seg]);
216 }
217
218 static void scsiback_print_status(char *sense_buffer, int errors,
219 struct vscsibk_pend *pending_req)
220 {
221 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
222
223 pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x\n",
224 tpg->tport->tport_name, pending_req->v2p->lun,
225 pending_req->cmnd[0], errors & 0xff, COMMAND_COMPLETE,
226 host_byte(errors));
227 }
228
229 static void scsiback_fast_flush_area(struct vscsibk_pend *req)
230 {
231 struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
232 struct page *pages[VSCSI_GRANT_BATCH];
233 unsigned int i, invcount = 0;
234 grant_handle_t handle;
235 int err;
236
237 kfree(req->sgl);
238 req->sgl = NULL;
239 req->n_sg = 0;
240
241 if (!req->n_grants)
242 return;
243
244 for (i = 0; i < req->n_grants; i++) {
245 handle = req->grant_handles[i];
246 if (handle == SCSIBACK_INVALID_HANDLE)
247 continue;
248 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
249 GNTMAP_host_map, handle);
250 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
251 pages[invcount] = req->pages[i];
252 put_page(pages[invcount]);
253 invcount++;
254 if (invcount < VSCSI_GRANT_BATCH)
255 continue;
256 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
257 BUG_ON(err);
258 invcount = 0;
259 }
260
261 if (invcount) {
262 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
263 BUG_ON(err);
264 }
265
266 gnttab_page_cache_put(&req->info->free_pages, req->pages,
267 req->n_grants);
268 req->n_grants = 0;
269 }
270
271 static void scsiback_free_translation_entry(struct kref *kref)
272 {
273 struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
274 struct scsiback_tpg *tpg = entry->tpg;
275
276 mutex_lock(&tpg->tv_tpg_mutex);
277 tpg->tv_tpg_fe_count--;
278 mutex_unlock(&tpg->tv_tpg_mutex);
279
280 kfree(entry);
281 }
282
283 static int32_t scsiback_result(int32_t result)
284 {
285 int32_t host_status;
286
287 switch (XEN_VSCSIIF_RSLT_HOST(result)) {
288 case DID_OK:
289 host_status = XEN_VSCSIIF_RSLT_HOST_OK;
290 break;
291 case DID_NO_CONNECT:
292 host_status = XEN_VSCSIIF_RSLT_HOST_NO_CONNECT;
293 break;
294 case DID_BUS_BUSY:
295 host_status = XEN_VSCSIIF_RSLT_HOST_BUS_BUSY;
296 break;
297 case DID_TIME_OUT:
298 host_status = XEN_VSCSIIF_RSLT_HOST_TIME_OUT;
299 break;
300 case DID_BAD_TARGET:
301 host_status = XEN_VSCSIIF_RSLT_HOST_BAD_TARGET;
302 break;
303 case DID_ABORT:
304 host_status = XEN_VSCSIIF_RSLT_HOST_ABORT;
305 break;
306 case DID_PARITY:
307 host_status = XEN_VSCSIIF_RSLT_HOST_PARITY;
308 break;
309 case DID_ERROR:
310 host_status = XEN_VSCSIIF_RSLT_HOST_ERROR;
311 break;
312 case DID_RESET:
313 host_status = XEN_VSCSIIF_RSLT_HOST_RESET;
314 break;
315 case DID_BAD_INTR:
316 host_status = XEN_VSCSIIF_RSLT_HOST_BAD_INTR;
317 break;
318 case DID_PASSTHROUGH:
319 host_status = XEN_VSCSIIF_RSLT_HOST_PASSTHROUGH;
320 break;
321 case DID_SOFT_ERROR:
322 host_status = XEN_VSCSIIF_RSLT_HOST_SOFT_ERROR;
323 break;
324 case DID_IMM_RETRY:
325 host_status = XEN_VSCSIIF_RSLT_HOST_IMM_RETRY;
326 break;
327 case DID_REQUEUE:
328 host_status = XEN_VSCSIIF_RSLT_HOST_REQUEUE;
329 break;
330 case DID_TRANSPORT_DISRUPTED:
331 host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_DISRUPTED;
332 break;
333 case DID_TRANSPORT_FAILFAST:
334 host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_FAILFAST;
335 break;
336 case DID_TRANSPORT_MARGINAL:
337 host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL;
338 break;
339 default:
340 host_status = XEN_VSCSIIF_RSLT_HOST_ERROR;
341 break;
342 }
343
344 return (host_status << 16) | (result & 0x00ffff);
345 }
346
347 static void scsiback_send_response(struct vscsibk_info *info,
348 char *sense_buffer, int32_t result, uint32_t resid,
349 uint16_t rqid)
350 {
351 struct vscsiif_response *ring_res;
352 int notify;
353 struct scsi_sense_hdr sshdr;
354 unsigned long flags;
355 unsigned len;
356
357 spin_lock_irqsave(&info->ring_lock, flags);
358
359 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
360 info->ring.rsp_prod_pvt++;
361
362 ring_res->rslt = scsiback_result(result);
363 ring_res->rqid = rqid;
364
365 if (sense_buffer != NULL &&
366 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
367 &sshdr)) {
368 len = min_t(unsigned, 8 + sense_buffer[7],
369 VSCSIIF_SENSE_BUFFERSIZE);
370 memcpy(ring_res->sense_buffer, sense_buffer, len);
371 ring_res->sense_len = len;
372 } else {
373 ring_res->sense_len = 0;
374 }
375
376 ring_res->residual_len = resid;
377
378 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
379 spin_unlock_irqrestore(&info->ring_lock, flags);
380
381 if (notify)
382 notify_remote_via_irq(info->irq);
383 }
384
385 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
386 uint32_t resid, struct vscsibk_pend *pending_req)
387 {
388 scsiback_send_response(pending_req->info, sense_buffer, result,
389 resid, pending_req->rqid);
390
391 if (pending_req->v2p)
392 kref_put(&pending_req->v2p->kref,
393 scsiback_free_translation_entry);
394 }
395
396 static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
397 {
398 struct vscsibk_info *info = pending_req->info;
399 unsigned char *sense_buffer;
400 unsigned int resid;
401 int errors;
402
403 sense_buffer = pending_req->sense_buffer;
404 resid = pending_req->se_cmd.residual_count;
405 errors = pending_req->result;
406
407 if (errors && log_print_stat)
408 scsiback_print_status(sense_buffer, errors, pending_req);
409
410 scsiback_fast_flush_area(pending_req);
411 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
412 scsiback_put(info);
413 /*
414 * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls()
415 * ahead of scsiback_check_stop_free() -> transport_generic_free_cmd()
416 * final se_cmd->cmd_kref put.
417 */
418 target_put_sess_cmd(&pending_req->se_cmd);
419 }
420
421 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
422 {
423 struct se_cmd *se_cmd = &pending_req->se_cmd;
424 struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
425
426 scsiback_get(pending_req->info);
427 se_cmd->tag = pending_req->rqid;
428 target_init_cmd(se_cmd, sess, pending_req->sense_buffer,
429 pending_req->v2p->lun, pending_req->data_len, 0,
430 pending_req->sc_data_direction, TARGET_SCF_ACK_KREF);
431
432 if (target_submit_prep(se_cmd, pending_req->cmnd, pending_req->sgl,
433 pending_req->n_sg, NULL, 0, NULL, 0, GFP_KERNEL))
434 return;
435
436 target_submit(se_cmd);
437 }
438
439 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
440 struct page **pg, grant_handle_t *grant, int cnt)
441 {
442 int err, i;
443
444 if (!cnt)
445 return 0;
446
447 err = gnttab_map_refs(map, NULL, pg, cnt);
448 for (i = 0; i < cnt; i++) {
449 if (unlikely(map[i].status != GNTST_okay)) {
450 pr_err("invalid buffer -- could not remap it\n");
451 map[i].handle = SCSIBACK_INVALID_HANDLE;
452 if (!err)
453 err = -ENOMEM;
454 } else {
455 get_page(pg[i]);
456 }
457 grant[i] = map[i].handle;
458 }
459 return err;
460 }
461
462 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
463 struct scsiif_request_segment *seg, struct page **pg,
464 grant_handle_t *grant, int cnt, u32 flags)
465 {
466 int mapcount = 0, i, err = 0;
467 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
468 struct vscsibk_info *info = pending_req->info;
469
470 for (i = 0; i < cnt; i++) {
471 if (gnttab_page_cache_get(&info->free_pages, pg + mapcount)) {
472 gnttab_page_cache_put(&info->free_pages, pg, mapcount);
473 pr_err("no grant page\n");
474 return -ENOMEM;
475 }
476 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
477 flags, seg[i].gref, info->domid);
478 mapcount++;
479 if (mapcount < VSCSI_GRANT_BATCH)
480 continue;
481 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
482 pg += mapcount;
483 grant += mapcount;
484 pending_req->n_grants += mapcount;
485 if (err)
486 return err;
487 mapcount = 0;
488 }
489 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
490 pending_req->n_grants += mapcount;
491 return err;
492 }
493
494 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
495 struct vscsibk_pend *pending_req)
496 {
497 u32 flags;
498 int i, err, n_segs, i_seg = 0;
499 struct page **pg;
500 struct scsiif_request_segment *seg;
501 unsigned long end_seg = 0;
502 unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
503 unsigned int nr_sgl = 0;
504 struct scatterlist *sg;
505 grant_handle_t *grant;
506
507 pending_req->n_sg = 0;
508 pending_req->n_grants = 0;
509 pending_req->data_len = 0;
510
511 nr_segments &= ~VSCSIIF_SG_GRANT;
512 if (!nr_segments)
513 return 0;
514
515 if (nr_segments > VSCSIIF_SG_TABLESIZE) {
516 pr_debug("invalid parameter nr_seg = %d\n",
517 ring_req->nr_segments);
518 return -EINVAL;
519 }
520
521 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
522 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
523 pending_req->pages, pending_req->grant_handles,
524 nr_segments, GNTMAP_host_map | GNTMAP_readonly);
525 if (err)
526 return err;
527 nr_sgl = nr_segments;
528 nr_segments = 0;
529 for (i = 0; i < nr_sgl; i++) {
530 n_segs = ring_req->seg[i].length /
531 sizeof(struct scsiif_request_segment);
532 if ((unsigned)ring_req->seg[i].offset +
533 (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
534 n_segs * sizeof(struct scsiif_request_segment) !=
535 ring_req->seg[i].length)
536 return -EINVAL;
537 nr_segments += n_segs;
538 }
539 if (nr_segments > SG_ALL) {
540 pr_debug("invalid nr_seg = %d\n", nr_segments);
541 return -EINVAL;
542 }
543 }
544
545 /* free of (sgl) in fast_flush_area() */
546 pending_req->sgl = kmalloc_array(nr_segments,
547 sizeof(struct scatterlist), GFP_KERNEL);
548 if (!pending_req->sgl)
549 return -ENOMEM;
550
551 sg_init_table(pending_req->sgl, nr_segments);
552 pending_req->n_sg = nr_segments;
553
554 flags = GNTMAP_host_map;
555 if (pending_req->sc_data_direction == DMA_TO_DEVICE)
556 flags |= GNTMAP_readonly;
557
558 pg = pending_req->pages + nr_sgl;
559 grant = pending_req->grant_handles + nr_sgl;
560 if (!nr_sgl) {
561 seg = ring_req->seg;
562 err = scsiback_gnttab_data_map_list(pending_req, seg,
563 pg, grant, nr_segments, flags);
564 if (err)
565 return err;
566 } else {
567 for (i = 0; i < nr_sgl; i++) {
568 seg = (struct scsiif_request_segment *)(
569 vaddr(pending_req, i) + ring_req->seg[i].offset);
570 n_segs = ring_req->seg[i].length /
571 sizeof(struct scsiif_request_segment);
572 err = scsiback_gnttab_data_map_list(pending_req, seg,
573 pg, grant, n_segs, flags);
574 if (err)
575 return err;
576 pg += n_segs;
577 grant += n_segs;
578 }
579 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
580 seg = (struct scsiif_request_segment *)end_seg;
581 end_seg += ring_req->seg[0].length;
582 pg = pending_req->pages + nr_sgl;
583 }
584
585 for_each_sg(pending_req->sgl, sg, nr_segments, i) {
586 sg_set_page(sg, pg[i], seg->length, seg->offset);
587 pending_req->data_len += seg->length;
588 seg++;
589 if (nr_sgl && (unsigned long)seg >= end_seg) {
590 i_seg++;
591 end_seg = vaddr(pending_req, i_seg) +
592 ring_req->seg[i_seg].offset;
593 seg = (struct scsiif_request_segment *)end_seg;
594 end_seg += ring_req->seg[i_seg].length;
595 }
596 if (sg->offset >= PAGE_SIZE ||
597 sg->length > PAGE_SIZE ||
598 sg->offset + sg->length > PAGE_SIZE)
599 return -EINVAL;
600 }
601
602 return 0;
603 }
604
605 static void scsiback_disconnect(struct vscsibk_info *info)
606 {
607 wait_event(info->waiting_to_free,
608 atomic_read(&info->nr_unreplied_reqs) == 0);
609
610 unbind_from_irqhandler(info->irq, info);
611 info->irq = 0;
612 xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
613 }
614
615 static void scsiback_device_action(struct vscsibk_pend *pending_req,
616 enum tcm_tmreq_table act, int tag)
617 {
618 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
619 struct scsiback_nexus *nexus = tpg->tpg_nexus;
620 struct se_cmd *se_cmd = &pending_req->se_cmd;
621 u64 unpacked_lun = pending_req->v2p->lun;
622 int rc, err = XEN_VSCSIIF_RSLT_RESET_FAILED;
623
624 init_completion(&pending_req->tmr_done);
625
626 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess,
627 &pending_req->sense_buffer[0],
628 unpacked_lun, NULL, act, GFP_KERNEL,
629 tag, TARGET_SCF_ACK_KREF);
630 if (rc)
631 goto err;
632
633 wait_for_completion(&pending_req->tmr_done);
634
635 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
636 XEN_VSCSIIF_RSLT_RESET_SUCCESS : XEN_VSCSIIF_RSLT_RESET_FAILED;
637
638 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
639 transport_generic_free_cmd(&pending_req->se_cmd, 0);
640 return;
641
642 err:
643 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
644 }
645
646 /*
647 Perform virtual to physical translation
648 */
649 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
650 struct ids_tuple *v)
651 {
652 struct v2p_entry *entry;
653 struct list_head *head = &(info->v2p_entry_lists);
654 unsigned long flags;
655
656 spin_lock_irqsave(&info->v2p_lock, flags);
657 list_for_each_entry(entry, head, l) {
658 if ((entry->v.chn == v->chn) &&
659 (entry->v.tgt == v->tgt) &&
660 (entry->v.lun == v->lun)) {
661 kref_get(&entry->kref);
662 goto out;
663 }
664 }
665 entry = NULL;
666
667 out:
668 spin_unlock_irqrestore(&info->v2p_lock, flags);
669 return entry;
670 }
671
672 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring,
673 struct v2p_entry *v2p)
674 {
675 struct scsiback_tpg *tpg = v2p->tpg;
676 struct scsiback_nexus *nexus = tpg->tpg_nexus;
677 struct se_session *se_sess = nexus->tvn_se_sess;
678 struct vscsibk_pend *req;
679 int tag, cpu, i;
680
681 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
682 if (tag < 0) {
683 pr_err("Unable to obtain tag for vscsiif_request\n");
684 return ERR_PTR(-ENOMEM);
685 }
686
687 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
688 memset(req, 0, sizeof(*req));
689 req->se_cmd.map_tag = tag;
690 req->se_cmd.map_cpu = cpu;
691
692 for (i = 0; i < VSCSI_MAX_GRANTS; i++)
693 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
694
695 return req;
696 }
697
698 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
699 struct vscsiif_back_ring *ring,
700 struct vscsiif_request *ring_req)
701 {
702 struct vscsibk_pend *pending_req;
703 struct v2p_entry *v2p;
704 struct ids_tuple vir;
705
706 /* request range check from frontend */
707 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
708 (ring_req->sc_data_direction != DMA_TO_DEVICE) &&
709 (ring_req->sc_data_direction != DMA_FROM_DEVICE) &&
710 (ring_req->sc_data_direction != DMA_NONE)) {
711 pr_debug("invalid parameter data_dir = %d\n",
712 ring_req->sc_data_direction);
713 return ERR_PTR(-EINVAL);
714 }
715 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
716 pr_debug("invalid parameter cmd_len = %d\n",
717 ring_req->cmd_len);
718 return ERR_PTR(-EINVAL);
719 }
720
721 vir.chn = ring_req->channel;
722 vir.tgt = ring_req->id;
723 vir.lun = ring_req->lun;
724
725 v2p = scsiback_do_translation(info, &vir);
726 if (!v2p) {
727 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
728 vir.chn, vir.tgt, vir.lun);
729 return ERR_PTR(-ENODEV);
730 }
731
732 pending_req = scsiback_get_pend_req(ring, v2p);
733 if (IS_ERR(pending_req)) {
734 kref_put(&v2p->kref, scsiback_free_translation_entry);
735 return ERR_PTR(-ENOMEM);
736 }
737 pending_req->rqid = ring_req->rqid;
738 pending_req->info = info;
739 pending_req->v2p = v2p;
740 pending_req->sc_data_direction = ring_req->sc_data_direction;
741 pending_req->cmd_len = ring_req->cmd_len;
742 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
743
744 return pending_req;
745 }
746
747 static int scsiback_do_cmd_fn(struct vscsibk_info *info,
748 unsigned int *eoi_flags)
749 {
750 struct vscsiif_back_ring *ring = &info->ring;
751 struct vscsiif_request ring_req;
752 struct vscsibk_pend *pending_req;
753 RING_IDX rc, rp;
754 int more_to_do;
755 uint32_t result;
756
757 rc = ring->req_cons;
758 rp = ring->sring->req_prod;
759 rmb(); /* guest system is accessing ring, too */
760
761 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
762 rc = ring->rsp_prod_pvt;
763 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
764 info->domid, rp, rc, rp - rc);
765 return -EINVAL;
766 }
767
768 while ((rc != rp)) {
769 *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
770
771 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
772 break;
773
774 RING_COPY_REQUEST(ring, rc, &ring_req);
775 ring->req_cons = ++rc;
776
777 pending_req = prepare_pending_reqs(info, ring, &ring_req);
778 if (IS_ERR(pending_req)) {
779 switch (PTR_ERR(pending_req)) {
780 case -ENODEV:
781 result = DID_NO_CONNECT;
782 break;
783 default:
784 result = DID_ERROR;
785 break;
786 }
787 scsiback_send_response(info, NULL, result << 16, 0,
788 ring_req.rqid);
789 return 1;
790 }
791
792 switch (ring_req.act) {
793 case VSCSIIF_ACT_SCSI_CDB:
794 if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
795 scsiback_fast_flush_area(pending_req);
796 scsiback_do_resp_with_sense(NULL,
797 DID_ERROR << 16, 0, pending_req);
798 transport_generic_free_cmd(&pending_req->se_cmd, 0);
799 } else {
800 scsiback_cmd_exec(pending_req);
801 }
802 break;
803 case VSCSIIF_ACT_SCSI_ABORT:
804 scsiback_device_action(pending_req, TMR_ABORT_TASK,
805 ring_req.ref_rqid);
806 break;
807 case VSCSIIF_ACT_SCSI_RESET:
808 scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
809 break;
810 default:
811 pr_err_ratelimited("invalid request\n");
812 scsiback_do_resp_with_sense(NULL, DID_ERROR << 16, 0,
813 pending_req);
814 transport_generic_free_cmd(&pending_req->se_cmd, 0);
815 break;
816 }
817
818 /* Yield point for this unbounded loop. */
819 cond_resched();
820 }
821
822 gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages);
823
824 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
825 return more_to_do;
826 }
827
828 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
829 {
830 struct vscsibk_info *info = dev_id;
831 int rc;
832 unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
833
834 while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0)
835 cond_resched();
836
837 /* In case of a ring error we keep the event channel masked. */
838 if (!rc)
839 xen_irq_lateeoi(irq, eoi_flags);
840
841 return IRQ_HANDLED;
842 }
843
844 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
845 evtchn_port_t evtchn)
846 {
847 void *area;
848 struct vscsiif_sring *sring;
849 int err;
850
851 if (info->irq)
852 return -1;
853
854 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
855 if (err)
856 return err;
857
858 sring = (struct vscsiif_sring *)area;
859 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
860
861 err = bind_interdomain_evtchn_to_irq_lateeoi(info->dev, evtchn);
862 if (err < 0)
863 goto unmap_page;
864
865 info->irq = err;
866
867 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
868 IRQF_ONESHOT, "vscsiif-backend", info);
869 if (err)
870 goto free_irq;
871
872 return 0;
873
874 free_irq:
875 unbind_from_irqhandler(info->irq, info);
876 info->irq = 0;
877 unmap_page:
878 xenbus_unmap_ring_vfree(info->dev, area);
879
880 return err;
881 }
882
883 static int scsiback_map(struct vscsibk_info *info)
884 {
885 struct xenbus_device *dev = info->dev;
886 unsigned int ring_ref;
887 evtchn_port_t evtchn;
888 int err;
889
890 err = xenbus_gather(XBT_NIL, dev->otherend,
891 "ring-ref", "%u", &ring_ref,
892 "event-channel", "%u", &evtchn, NULL);
893 if (err) {
894 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
895 return err;
896 }
897
898 return scsiback_init_sring(info, ring_ref, evtchn);
899 }
900
901 /*
902 Check for a translation entry being present
903 */
904 static struct v2p_entry *scsiback_chk_translation_entry(
905 struct vscsibk_info *info, struct ids_tuple *v)
906 {
907 struct list_head *head = &(info->v2p_entry_lists);
908 struct v2p_entry *entry;
909
910 list_for_each_entry(entry, head, l)
911 if ((entry->v.chn == v->chn) &&
912 (entry->v.tgt == v->tgt) &&
913 (entry->v.lun == v->lun))
914 return entry;
915
916 return NULL;
917 }
918
919 /*
920 Add a new translation entry
921 */
922 static int scsiback_add_translation_entry(struct vscsibk_info *info,
923 char *phy, struct ids_tuple *v)
924 {
925 int err = 0;
926 struct v2p_entry *new;
927 unsigned long flags;
928 char *lunp;
929 unsigned long long unpacked_lun;
930 struct se_lun *se_lun;
931 struct scsiback_tpg *tpg_entry, *tpg = NULL;
932 char *error = "doesn't exist";
933
934 lunp = strrchr(phy, ':');
935 if (!lunp) {
936 pr_err("illegal format of physical device %s\n", phy);
937 return -EINVAL;
938 }
939 *lunp = 0;
940 lunp++;
941 err = kstrtoull(lunp, 10, &unpacked_lun);
942 if (err < 0) {
943 pr_err("lun number not valid: %s\n", lunp);
944 return err;
945 }
946
947 mutex_lock(&scsiback_mutex);
948 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
949 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
950 !strcmp(phy, tpg_entry->param_alias)) {
951 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex);
952 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) {
953 if (se_lun->unpacked_lun == unpacked_lun) {
954 if (!tpg_entry->tpg_nexus)
955 error = "nexus undefined";
956 else
957 tpg = tpg_entry;
958 break;
959 }
960 }
961 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex);
962 break;
963 }
964 }
965 if (tpg) {
966 mutex_lock(&tpg->tv_tpg_mutex);
967 tpg->tv_tpg_fe_count++;
968 mutex_unlock(&tpg->tv_tpg_mutex);
969 }
970 mutex_unlock(&scsiback_mutex);
971
972 if (!tpg) {
973 pr_err("%s:%llu %s\n", phy, unpacked_lun, error);
974 return -ENODEV;
975 }
976
977 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
978 if (new == NULL) {
979 err = -ENOMEM;
980 goto out_free;
981 }
982
983 spin_lock_irqsave(&info->v2p_lock, flags);
984
985 /* Check double assignment to identical virtual ID */
986 if (scsiback_chk_translation_entry(info, v)) {
987 pr_warn("Virtual ID is already used. Assignment was not performed.\n");
988 err = -EEXIST;
989 goto out;
990 }
991
992 /* Create a new translation entry and add to the list */
993 kref_init(&new->kref);
994 new->v = *v;
995 new->tpg = tpg;
996 new->lun = unpacked_lun;
997 list_add_tail(&new->l, &info->v2p_entry_lists);
998
999 out:
1000 spin_unlock_irqrestore(&info->v2p_lock, flags);
1001
1002 out_free:
1003 if (err) {
1004 mutex_lock(&tpg->tv_tpg_mutex);
1005 tpg->tv_tpg_fe_count--;
1006 mutex_unlock(&tpg->tv_tpg_mutex);
1007 kfree(new);
1008 }
1009
1010 return err;
1011 }
1012
1013 /*
1014 Delete the translation entry specified
1015 */
1016 static int scsiback_del_translation_entry(struct vscsibk_info *info,
1017 struct ids_tuple *v)
1018 {
1019 struct v2p_entry *entry;
1020 unsigned long flags;
1021
1022 spin_lock_irqsave(&info->v2p_lock, flags);
1023 /* Find out the translation entry specified */
1024 entry = scsiback_chk_translation_entry(info, v);
1025 if (entry)
1026 list_del(&entry->l);
1027
1028 spin_unlock_irqrestore(&info->v2p_lock, flags);
1029
1030 if (!entry)
1031 return -ENOENT;
1032
1033 kref_put(&entry->kref, scsiback_free_translation_entry);
1034 return 0;
1035 }
1036
1037 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
1038 char *phy, struct ids_tuple *vir, int try)
1039 {
1040 struct v2p_entry *entry;
1041 unsigned long flags;
1042 int err;
1043
1044 if (try) {
1045 spin_lock_irqsave(&info->v2p_lock, flags);
1046 entry = scsiback_chk_translation_entry(info, vir);
1047 spin_unlock_irqrestore(&info->v2p_lock, flags);
1048 if (entry)
1049 return;
1050 }
1051 if (!scsiback_add_translation_entry(info, phy, vir)) {
1052 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1053 "%d", XenbusStateInitialised)) {
1054 pr_err("xenbus_printf error %s\n", state);
1055 scsiback_del_translation_entry(info, vir);
1056 }
1057 } else if (!try) {
1058 err = xenbus_printf(XBT_NIL, info->dev->nodename, state,
1059 "%d", XenbusStateClosed);
1060 if (err)
1061 xenbus_dev_error(info->dev, err,
1062 "%s: writing %s", __func__, state);
1063 }
1064 }
1065
1066 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1067 struct ids_tuple *vir)
1068 {
1069 if (!scsiback_del_translation_entry(info, vir)) {
1070 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1071 "%d", XenbusStateClosed))
1072 pr_err("xenbus_printf error %s\n", state);
1073 }
1074 }
1075
1076 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1
1077 #define VSCSIBACK_OP_UPDATEDEV_STATE 2
1078
1079 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1080 char *ent)
1081 {
1082 int err;
1083 struct ids_tuple vir;
1084 char *val;
1085 int device_state;
1086 char phy[VSCSI_NAMELEN];
1087 char str[64];
1088 char state[64];
1089 struct xenbus_device *dev = info->dev;
1090
1091 /* read status */
1092 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1093 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1094 if (XENBUS_EXIST_ERR(err))
1095 return;
1096
1097 /* physical SCSI device */
1098 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1099 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1100 if (IS_ERR(val)) {
1101 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1102 "%d", XenbusStateClosed);
1103 if (err)
1104 xenbus_dev_error(info->dev, err,
1105 "%s: writing %s", __func__, state);
1106 return;
1107 }
1108 strscpy(phy, val, VSCSI_NAMELEN);
1109 kfree(val);
1110
1111 /* virtual SCSI device */
1112 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1113 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1114 &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1115 if (XENBUS_EXIST_ERR(err)) {
1116 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1117 "%d", XenbusStateClosed);
1118 if (err)
1119 xenbus_dev_error(info->dev, err,
1120 "%s: writing %s", __func__, state);
1121 return;
1122 }
1123
1124 switch (op) {
1125 case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1126 switch (device_state) {
1127 case XenbusStateInitialising:
1128 scsiback_do_add_lun(info, state, phy, &vir, 0);
1129 break;
1130 case XenbusStateConnected:
1131 scsiback_do_add_lun(info, state, phy, &vir, 1);
1132 break;
1133 case XenbusStateClosing:
1134 scsiback_do_del_lun(info, state, &vir);
1135 break;
1136 default:
1137 break;
1138 }
1139 break;
1140
1141 case VSCSIBACK_OP_UPDATEDEV_STATE:
1142 if (device_state == XenbusStateInitialised) {
1143 /* modify vscsi-devs/dev-x/state */
1144 if (xenbus_printf(XBT_NIL, dev->nodename, state,
1145 "%d", XenbusStateConnected)) {
1146 pr_err("xenbus_printf error %s\n", str);
1147 scsiback_del_translation_entry(info, &vir);
1148 xenbus_printf(XBT_NIL, dev->nodename, state,
1149 "%d", XenbusStateClosed);
1150 }
1151 }
1152 break;
1153 /* When it is necessary, processing is added here. */
1154 default:
1155 break;
1156 }
1157 }
1158
1159 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1160 {
1161 int i;
1162 char **dir;
1163 unsigned int ndir = 0;
1164
1165 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1166 &ndir);
1167 if (IS_ERR(dir))
1168 return;
1169
1170 for (i = 0; i < ndir; i++)
1171 scsiback_do_1lun_hotplug(info, op, dir[i]);
1172
1173 kfree(dir);
1174 }
1175
1176 static void scsiback_frontend_changed(struct xenbus_device *dev,
1177 enum xenbus_state frontend_state)
1178 {
1179 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1180
1181 switch (frontend_state) {
1182 case XenbusStateInitialising:
1183 break;
1184
1185 case XenbusStateInitialised:
1186 if (scsiback_map(info))
1187 break;
1188
1189 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1190 xenbus_switch_state(dev, XenbusStateConnected);
1191 break;
1192
1193 case XenbusStateConnected:
1194 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1195
1196 if (dev->state == XenbusStateConnected)
1197 break;
1198
1199 xenbus_switch_state(dev, XenbusStateConnected);
1200 break;
1201
1202 case XenbusStateClosing:
1203 if (info->irq)
1204 scsiback_disconnect(info);
1205
1206 xenbus_switch_state(dev, XenbusStateClosing);
1207 break;
1208
1209 case XenbusStateClosed:
1210 xenbus_switch_state(dev, XenbusStateClosed);
1211 if (xenbus_dev_is_online(dev))
1212 break;
1213 fallthrough; /* if not online */
1214 case XenbusStateUnknown:
1215 device_unregister(&dev->dev);
1216 break;
1217
1218 case XenbusStateReconfiguring:
1219 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1220 xenbus_switch_state(dev, XenbusStateReconfigured);
1221
1222 break;
1223
1224 default:
1225 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1226 frontend_state);
1227 break;
1228 }
1229 }
1230
1231 /*
1232 Release the translation entry specfied
1233 */
1234 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1235 {
1236 struct v2p_entry *entry, *tmp;
1237 struct list_head *head = &(info->v2p_entry_lists);
1238 struct list_head tmp_list;
1239 unsigned long flags;
1240
1241 spin_lock_irqsave(&info->v2p_lock, flags);
1242
1243 list_cut_before(&tmp_list, head, head);
1244
1245 spin_unlock_irqrestore(&info->v2p_lock, flags);
1246
1247 list_for_each_entry_safe(entry, tmp, &tmp_list, l) {
1248 list_del(&entry->l);
1249 kref_put(&entry->kref, scsiback_free_translation_entry);
1250 }
1251 }
1252
1253 static void scsiback_remove(struct xenbus_device *dev)
1254 {
1255 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1256
1257 if (info->irq)
1258 scsiback_disconnect(info);
1259
1260 scsiback_release_translation_entry(info);
1261
1262 gnttab_page_cache_shrink(&info->free_pages, 0);
1263
1264 dev_set_drvdata(&dev->dev, NULL);
1265 }
1266
1267 static int scsiback_probe(struct xenbus_device *dev,
1268 const struct xenbus_device_id *id)
1269 {
1270 int err;
1271
1272 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1273 GFP_KERNEL);
1274
1275 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
1276
1277 if (!info) {
1278 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1279 return -ENOMEM;
1280 }
1281 info->dev = dev;
1282 dev_set_drvdata(&dev->dev, info);
1283
1284 info->domid = dev->otherend_id;
1285 spin_lock_init(&info->ring_lock);
1286 atomic_set(&info->nr_unreplied_reqs, 0);
1287 init_waitqueue_head(&info->waiting_to_free);
1288 info->dev = dev;
1289 info->irq = 0;
1290 INIT_LIST_HEAD(&info->v2p_entry_lists);
1291 spin_lock_init(&info->v2p_lock);
1292 gnttab_page_cache_init(&info->free_pages);
1293
1294 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1295 SG_ALL);
1296 if (err)
1297 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1298
1299 err = xenbus_switch_state(dev, XenbusStateInitWait);
1300 if (err)
1301 goto fail;
1302
1303 return 0;
1304
1305 fail:
1306 pr_warn("%s failed\n", __func__);
1307 scsiback_remove(dev);
1308
1309 return err;
1310 }
1311
1312 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1313 {
1314 switch (tport->tport_proto_id) {
1315 case SCSI_PROTOCOL_SAS:
1316 return "SAS";
1317 case SCSI_PROTOCOL_FCP:
1318 return "FCP";
1319 case SCSI_PROTOCOL_ISCSI:
1320 return "iSCSI";
1321 default:
1322 break;
1323 }
1324
1325 return "Unknown";
1326 }
1327
1328 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1329 {
1330 struct scsiback_tpg *tpg = container_of(se_tpg,
1331 struct scsiback_tpg, se_tpg);
1332 struct scsiback_tport *tport = tpg->tport;
1333
1334 return &tport->tport_name[0];
1335 }
1336
1337 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1338 {
1339 struct scsiback_tpg *tpg = container_of(se_tpg,
1340 struct scsiback_tpg, se_tpg);
1341 return tpg->tport_tpgt;
1342 }
1343
1344 static struct se_wwn *
1345 scsiback_make_tport(struct target_fabric_configfs *tf,
1346 struct config_group *group,
1347 const char *name)
1348 {
1349 struct scsiback_tport *tport;
1350 char *ptr;
1351 u64 wwpn = 0;
1352 int off = 0;
1353
1354 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1355 if (!tport)
1356 return ERR_PTR(-ENOMEM);
1357
1358 tport->tport_wwpn = wwpn;
1359 /*
1360 * Determine the emulated Protocol Identifier and Target Port Name
1361 * based on the incoming configfs directory name.
1362 */
1363 ptr = strstr(name, "naa.");
1364 if (ptr) {
1365 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1366 goto check_len;
1367 }
1368 ptr = strstr(name, "fc.");
1369 if (ptr) {
1370 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1371 off = 3; /* Skip over "fc." */
1372 goto check_len;
1373 }
1374 ptr = strstr(name, "iqn.");
1375 if (ptr) {
1376 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1377 goto check_len;
1378 }
1379
1380 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1381 kfree(tport);
1382 return ERR_PTR(-EINVAL);
1383
1384 check_len:
1385 if (strlen(name) >= VSCSI_NAMELEN) {
1386 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1387 scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1388 kfree(tport);
1389 return ERR_PTR(-EINVAL);
1390 }
1391 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1392
1393 pr_debug("Allocated emulated Target %s Address: %s\n",
1394 scsiback_dump_proto_id(tport), name);
1395
1396 return &tport->tport_wwn;
1397 }
1398
1399 static void scsiback_drop_tport(struct se_wwn *wwn)
1400 {
1401 struct scsiback_tport *tport = container_of(wwn,
1402 struct scsiback_tport, tport_wwn);
1403
1404 pr_debug("Deallocating emulated Target %s Address: %s\n",
1405 scsiback_dump_proto_id(tport), tport->tport_name);
1406
1407 kfree(tport);
1408 }
1409
1410 static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1411 {
1412 return transport_generic_free_cmd(se_cmd, 0);
1413 }
1414
1415 static void scsiback_release_cmd(struct se_cmd *se_cmd)
1416 {
1417 target_free_tag(se_cmd->se_sess, se_cmd);
1418 }
1419
1420 static int scsiback_write_pending(struct se_cmd *se_cmd)
1421 {
1422 /* Go ahead and process the write immediately */
1423 target_execute_cmd(se_cmd);
1424
1425 return 0;
1426 }
1427
1428 static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1429 {
1430 struct vscsibk_pend *pending_req = container_of(se_cmd,
1431 struct vscsibk_pend, se_cmd);
1432
1433 pending_req->result = SAM_STAT_GOOD;
1434 scsiback_cmd_done(pending_req);
1435 return 0;
1436 }
1437
1438 static int scsiback_queue_status(struct se_cmd *se_cmd)
1439 {
1440 struct vscsibk_pend *pending_req = container_of(se_cmd,
1441 struct vscsibk_pend, se_cmd);
1442
1443 if (se_cmd->sense_buffer &&
1444 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1445 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1446 pending_req->result = SAM_STAT_CHECK_CONDITION;
1447 else
1448 pending_req->result = se_cmd->scsi_status;
1449
1450 scsiback_cmd_done(pending_req);
1451 return 0;
1452 }
1453
1454 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1455 {
1456 struct vscsibk_pend *pending_req = container_of(se_cmd,
1457 struct vscsibk_pend, se_cmd);
1458
1459 complete(&pending_req->tmr_done);
1460 }
1461
1462 static void scsiback_aborted_task(struct se_cmd *se_cmd)
1463 {
1464 }
1465
1466 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item,
1467 char *page)
1468 {
1469 struct se_portal_group *se_tpg = param_to_tpg(item);
1470 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1471 se_tpg);
1472 ssize_t rb;
1473
1474 mutex_lock(&tpg->tv_tpg_mutex);
1475 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1476 mutex_unlock(&tpg->tv_tpg_mutex);
1477
1478 return rb;
1479 }
1480
1481 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item,
1482 const char *page, size_t count)
1483 {
1484 struct se_portal_group *se_tpg = param_to_tpg(item);
1485 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1486 se_tpg);
1487 int len;
1488
1489 if (strlen(page) >= VSCSI_NAMELEN) {
1490 pr_err("param alias: %s, exceeds max: %d\n", page,
1491 VSCSI_NAMELEN);
1492 return -EINVAL;
1493 }
1494
1495 mutex_lock(&tpg->tv_tpg_mutex);
1496 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1497 if (tpg->param_alias[len - 1] == '\n')
1498 tpg->param_alias[len - 1] = '\0';
1499 mutex_unlock(&tpg->tv_tpg_mutex);
1500
1501 return count;
1502 }
1503
1504 CONFIGFS_ATTR(scsiback_tpg_param_, alias);
1505
1506 static struct configfs_attribute *scsiback_param_attrs[] = {
1507 &scsiback_tpg_param_attr_alias,
1508 NULL,
1509 };
1510
1511 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg,
1512 struct se_session *se_sess, void *p)
1513 {
1514 struct scsiback_tpg *tpg = container_of(se_tpg,
1515 struct scsiback_tpg, se_tpg);
1516
1517 tpg->tpg_nexus = p;
1518 return 0;
1519 }
1520
1521 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1522 const char *name)
1523 {
1524 struct scsiback_nexus *tv_nexus;
1525 int ret = 0;
1526
1527 mutex_lock(&tpg->tv_tpg_mutex);
1528 if (tpg->tpg_nexus) {
1529 pr_debug("tpg->tpg_nexus already exists\n");
1530 ret = -EEXIST;
1531 goto out_unlock;
1532 }
1533
1534 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1535 if (!tv_nexus) {
1536 ret = -ENOMEM;
1537 goto out_unlock;
1538 }
1539
1540 tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
1541 VSCSI_DEFAULT_SESSION_TAGS,
1542 sizeof(struct vscsibk_pend),
1543 TARGET_PROT_NORMAL, name,
1544 tv_nexus, scsiback_alloc_sess_cb);
1545 if (IS_ERR(tv_nexus->tvn_se_sess)) {
1546 kfree(tv_nexus);
1547 ret = -ENOMEM;
1548 goto out_unlock;
1549 }
1550
1551 out_unlock:
1552 mutex_unlock(&tpg->tv_tpg_mutex);
1553 return ret;
1554 }
1555
1556 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1557 {
1558 struct se_session *se_sess;
1559 struct scsiback_nexus *tv_nexus;
1560
1561 mutex_lock(&tpg->tv_tpg_mutex);
1562 tv_nexus = tpg->tpg_nexus;
1563 if (!tv_nexus) {
1564 mutex_unlock(&tpg->tv_tpg_mutex);
1565 return -ENODEV;
1566 }
1567
1568 se_sess = tv_nexus->tvn_se_sess;
1569 if (!se_sess) {
1570 mutex_unlock(&tpg->tv_tpg_mutex);
1571 return -ENODEV;
1572 }
1573
1574 if (tpg->tv_tpg_port_count != 0) {
1575 mutex_unlock(&tpg->tv_tpg_mutex);
1576 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1577 tpg->tv_tpg_port_count);
1578 return -EBUSY;
1579 }
1580
1581 if (tpg->tv_tpg_fe_count != 0) {
1582 mutex_unlock(&tpg->tv_tpg_mutex);
1583 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1584 tpg->tv_tpg_fe_count);
1585 return -EBUSY;
1586 }
1587
1588 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1589 scsiback_dump_proto_id(tpg->tport),
1590 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1591
1592 /*
1593 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1594 */
1595 target_remove_session(se_sess);
1596 tpg->tpg_nexus = NULL;
1597 mutex_unlock(&tpg->tv_tpg_mutex);
1598
1599 kfree(tv_nexus);
1600 return 0;
1601 }
1602
1603 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page)
1604 {
1605 struct se_portal_group *se_tpg = to_tpg(item);
1606 struct scsiback_tpg *tpg = container_of(se_tpg,
1607 struct scsiback_tpg, se_tpg);
1608 struct scsiback_nexus *tv_nexus;
1609 ssize_t ret;
1610
1611 mutex_lock(&tpg->tv_tpg_mutex);
1612 tv_nexus = tpg->tpg_nexus;
1613 if (!tv_nexus) {
1614 mutex_unlock(&tpg->tv_tpg_mutex);
1615 return -ENODEV;
1616 }
1617 ret = snprintf(page, PAGE_SIZE, "%s\n",
1618 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1619 mutex_unlock(&tpg->tv_tpg_mutex);
1620
1621 return ret;
1622 }
1623
1624 static ssize_t scsiback_tpg_nexus_store(struct config_item *item,
1625 const char *page, size_t count)
1626 {
1627 struct se_portal_group *se_tpg = to_tpg(item);
1628 struct scsiback_tpg *tpg = container_of(se_tpg,
1629 struct scsiback_tpg, se_tpg);
1630 struct scsiback_tport *tport_wwn = tpg->tport;
1631 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1632 int ret;
1633 /*
1634 * Shutdown the active I_T nexus if 'NULL' is passed.
1635 */
1636 if (!strncmp(page, "NULL", 4)) {
1637 ret = scsiback_drop_nexus(tpg);
1638 return (!ret) ? count : ret;
1639 }
1640 /*
1641 * Otherwise make sure the passed virtual Initiator port WWN matches
1642 * the fabric protocol_id set in scsiback_make_tport(), and call
1643 * scsiback_make_nexus().
1644 */
1645 if (strlen(page) >= VSCSI_NAMELEN) {
1646 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1647 page, VSCSI_NAMELEN);
1648 return -EINVAL;
1649 }
1650 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1651
1652 ptr = strstr(i_port, "naa.");
1653 if (ptr) {
1654 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1655 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1656 i_port, scsiback_dump_proto_id(tport_wwn));
1657 return -EINVAL;
1658 }
1659 port_ptr = &i_port[0];
1660 goto check_newline;
1661 }
1662 ptr = strstr(i_port, "fc.");
1663 if (ptr) {
1664 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1665 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1666 i_port, scsiback_dump_proto_id(tport_wwn));
1667 return -EINVAL;
1668 }
1669 port_ptr = &i_port[3]; /* Skip over "fc." */
1670 goto check_newline;
1671 }
1672 ptr = strstr(i_port, "iqn.");
1673 if (ptr) {
1674 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1675 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1676 i_port, scsiback_dump_proto_id(tport_wwn));
1677 return -EINVAL;
1678 }
1679 port_ptr = &i_port[0];
1680 goto check_newline;
1681 }
1682 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1683 i_port);
1684 return -EINVAL;
1685 /*
1686 * Clear any trailing newline for the NAA WWN
1687 */
1688 check_newline:
1689 if (i_port[strlen(i_port) - 1] == '\n')
1690 i_port[strlen(i_port) - 1] = '\0';
1691
1692 ret = scsiback_make_nexus(tpg, port_ptr);
1693 if (ret < 0)
1694 return ret;
1695
1696 return count;
1697 }
1698
1699 CONFIGFS_ATTR(scsiback_tpg_, nexus);
1700
1701 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1702 &scsiback_tpg_attr_nexus,
1703 NULL,
1704 };
1705
1706 static ssize_t
1707 scsiback_wwn_version_show(struct config_item *item, char *page)
1708 {
1709 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1710 UTS_RELEASE"\n",
1711 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1712 }
1713
1714 CONFIGFS_ATTR_RO(scsiback_wwn_, version);
1715
1716 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1717 &scsiback_wwn_attr_version,
1718 NULL,
1719 };
1720
1721 static int scsiback_port_link(struct se_portal_group *se_tpg,
1722 struct se_lun *lun)
1723 {
1724 struct scsiback_tpg *tpg = container_of(se_tpg,
1725 struct scsiback_tpg, se_tpg);
1726
1727 mutex_lock(&tpg->tv_tpg_mutex);
1728 tpg->tv_tpg_port_count++;
1729 mutex_unlock(&tpg->tv_tpg_mutex);
1730
1731 return 0;
1732 }
1733
1734 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1735 struct se_lun *lun)
1736 {
1737 struct scsiback_tpg *tpg = container_of(se_tpg,
1738 struct scsiback_tpg, se_tpg);
1739
1740 mutex_lock(&tpg->tv_tpg_mutex);
1741 tpg->tv_tpg_port_count--;
1742 mutex_unlock(&tpg->tv_tpg_mutex);
1743 }
1744
1745 static struct se_portal_group *
1746 scsiback_make_tpg(struct se_wwn *wwn, const char *name)
1747 {
1748 struct scsiback_tport *tport = container_of(wwn,
1749 struct scsiback_tport, tport_wwn);
1750
1751 struct scsiback_tpg *tpg;
1752 u16 tpgt;
1753 int ret;
1754
1755 if (strstr(name, "tpgt_") != name)
1756 return ERR_PTR(-EINVAL);
1757 ret = kstrtou16(name + 5, 10, &tpgt);
1758 if (ret)
1759 return ERR_PTR(ret);
1760
1761 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1762 if (!tpg)
1763 return ERR_PTR(-ENOMEM);
1764
1765 mutex_init(&tpg->tv_tpg_mutex);
1766 INIT_LIST_HEAD(&tpg->tv_tpg_list);
1767 INIT_LIST_HEAD(&tpg->info_list);
1768 tpg->tport = tport;
1769 tpg->tport_tpgt = tpgt;
1770
1771 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
1772 if (ret < 0) {
1773 kfree(tpg);
1774 return NULL;
1775 }
1776 mutex_lock(&scsiback_mutex);
1777 list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1778 mutex_unlock(&scsiback_mutex);
1779
1780 return &tpg->se_tpg;
1781 }
1782
1783 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1784 {
1785 struct scsiback_tpg *tpg = container_of(se_tpg,
1786 struct scsiback_tpg, se_tpg);
1787
1788 mutex_lock(&scsiback_mutex);
1789 list_del(&tpg->tv_tpg_list);
1790 mutex_unlock(&scsiback_mutex);
1791 /*
1792 * Release the virtual I_T Nexus for this xen-pvscsi TPG
1793 */
1794 scsiback_drop_nexus(tpg);
1795 /*
1796 * Deregister the se_tpg from TCM.
1797 */
1798 core_tpg_deregister(se_tpg);
1799 kfree(tpg);
1800 }
1801
1802 static int scsiback_check_true(struct se_portal_group *se_tpg)
1803 {
1804 return 1;
1805 }
1806
1807 static const struct target_core_fabric_ops scsiback_ops = {
1808 .module = THIS_MODULE,
1809 .fabric_name = "xen-pvscsi",
1810 .tpg_get_wwn = scsiback_get_fabric_wwn,
1811 .tpg_get_tag = scsiback_get_tag,
1812 .tpg_check_demo_mode = scsiback_check_true,
1813 .tpg_check_demo_mode_cache = scsiback_check_true,
1814 .check_stop_free = scsiback_check_stop_free,
1815 .release_cmd = scsiback_release_cmd,
1816 .sess_get_initiator_sid = NULL,
1817 .write_pending = scsiback_write_pending,
1818 .queue_data_in = scsiback_queue_data_in,
1819 .queue_status = scsiback_queue_status,
1820 .queue_tm_rsp = scsiback_queue_tm_rsp,
1821 .aborted_task = scsiback_aborted_task,
1822 /*
1823 * Setup callers for generic logic in target_core_fabric_configfs.c
1824 */
1825 .fabric_make_wwn = scsiback_make_tport,
1826 .fabric_drop_wwn = scsiback_drop_tport,
1827 .fabric_make_tpg = scsiback_make_tpg,
1828 .fabric_drop_tpg = scsiback_drop_tpg,
1829 .fabric_post_link = scsiback_port_link,
1830 .fabric_pre_unlink = scsiback_port_unlink,
1831
1832 .tfc_wwn_attrs = scsiback_wwn_attrs,
1833 .tfc_tpg_base_attrs = scsiback_tpg_attrs,
1834 .tfc_tpg_param_attrs = scsiback_param_attrs,
1835
1836 .default_submit_type = TARGET_DIRECT_SUBMIT,
1837 .direct_submit_supp = 1,
1838 };
1839
1840 static const struct xenbus_device_id scsiback_ids[] = {
1841 { "vscsi" },
1842 { "" }
1843 };
1844
1845 static struct xenbus_driver scsiback_driver = {
1846 .ids = scsiback_ids,
1847 .probe = scsiback_probe,
1848 .remove = scsiback_remove,
1849 .otherend_changed = scsiback_frontend_changed
1850 };
1851
1852 static int __init scsiback_init(void)
1853 {
1854 int ret;
1855
1856 if (!xen_domain())
1857 return -ENODEV;
1858
1859 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
1860 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1861
1862 ret = xenbus_register_backend(&scsiback_driver);
1863 if (ret)
1864 goto out;
1865
1866 ret = target_register_template(&scsiback_ops);
1867 if (ret)
1868 goto out_unregister_xenbus;
1869
1870 return 0;
1871
1872 out_unregister_xenbus:
1873 xenbus_unregister_driver(&scsiback_driver);
1874 out:
1875 pr_err("%s: error %d\n", __func__, ret);
1876 return ret;
1877 }
1878
1879 static void __exit scsiback_exit(void)
1880 {
1881 target_unregister_template(&scsiback_ops);
1882 xenbus_unregister_driver(&scsiback_driver);
1883 }
1884
1885 module_init(scsiback_init);
1886 module_exit(scsiback_exit);
1887
1888 MODULE_DESCRIPTION("Xen SCSI backend driver");
1889 MODULE_LICENSE("Dual BSD/GPL");
1890 MODULE_ALIAS("xen-backend:vscsi");
1891 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
Kernel DRM miscellaneous fixes and cross-tree changes