Merge tag 'asm-generic-mmu-context-5.11' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-microblaze.git] / drivers / xen / xen-scsiback.c
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
95         spinlock_t ring_lock;
96         atomic_t nr_unreplied_reqs;
97
98         spinlock_t v2p_lock;
99         struct list_head v2p_entry_lists;
100
101         wait_queue_head_t waiting_to_free;
102
103         struct gnttab_page_cache free_pages;
104 };
105
106 /* theoretical maximum of grants for one request */
107 #define VSCSI_MAX_GRANTS        (SG_ALL + VSCSIIF_SG_TABLESIZE)
108
109 /*
110  * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
111  * call to map/unmap grants. Don't choose it too large, as there are arrays
112  * with VSCSI_GRANT_BATCH elements allocated on the stack.
113  */
114 #define VSCSI_GRANT_BATCH       16
115
116 struct vscsibk_pend {
117         uint16_t rqid;
118
119         uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
120         uint8_t cmd_len;
121
122         uint8_t sc_data_direction;
123         uint16_t n_sg;          /* real length of SG list */
124         uint16_t n_grants;      /* SG pages and potentially SG list */
125         uint32_t data_len;
126         uint32_t result;
127
128         struct vscsibk_info *info;
129         struct v2p_entry *v2p;
130         struct scatterlist *sgl;
131
132         uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
133
134         grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
135         struct page *pages[VSCSI_MAX_GRANTS];
136
137         struct se_cmd se_cmd;
138
139         struct completion tmr_done;
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 /* Global spinlock to protect scsiback TPG list */
194 static DEFINE_MUTEX(scsiback_mutex);
195 static LIST_HEAD(scsiback_list);
196
197 static void scsiback_get(struct vscsibk_info *info)
198 {
199         atomic_inc(&info->nr_unreplied_reqs);
200 }
201
202 static void scsiback_put(struct vscsibk_info *info)
203 {
204         if (atomic_dec_and_test(&info->nr_unreplied_reqs))
205                 wake_up(&info->waiting_to_free);
206 }
207
208 static unsigned long vaddr_page(struct page *page)
209 {
210         unsigned long pfn = page_to_pfn(page);
211
212         return (unsigned long)pfn_to_kaddr(pfn);
213 }
214
215 static unsigned long vaddr(struct vscsibk_pend *req, int seg)
216 {
217         return vaddr_page(req->pages[seg]);
218 }
219
220 static void scsiback_print_status(char *sense_buffer, int errors,
221                                         struct vscsibk_pend *pending_req)
222 {
223         struct scsiback_tpg *tpg = pending_req->v2p->tpg;
224
225         pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n",
226                tpg->tport->tport_name, pending_req->v2p->lun,
227                pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
228                host_byte(errors), driver_byte(errors));
229 }
230
231 static void scsiback_fast_flush_area(struct vscsibk_pend *req)
232 {
233         struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
234         struct page *pages[VSCSI_GRANT_BATCH];
235         unsigned int i, invcount = 0;
236         grant_handle_t handle;
237         int err;
238
239         kfree(req->sgl);
240         req->sgl = NULL;
241         req->n_sg = 0;
242
243         if (!req->n_grants)
244                 return;
245
246         for (i = 0; i < req->n_grants; i++) {
247                 handle = req->grant_handles[i];
248                 if (handle == SCSIBACK_INVALID_HANDLE)
249                         continue;
250                 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
251                                     GNTMAP_host_map, handle);
252                 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
253                 pages[invcount] = req->pages[i];
254                 put_page(pages[invcount]);
255                 invcount++;
256                 if (invcount < VSCSI_GRANT_BATCH)
257                         continue;
258                 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
259                 BUG_ON(err);
260                 invcount = 0;
261         }
262
263         if (invcount) {
264                 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
265                 BUG_ON(err);
266         }
267
268         gnttab_page_cache_put(&req->info->free_pages, req->pages,
269                               req->n_grants);
270         req->n_grants = 0;
271 }
272
273 static void scsiback_free_translation_entry(struct kref *kref)
274 {
275         struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
276         struct scsiback_tpg *tpg = entry->tpg;
277
278         mutex_lock(&tpg->tv_tpg_mutex);
279         tpg->tv_tpg_fe_count--;
280         mutex_unlock(&tpg->tv_tpg_mutex);
281
282         kfree(entry);
283 }
284
285 static void scsiback_send_response(struct vscsibk_info *info,
286                         char *sense_buffer, int32_t result, uint32_t resid,
287                         uint16_t rqid)
288 {
289         struct vscsiif_response *ring_res;
290         int notify;
291         struct scsi_sense_hdr sshdr;
292         unsigned long flags;
293         unsigned len;
294
295         spin_lock_irqsave(&info->ring_lock, flags);
296
297         ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
298         info->ring.rsp_prod_pvt++;
299
300         ring_res->rslt   = result;
301         ring_res->rqid   = rqid;
302
303         if (sense_buffer != NULL &&
304             scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
305                                  &sshdr)) {
306                 len = min_t(unsigned, 8 + sense_buffer[7],
307                             VSCSIIF_SENSE_BUFFERSIZE);
308                 memcpy(ring_res->sense_buffer, sense_buffer, len);
309                 ring_res->sense_len = len;
310         } else {
311                 ring_res->sense_len = 0;
312         }
313
314         ring_res->residual_len = resid;
315
316         RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
317         spin_unlock_irqrestore(&info->ring_lock, flags);
318
319         if (notify)
320                 notify_remote_via_irq(info->irq);
321 }
322
323 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
324                         uint32_t resid, struct vscsibk_pend *pending_req)
325 {
326         scsiback_send_response(pending_req->info, sense_buffer, result,
327                                resid, pending_req->rqid);
328
329         if (pending_req->v2p)
330                 kref_put(&pending_req->v2p->kref,
331                          scsiback_free_translation_entry);
332 }
333
334 static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
335 {
336         struct vscsibk_info *info = pending_req->info;
337         unsigned char *sense_buffer;
338         unsigned int resid;
339         int errors;
340
341         sense_buffer = pending_req->sense_buffer;
342         resid        = pending_req->se_cmd.residual_count;
343         errors       = pending_req->result;
344
345         if (errors && log_print_stat)
346                 scsiback_print_status(sense_buffer, errors, pending_req);
347
348         scsiback_fast_flush_area(pending_req);
349         scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
350         scsiback_put(info);
351         /*
352          * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls()
353          * ahead of scsiback_check_stop_free() ->  transport_generic_free_cmd()
354          * final se_cmd->cmd_kref put.
355          */
356         target_put_sess_cmd(&pending_req->se_cmd);
357 }
358
359 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
360 {
361         struct se_cmd *se_cmd = &pending_req->se_cmd;
362         struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
363         int rc;
364
365         scsiback_get(pending_req->info);
366         se_cmd->tag = pending_req->rqid;
367         rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
368                         pending_req->sense_buffer, pending_req->v2p->lun,
369                         pending_req->data_len, 0,
370                         pending_req->sc_data_direction, TARGET_SCF_ACK_KREF,
371                         pending_req->sgl, pending_req->n_sg,
372                         NULL, 0, NULL, 0);
373         if (rc < 0) {
374                 transport_send_check_condition_and_sense(se_cmd,
375                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
376                 transport_generic_free_cmd(se_cmd, 0);
377         }
378 }
379
380 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
381         struct page **pg, grant_handle_t *grant, int cnt)
382 {
383         int err, i;
384
385         if (!cnt)
386                 return 0;
387
388         err = gnttab_map_refs(map, NULL, pg, cnt);
389         BUG_ON(err);
390         for (i = 0; i < cnt; i++) {
391                 if (unlikely(map[i].status != GNTST_okay)) {
392                         pr_err("invalid buffer -- could not remap it\n");
393                         map[i].handle = SCSIBACK_INVALID_HANDLE;
394                         err = -ENOMEM;
395                 } else {
396                         get_page(pg[i]);
397                 }
398                 grant[i] = map[i].handle;
399         }
400         return err;
401 }
402
403 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
404                         struct scsiif_request_segment *seg, struct page **pg,
405                         grant_handle_t *grant, int cnt, u32 flags)
406 {
407         int mapcount = 0, i, err = 0;
408         struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
409         struct vscsibk_info *info = pending_req->info;
410
411         for (i = 0; i < cnt; i++) {
412                 if (gnttab_page_cache_get(&info->free_pages, pg + mapcount)) {
413                         gnttab_page_cache_put(&info->free_pages, pg, mapcount);
414                         pr_err("no grant page\n");
415                         return -ENOMEM;
416                 }
417                 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
418                                   flags, seg[i].gref, info->domid);
419                 mapcount++;
420                 if (mapcount < VSCSI_GRANT_BATCH)
421                         continue;
422                 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
423                 pg += mapcount;
424                 grant += mapcount;
425                 pending_req->n_grants += mapcount;
426                 if (err)
427                         return err;
428                 mapcount = 0;
429         }
430         err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
431         pending_req->n_grants += mapcount;
432         return err;
433 }
434
435 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
436                                         struct vscsibk_pend *pending_req)
437 {
438         u32 flags;
439         int i, err, n_segs, i_seg = 0;
440         struct page **pg;
441         struct scsiif_request_segment *seg;
442         unsigned long end_seg = 0;
443         unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
444         unsigned int nr_sgl = 0;
445         struct scatterlist *sg;
446         grant_handle_t *grant;
447
448         pending_req->n_sg = 0;
449         pending_req->n_grants = 0;
450         pending_req->data_len = 0;
451
452         nr_segments &= ~VSCSIIF_SG_GRANT;
453         if (!nr_segments)
454                 return 0;
455
456         if (nr_segments > VSCSIIF_SG_TABLESIZE) {
457                 pr_debug("invalid parameter nr_seg = %d\n",
458                         ring_req->nr_segments);
459                 return -EINVAL;
460         }
461
462         if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
463                 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
464                         pending_req->pages, pending_req->grant_handles,
465                         nr_segments, GNTMAP_host_map | GNTMAP_readonly);
466                 if (err)
467                         return err;
468                 nr_sgl = nr_segments;
469                 nr_segments = 0;
470                 for (i = 0; i < nr_sgl; i++) {
471                         n_segs = ring_req->seg[i].length /
472                                  sizeof(struct scsiif_request_segment);
473                         if ((unsigned)ring_req->seg[i].offset +
474                             (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
475                             n_segs * sizeof(struct scsiif_request_segment) !=
476                             ring_req->seg[i].length)
477                                 return -EINVAL;
478                         nr_segments += n_segs;
479                 }
480                 if (nr_segments > SG_ALL) {
481                         pr_debug("invalid nr_seg = %d\n", nr_segments);
482                         return -EINVAL;
483                 }
484         }
485
486         /* free of (sgl) in fast_flush_area() */
487         pending_req->sgl = kmalloc_array(nr_segments,
488                                         sizeof(struct scatterlist), GFP_KERNEL);
489         if (!pending_req->sgl)
490                 return -ENOMEM;
491
492         sg_init_table(pending_req->sgl, nr_segments);
493         pending_req->n_sg = nr_segments;
494
495         flags = GNTMAP_host_map;
496         if (pending_req->sc_data_direction == DMA_TO_DEVICE)
497                 flags |= GNTMAP_readonly;
498
499         pg = pending_req->pages + nr_sgl;
500         grant = pending_req->grant_handles + nr_sgl;
501         if (!nr_sgl) {
502                 seg = ring_req->seg;
503                 err = scsiback_gnttab_data_map_list(pending_req, seg,
504                         pg, grant, nr_segments, flags);
505                 if (err)
506                         return err;
507         } else {
508                 for (i = 0; i < nr_sgl; i++) {
509                         seg = (struct scsiif_request_segment *)(
510                               vaddr(pending_req, i) + ring_req->seg[i].offset);
511                         n_segs = ring_req->seg[i].length /
512                                  sizeof(struct scsiif_request_segment);
513                         err = scsiback_gnttab_data_map_list(pending_req, seg,
514                                 pg, grant, n_segs, flags);
515                         if (err)
516                                 return err;
517                         pg += n_segs;
518                         grant += n_segs;
519                 }
520                 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
521                 seg = (struct scsiif_request_segment *)end_seg;
522                 end_seg += ring_req->seg[0].length;
523                 pg = pending_req->pages + nr_sgl;
524         }
525
526         for_each_sg(pending_req->sgl, sg, nr_segments, i) {
527                 sg_set_page(sg, pg[i], seg->length, seg->offset);
528                 pending_req->data_len += seg->length;
529                 seg++;
530                 if (nr_sgl && (unsigned long)seg >= end_seg) {
531                         i_seg++;
532                         end_seg = vaddr(pending_req, i_seg) +
533                                   ring_req->seg[i_seg].offset;
534                         seg = (struct scsiif_request_segment *)end_seg;
535                         end_seg += ring_req->seg[i_seg].length;
536                 }
537                 if (sg->offset >= PAGE_SIZE ||
538                     sg->length > PAGE_SIZE ||
539                     sg->offset + sg->length > PAGE_SIZE)
540                         return -EINVAL;
541         }
542
543         return 0;
544 }
545
546 static void scsiback_disconnect(struct vscsibk_info *info)
547 {
548         wait_event(info->waiting_to_free,
549                 atomic_read(&info->nr_unreplied_reqs) == 0);
550
551         unbind_from_irqhandler(info->irq, info);
552         info->irq = 0;
553         xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
554 }
555
556 static void scsiback_device_action(struct vscsibk_pend *pending_req,
557         enum tcm_tmreq_table act, int tag)
558 {
559         struct scsiback_tpg *tpg = pending_req->v2p->tpg;
560         struct scsiback_nexus *nexus = tpg->tpg_nexus;
561         struct se_cmd *se_cmd = &pending_req->se_cmd;
562         u64 unpacked_lun = pending_req->v2p->lun;
563         int rc, err = FAILED;
564
565         init_completion(&pending_req->tmr_done);
566
567         rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess,
568                                &pending_req->sense_buffer[0],
569                                unpacked_lun, NULL, act, GFP_KERNEL,
570                                tag, TARGET_SCF_ACK_KREF);
571         if (rc)
572                 goto err;
573
574         wait_for_completion(&pending_req->tmr_done);
575
576         err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
577                 SUCCESS : FAILED;
578
579         scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
580         transport_generic_free_cmd(&pending_req->se_cmd, 0);
581         return;
582
583 err:
584         scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
585 }
586
587 /*
588   Perform virtual to physical translation
589 */
590 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
591                         struct ids_tuple *v)
592 {
593         struct v2p_entry *entry;
594         struct list_head *head = &(info->v2p_entry_lists);
595         unsigned long flags;
596
597         spin_lock_irqsave(&info->v2p_lock, flags);
598         list_for_each_entry(entry, head, l) {
599                 if ((entry->v.chn == v->chn) &&
600                     (entry->v.tgt == v->tgt) &&
601                     (entry->v.lun == v->lun)) {
602                         kref_get(&entry->kref);
603                         goto out;
604                 }
605         }
606         entry = NULL;
607
608 out:
609         spin_unlock_irqrestore(&info->v2p_lock, flags);
610         return entry;
611 }
612
613 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring,
614                                 struct v2p_entry *v2p)
615 {
616         struct scsiback_tpg *tpg = v2p->tpg;
617         struct scsiback_nexus *nexus = tpg->tpg_nexus;
618         struct se_session *se_sess = nexus->tvn_se_sess;
619         struct vscsibk_pend *req;
620         int tag, cpu, i;
621
622         tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
623         if (tag < 0) {
624                 pr_err("Unable to obtain tag for vscsiif_request\n");
625                 return ERR_PTR(-ENOMEM);
626         }
627
628         req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
629         memset(req, 0, sizeof(*req));
630         req->se_cmd.map_tag = tag;
631         req->se_cmd.map_cpu = cpu;
632
633         for (i = 0; i < VSCSI_MAX_GRANTS; i++)
634                 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
635
636         return req;
637 }
638
639 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
640                                 struct vscsiif_back_ring *ring,
641                                 struct vscsiif_request *ring_req)
642 {
643         struct vscsibk_pend *pending_req;
644         struct v2p_entry *v2p;
645         struct ids_tuple vir;
646
647         /* request range check from frontend */
648         if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
649                 (ring_req->sc_data_direction != DMA_TO_DEVICE) &&
650                 (ring_req->sc_data_direction != DMA_FROM_DEVICE) &&
651                 (ring_req->sc_data_direction != DMA_NONE)) {
652                 pr_debug("invalid parameter data_dir = %d\n",
653                         ring_req->sc_data_direction);
654                 return ERR_PTR(-EINVAL);
655         }
656         if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
657                 pr_debug("invalid parameter cmd_len = %d\n",
658                         ring_req->cmd_len);
659                 return ERR_PTR(-EINVAL);
660         }
661
662         vir.chn = ring_req->channel;
663         vir.tgt = ring_req->id;
664         vir.lun = ring_req->lun;
665
666         v2p = scsiback_do_translation(info, &vir);
667         if (!v2p) {
668                 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
669                          vir.chn, vir.tgt, vir.lun);
670                 return ERR_PTR(-ENODEV);
671         }
672
673         pending_req = scsiback_get_pend_req(ring, v2p);
674         if (IS_ERR(pending_req)) {
675                 kref_put(&v2p->kref, scsiback_free_translation_entry);
676                 return ERR_PTR(-ENOMEM);
677         }
678         pending_req->rqid = ring_req->rqid;
679         pending_req->info = info;
680         pending_req->v2p = v2p;
681         pending_req->sc_data_direction = ring_req->sc_data_direction;
682         pending_req->cmd_len = ring_req->cmd_len;
683         memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
684
685         return pending_req;
686 }
687
688 static int scsiback_do_cmd_fn(struct vscsibk_info *info,
689                               unsigned int *eoi_flags)
690 {
691         struct vscsiif_back_ring *ring = &info->ring;
692         struct vscsiif_request ring_req;
693         struct vscsibk_pend *pending_req;
694         RING_IDX rc, rp;
695         int more_to_do;
696         uint32_t result;
697
698         rc = ring->req_cons;
699         rp = ring->sring->req_prod;
700         rmb();  /* guest system is accessing ring, too */
701
702         if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
703                 rc = ring->rsp_prod_pvt;
704                 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
705                            info->domid, rp, rc, rp - rc);
706                 return -EINVAL;
707         }
708
709         while ((rc != rp)) {
710                 *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
711
712                 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
713                         break;
714
715                 RING_COPY_REQUEST(ring, rc, &ring_req);
716                 ring->req_cons = ++rc;
717
718                 pending_req = prepare_pending_reqs(info, ring, &ring_req);
719                 if (IS_ERR(pending_req)) {
720                         switch (PTR_ERR(pending_req)) {
721                         case -ENODEV:
722                                 result = DID_NO_CONNECT;
723                                 break;
724                         default:
725                                 result = DRIVER_ERROR;
726                                 break;
727                         }
728                         scsiback_send_response(info, NULL, result << 24, 0,
729                                                ring_req.rqid);
730                         return 1;
731                 }
732
733                 switch (ring_req.act) {
734                 case VSCSIIF_ACT_SCSI_CDB:
735                         if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
736                                 scsiback_fast_flush_area(pending_req);
737                                 scsiback_do_resp_with_sense(NULL,
738                                                 DRIVER_ERROR << 24, 0, pending_req);
739                                 transport_generic_free_cmd(&pending_req->se_cmd, 0);
740                         } else {
741                                 scsiback_cmd_exec(pending_req);
742                         }
743                         break;
744                 case VSCSIIF_ACT_SCSI_ABORT:
745                         scsiback_device_action(pending_req, TMR_ABORT_TASK,
746                                 ring_req.ref_rqid);
747                         break;
748                 case VSCSIIF_ACT_SCSI_RESET:
749                         scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
750                         break;
751                 default:
752                         pr_err_ratelimited("invalid request\n");
753                         scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24, 0,
754                                                     pending_req);
755                         transport_generic_free_cmd(&pending_req->se_cmd, 0);
756                         break;
757                 }
758
759                 /* Yield point for this unbounded loop. */
760                 cond_resched();
761         }
762
763         gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages);
764
765         RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
766         return more_to_do;
767 }
768
769 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
770 {
771         struct vscsibk_info *info = dev_id;
772         int rc;
773         unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
774
775         while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0)
776                 cond_resched();
777
778         /* In case of a ring error we keep the event channel masked. */
779         if (!rc)
780                 xen_irq_lateeoi(irq, eoi_flags);
781
782         return IRQ_HANDLED;
783 }
784
785 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
786                         evtchn_port_t evtchn)
787 {
788         void *area;
789         struct vscsiif_sring *sring;
790         int err;
791
792         if (info->irq)
793                 return -1;
794
795         err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
796         if (err)
797                 return err;
798
799         sring = (struct vscsiif_sring *)area;
800         BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
801
802         err = bind_interdomain_evtchn_to_irq_lateeoi(info->domid, evtchn);
803         if (err < 0)
804                 goto unmap_page;
805
806         info->irq = err;
807
808         err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
809                                    IRQF_ONESHOT, "vscsiif-backend", info);
810         if (err)
811                 goto free_irq;
812
813         return 0;
814
815 free_irq:
816         unbind_from_irqhandler(info->irq, info);
817         info->irq = 0;
818 unmap_page:
819         xenbus_unmap_ring_vfree(info->dev, area);
820
821         return err;
822 }
823
824 static int scsiback_map(struct vscsibk_info *info)
825 {
826         struct xenbus_device *dev = info->dev;
827         unsigned int ring_ref;
828         evtchn_port_t evtchn;
829         int err;
830
831         err = xenbus_gather(XBT_NIL, dev->otherend,
832                         "ring-ref", "%u", &ring_ref,
833                         "event-channel", "%u", &evtchn, NULL);
834         if (err) {
835                 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
836                 return err;
837         }
838
839         return scsiback_init_sring(info, ring_ref, evtchn);
840 }
841
842 /*
843   Check for a translation entry being present
844 */
845 static struct v2p_entry *scsiback_chk_translation_entry(
846         struct vscsibk_info *info, struct ids_tuple *v)
847 {
848         struct list_head *head = &(info->v2p_entry_lists);
849         struct v2p_entry *entry;
850
851         list_for_each_entry(entry, head, l)
852                 if ((entry->v.chn == v->chn) &&
853                     (entry->v.tgt == v->tgt) &&
854                     (entry->v.lun == v->lun))
855                         return entry;
856
857         return NULL;
858 }
859
860 /*
861   Add a new translation entry
862 */
863 static int scsiback_add_translation_entry(struct vscsibk_info *info,
864                                           char *phy, struct ids_tuple *v)
865 {
866         int err = 0;
867         struct v2p_entry *new;
868         unsigned long flags;
869         char *lunp;
870         unsigned long long unpacked_lun;
871         struct se_lun *se_lun;
872         struct scsiback_tpg *tpg_entry, *tpg = NULL;
873         char *error = "doesn't exist";
874
875         lunp = strrchr(phy, ':');
876         if (!lunp) {
877                 pr_err("illegal format of physical device %s\n", phy);
878                 return -EINVAL;
879         }
880         *lunp = 0;
881         lunp++;
882         err = kstrtoull(lunp, 10, &unpacked_lun);
883         if (err < 0) {
884                 pr_err("lun number not valid: %s\n", lunp);
885                 return err;
886         }
887
888         mutex_lock(&scsiback_mutex);
889         list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
890                 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
891                     !strcmp(phy, tpg_entry->param_alias)) {
892                         mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex);
893                         hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) {
894                                 if (se_lun->unpacked_lun == unpacked_lun) {
895                                         if (!tpg_entry->tpg_nexus)
896                                                 error = "nexus undefined";
897                                         else
898                                                 tpg = tpg_entry;
899                                         break;
900                                 }
901                         }
902                         mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex);
903                         break;
904                 }
905         }
906         if (tpg) {
907                 mutex_lock(&tpg->tv_tpg_mutex);
908                 tpg->tv_tpg_fe_count++;
909                 mutex_unlock(&tpg->tv_tpg_mutex);
910         }
911         mutex_unlock(&scsiback_mutex);
912
913         if (!tpg) {
914                 pr_err("%s:%llu %s\n", phy, unpacked_lun, error);
915                 return -ENODEV;
916         }
917
918         new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
919         if (new == NULL) {
920                 err = -ENOMEM;
921                 goto out_free;
922         }
923
924         spin_lock_irqsave(&info->v2p_lock, flags);
925
926         /* Check double assignment to identical virtual ID */
927         if (scsiback_chk_translation_entry(info, v)) {
928                 pr_warn("Virtual ID is already used. Assignment was not performed.\n");
929                 err = -EEXIST;
930                 goto out;
931         }
932
933         /* Create a new translation entry and add to the list */
934         kref_init(&new->kref);
935         new->v = *v;
936         new->tpg = tpg;
937         new->lun = unpacked_lun;
938         list_add_tail(&new->l, &info->v2p_entry_lists);
939
940 out:
941         spin_unlock_irqrestore(&info->v2p_lock, flags);
942
943 out_free:
944         if (err) {
945                 mutex_lock(&tpg->tv_tpg_mutex);
946                 tpg->tv_tpg_fe_count--;
947                 mutex_unlock(&tpg->tv_tpg_mutex);
948                 kfree(new);
949         }
950
951         return err;
952 }
953
954 static void __scsiback_del_translation_entry(struct v2p_entry *entry)
955 {
956         list_del(&entry->l);
957         kref_put(&entry->kref, scsiback_free_translation_entry);
958 }
959
960 /*
961   Delete the translation entry specified
962 */
963 static int scsiback_del_translation_entry(struct vscsibk_info *info,
964                                           struct ids_tuple *v)
965 {
966         struct v2p_entry *entry;
967         unsigned long flags;
968         int ret = 0;
969
970         spin_lock_irqsave(&info->v2p_lock, flags);
971         /* Find out the translation entry specified */
972         entry = scsiback_chk_translation_entry(info, v);
973         if (entry)
974                 __scsiback_del_translation_entry(entry);
975         else
976                 ret = -ENOENT;
977
978         spin_unlock_irqrestore(&info->v2p_lock, flags);
979         return ret;
980 }
981
982 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
983                                 char *phy, struct ids_tuple *vir, int try)
984 {
985         struct v2p_entry *entry;
986         unsigned long flags;
987         int err;
988
989         if (try) {
990                 spin_lock_irqsave(&info->v2p_lock, flags);
991                 entry = scsiback_chk_translation_entry(info, vir);
992                 spin_unlock_irqrestore(&info->v2p_lock, flags);
993                 if (entry)
994                         return;
995         }
996         if (!scsiback_add_translation_entry(info, phy, vir)) {
997                 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
998                                   "%d", XenbusStateInitialised)) {
999                         pr_err("xenbus_printf error %s\n", state);
1000                         scsiback_del_translation_entry(info, vir);
1001                 }
1002         } else if (!try) {
1003                 err = xenbus_printf(XBT_NIL, info->dev->nodename, state,
1004                               "%d", XenbusStateClosed);
1005                 if (err)
1006                         xenbus_dev_error(info->dev, err,
1007                                 "%s: writing %s", __func__, state);
1008         }
1009 }
1010
1011 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1012                                 struct ids_tuple *vir)
1013 {
1014         if (!scsiback_del_translation_entry(info, vir)) {
1015                 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1016                                   "%d", XenbusStateClosed))
1017                         pr_err("xenbus_printf error %s\n", state);
1018         }
1019 }
1020
1021 #define VSCSIBACK_OP_ADD_OR_DEL_LUN     1
1022 #define VSCSIBACK_OP_UPDATEDEV_STATE    2
1023
1024 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1025                                      char *ent)
1026 {
1027         int err;
1028         struct ids_tuple vir;
1029         char *val;
1030         int device_state;
1031         char phy[VSCSI_NAMELEN];
1032         char str[64];
1033         char state[64];
1034         struct xenbus_device *dev = info->dev;
1035
1036         /* read status */
1037         snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1038         err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1039         if (XENBUS_EXIST_ERR(err))
1040                 return;
1041
1042         /* physical SCSI device */
1043         snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1044         val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1045         if (IS_ERR(val)) {
1046                 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1047                               "%d", XenbusStateClosed);
1048                 if (err)
1049                         xenbus_dev_error(info->dev, err,
1050                                 "%s: writing %s", __func__, state);
1051                 return;
1052         }
1053         strlcpy(phy, val, VSCSI_NAMELEN);
1054         kfree(val);
1055
1056         /* virtual SCSI device */
1057         snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1058         err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1059                            &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1060         if (XENBUS_EXIST_ERR(err)) {
1061                 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1062                               "%d", XenbusStateClosed);
1063                 if (err)
1064                         xenbus_dev_error(info->dev, err,
1065                                 "%s: writing %s", __func__, state);
1066                 return;
1067         }
1068
1069         switch (op) {
1070         case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1071                 switch (device_state) {
1072                 case XenbusStateInitialising:
1073                         scsiback_do_add_lun(info, state, phy, &vir, 0);
1074                         break;
1075                 case XenbusStateConnected:
1076                         scsiback_do_add_lun(info, state, phy, &vir, 1);
1077                         break;
1078                 case XenbusStateClosing:
1079                         scsiback_do_del_lun(info, state, &vir);
1080                         break;
1081                 default:
1082                         break;
1083                 }
1084                 break;
1085
1086         case VSCSIBACK_OP_UPDATEDEV_STATE:
1087                 if (device_state == XenbusStateInitialised) {
1088                         /* modify vscsi-devs/dev-x/state */
1089                         if (xenbus_printf(XBT_NIL, dev->nodename, state,
1090                                           "%d", XenbusStateConnected)) {
1091                                 pr_err("xenbus_printf error %s\n", str);
1092                                 scsiback_del_translation_entry(info, &vir);
1093                                 xenbus_printf(XBT_NIL, dev->nodename, state,
1094                                               "%d", XenbusStateClosed);
1095                         }
1096                 }
1097                 break;
1098         /* When it is necessary, processing is added here. */
1099         default:
1100                 break;
1101         }
1102 }
1103
1104 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1105 {
1106         int i;
1107         char **dir;
1108         unsigned int ndir = 0;
1109
1110         dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1111                                &ndir);
1112         if (IS_ERR(dir))
1113                 return;
1114
1115         for (i = 0; i < ndir; i++)
1116                 scsiback_do_1lun_hotplug(info, op, dir[i]);
1117
1118         kfree(dir);
1119 }
1120
1121 static void scsiback_frontend_changed(struct xenbus_device *dev,
1122                                         enum xenbus_state frontend_state)
1123 {
1124         struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1125
1126         switch (frontend_state) {
1127         case XenbusStateInitialising:
1128                 break;
1129
1130         case XenbusStateInitialised:
1131                 if (scsiback_map(info))
1132                         break;
1133
1134                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1135                 xenbus_switch_state(dev, XenbusStateConnected);
1136                 break;
1137
1138         case XenbusStateConnected:
1139                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1140
1141                 if (dev->state == XenbusStateConnected)
1142                         break;
1143
1144                 xenbus_switch_state(dev, XenbusStateConnected);
1145                 break;
1146
1147         case XenbusStateClosing:
1148                 if (info->irq)
1149                         scsiback_disconnect(info);
1150
1151                 xenbus_switch_state(dev, XenbusStateClosing);
1152                 break;
1153
1154         case XenbusStateClosed:
1155                 xenbus_switch_state(dev, XenbusStateClosed);
1156                 if (xenbus_dev_is_online(dev))
1157                         break;
1158                 fallthrough;    /* if not online */
1159         case XenbusStateUnknown:
1160                 device_unregister(&dev->dev);
1161                 break;
1162
1163         case XenbusStateReconfiguring:
1164                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1165                 xenbus_switch_state(dev, XenbusStateReconfigured);
1166
1167                 break;
1168
1169         default:
1170                 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1171                                         frontend_state);
1172                 break;
1173         }
1174 }
1175
1176 /*
1177   Release the translation entry specfied
1178 */
1179 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1180 {
1181         struct v2p_entry *entry, *tmp;
1182         struct list_head *head = &(info->v2p_entry_lists);
1183         unsigned long flags;
1184
1185         spin_lock_irqsave(&info->v2p_lock, flags);
1186
1187         list_for_each_entry_safe(entry, tmp, head, l)
1188                 __scsiback_del_translation_entry(entry);
1189
1190         spin_unlock_irqrestore(&info->v2p_lock, flags);
1191 }
1192
1193 static int scsiback_remove(struct xenbus_device *dev)
1194 {
1195         struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1196
1197         if (info->irq)
1198                 scsiback_disconnect(info);
1199
1200         scsiback_release_translation_entry(info);
1201
1202         gnttab_page_cache_shrink(&info->free_pages, 0);
1203
1204         dev_set_drvdata(&dev->dev, NULL);
1205
1206         return 0;
1207 }
1208
1209 static int scsiback_probe(struct xenbus_device *dev,
1210                            const struct xenbus_device_id *id)
1211 {
1212         int err;
1213
1214         struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1215                                             GFP_KERNEL);
1216
1217         pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
1218
1219         if (!info) {
1220                 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1221                 return -ENOMEM;
1222         }
1223         info->dev = dev;
1224         dev_set_drvdata(&dev->dev, info);
1225
1226         info->domid = dev->otherend_id;
1227         spin_lock_init(&info->ring_lock);
1228         atomic_set(&info->nr_unreplied_reqs, 0);
1229         init_waitqueue_head(&info->waiting_to_free);
1230         info->dev = dev;
1231         info->irq = 0;
1232         INIT_LIST_HEAD(&info->v2p_entry_lists);
1233         spin_lock_init(&info->v2p_lock);
1234         gnttab_page_cache_init(&info->free_pages);
1235
1236         err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1237                             SG_ALL);
1238         if (err)
1239                 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1240
1241         err = xenbus_switch_state(dev, XenbusStateInitWait);
1242         if (err)
1243                 goto fail;
1244
1245         return 0;
1246
1247 fail:
1248         pr_warn("%s failed\n", __func__);
1249         scsiback_remove(dev);
1250
1251         return err;
1252 }
1253
1254 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1255 {
1256         switch (tport->tport_proto_id) {
1257         case SCSI_PROTOCOL_SAS:
1258                 return "SAS";
1259         case SCSI_PROTOCOL_FCP:
1260                 return "FCP";
1261         case SCSI_PROTOCOL_ISCSI:
1262                 return "iSCSI";
1263         default:
1264                 break;
1265         }
1266
1267         return "Unknown";
1268 }
1269
1270 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1271 {
1272         struct scsiback_tpg *tpg = container_of(se_tpg,
1273                                 struct scsiback_tpg, se_tpg);
1274         struct scsiback_tport *tport = tpg->tport;
1275
1276         return &tport->tport_name[0];
1277 }
1278
1279 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1280 {
1281         struct scsiback_tpg *tpg = container_of(se_tpg,
1282                                 struct scsiback_tpg, se_tpg);
1283         return tpg->tport_tpgt;
1284 }
1285
1286 static struct se_wwn *
1287 scsiback_make_tport(struct target_fabric_configfs *tf,
1288                      struct config_group *group,
1289                      const char *name)
1290 {
1291         struct scsiback_tport *tport;
1292         char *ptr;
1293         u64 wwpn = 0;
1294         int off = 0;
1295
1296         tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1297         if (!tport)
1298                 return ERR_PTR(-ENOMEM);
1299
1300         tport->tport_wwpn = wwpn;
1301         /*
1302          * Determine the emulated Protocol Identifier and Target Port Name
1303          * based on the incoming configfs directory name.
1304          */
1305         ptr = strstr(name, "naa.");
1306         if (ptr) {
1307                 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1308                 goto check_len;
1309         }
1310         ptr = strstr(name, "fc.");
1311         if (ptr) {
1312                 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1313                 off = 3; /* Skip over "fc." */
1314                 goto check_len;
1315         }
1316         ptr = strstr(name, "iqn.");
1317         if (ptr) {
1318                 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1319                 goto check_len;
1320         }
1321
1322         pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1323         kfree(tport);
1324         return ERR_PTR(-EINVAL);
1325
1326 check_len:
1327         if (strlen(name) >= VSCSI_NAMELEN) {
1328                 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1329                         scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1330                 kfree(tport);
1331                 return ERR_PTR(-EINVAL);
1332         }
1333         snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1334
1335         pr_debug("Allocated emulated Target %s Address: %s\n",
1336                  scsiback_dump_proto_id(tport), name);
1337
1338         return &tport->tport_wwn;
1339 }
1340
1341 static void scsiback_drop_tport(struct se_wwn *wwn)
1342 {
1343         struct scsiback_tport *tport = container_of(wwn,
1344                                 struct scsiback_tport, tport_wwn);
1345
1346         pr_debug("Deallocating emulated Target %s Address: %s\n",
1347                  scsiback_dump_proto_id(tport), tport->tport_name);
1348
1349         kfree(tport);
1350 }
1351
1352 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1353 {
1354         return 1;
1355 }
1356
1357 static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1358 {
1359         return transport_generic_free_cmd(se_cmd, 0);
1360 }
1361
1362 static void scsiback_release_cmd(struct se_cmd *se_cmd)
1363 {
1364         target_free_tag(se_cmd->se_sess, se_cmd);
1365 }
1366
1367 static u32 scsiback_sess_get_index(struct se_session *se_sess)
1368 {
1369         return 0;
1370 }
1371
1372 static int scsiback_write_pending(struct se_cmd *se_cmd)
1373 {
1374         /* Go ahead and process the write immediately */
1375         target_execute_cmd(se_cmd);
1376
1377         return 0;
1378 }
1379
1380 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1381 {
1382 }
1383
1384 static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1385 {
1386         return 0;
1387 }
1388
1389 static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1390 {
1391         struct vscsibk_pend *pending_req = container_of(se_cmd,
1392                                 struct vscsibk_pend, se_cmd);
1393
1394         pending_req->result = SAM_STAT_GOOD;
1395         scsiback_cmd_done(pending_req);
1396         return 0;
1397 }
1398
1399 static int scsiback_queue_status(struct se_cmd *se_cmd)
1400 {
1401         struct vscsibk_pend *pending_req = container_of(se_cmd,
1402                                 struct vscsibk_pend, se_cmd);
1403
1404         if (se_cmd->sense_buffer &&
1405             ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1406              (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1407                 pending_req->result = (DRIVER_SENSE << 24) |
1408                                       SAM_STAT_CHECK_CONDITION;
1409         else
1410                 pending_req->result = se_cmd->scsi_status;
1411
1412         scsiback_cmd_done(pending_req);
1413         return 0;
1414 }
1415
1416 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1417 {
1418         struct vscsibk_pend *pending_req = container_of(se_cmd,
1419                                 struct vscsibk_pend, se_cmd);
1420
1421         complete(&pending_req->tmr_done);
1422 }
1423
1424 static void scsiback_aborted_task(struct se_cmd *se_cmd)
1425 {
1426 }
1427
1428 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item,
1429                                              char *page)
1430 {
1431         struct se_portal_group *se_tpg = param_to_tpg(item);
1432         struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1433                                                 se_tpg);
1434         ssize_t rb;
1435
1436         mutex_lock(&tpg->tv_tpg_mutex);
1437         rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1438         mutex_unlock(&tpg->tv_tpg_mutex);
1439
1440         return rb;
1441 }
1442
1443 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item,
1444                                               const char *page, size_t count)
1445 {
1446         struct se_portal_group *se_tpg = param_to_tpg(item);
1447         struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1448                                                 se_tpg);
1449         int len;
1450
1451         if (strlen(page) >= VSCSI_NAMELEN) {
1452                 pr_err("param alias: %s, exceeds max: %d\n", page,
1453                         VSCSI_NAMELEN);
1454                 return -EINVAL;
1455         }
1456
1457         mutex_lock(&tpg->tv_tpg_mutex);
1458         len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1459         if (tpg->param_alias[len - 1] == '\n')
1460                 tpg->param_alias[len - 1] = '\0';
1461         mutex_unlock(&tpg->tv_tpg_mutex);
1462
1463         return count;
1464 }
1465
1466 CONFIGFS_ATTR(scsiback_tpg_param_, alias);
1467
1468 static struct configfs_attribute *scsiback_param_attrs[] = {
1469         &scsiback_tpg_param_attr_alias,
1470         NULL,
1471 };
1472
1473 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg,
1474                                   struct se_session *se_sess, void *p)
1475 {
1476         struct scsiback_tpg *tpg = container_of(se_tpg,
1477                                 struct scsiback_tpg, se_tpg);
1478
1479         tpg->tpg_nexus = p;
1480         return 0;
1481 }
1482
1483 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1484                                 const char *name)
1485 {
1486         struct scsiback_nexus *tv_nexus;
1487         int ret = 0;
1488
1489         mutex_lock(&tpg->tv_tpg_mutex);
1490         if (tpg->tpg_nexus) {
1491                 pr_debug("tpg->tpg_nexus already exists\n");
1492                 ret = -EEXIST;
1493                 goto out_unlock;
1494         }
1495
1496         tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1497         if (!tv_nexus) {
1498                 ret = -ENOMEM;
1499                 goto out_unlock;
1500         }
1501
1502         tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
1503                                                      VSCSI_DEFAULT_SESSION_TAGS,
1504                                                      sizeof(struct vscsibk_pend),
1505                                                      TARGET_PROT_NORMAL, name,
1506                                                      tv_nexus, scsiback_alloc_sess_cb);
1507         if (IS_ERR(tv_nexus->tvn_se_sess)) {
1508                 kfree(tv_nexus);
1509                 ret = -ENOMEM;
1510                 goto out_unlock;
1511         }
1512
1513 out_unlock:
1514         mutex_unlock(&tpg->tv_tpg_mutex);
1515         return ret;
1516 }
1517
1518 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1519 {
1520         struct se_session *se_sess;
1521         struct scsiback_nexus *tv_nexus;
1522
1523         mutex_lock(&tpg->tv_tpg_mutex);
1524         tv_nexus = tpg->tpg_nexus;
1525         if (!tv_nexus) {
1526                 mutex_unlock(&tpg->tv_tpg_mutex);
1527                 return -ENODEV;
1528         }
1529
1530         se_sess = tv_nexus->tvn_se_sess;
1531         if (!se_sess) {
1532                 mutex_unlock(&tpg->tv_tpg_mutex);
1533                 return -ENODEV;
1534         }
1535
1536         if (tpg->tv_tpg_port_count != 0) {
1537                 mutex_unlock(&tpg->tv_tpg_mutex);
1538                 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1539                         tpg->tv_tpg_port_count);
1540                 return -EBUSY;
1541         }
1542
1543         if (tpg->tv_tpg_fe_count != 0) {
1544                 mutex_unlock(&tpg->tv_tpg_mutex);
1545                 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1546                         tpg->tv_tpg_fe_count);
1547                 return -EBUSY;
1548         }
1549
1550         pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1551                 scsiback_dump_proto_id(tpg->tport),
1552                 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1553
1554         /*
1555          * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1556          */
1557         target_remove_session(se_sess);
1558         tpg->tpg_nexus = NULL;
1559         mutex_unlock(&tpg->tv_tpg_mutex);
1560
1561         kfree(tv_nexus);
1562         return 0;
1563 }
1564
1565 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page)
1566 {
1567         struct se_portal_group *se_tpg = to_tpg(item);
1568         struct scsiback_tpg *tpg = container_of(se_tpg,
1569                                 struct scsiback_tpg, se_tpg);
1570         struct scsiback_nexus *tv_nexus;
1571         ssize_t ret;
1572
1573         mutex_lock(&tpg->tv_tpg_mutex);
1574         tv_nexus = tpg->tpg_nexus;
1575         if (!tv_nexus) {
1576                 mutex_unlock(&tpg->tv_tpg_mutex);
1577                 return -ENODEV;
1578         }
1579         ret = snprintf(page, PAGE_SIZE, "%s\n",
1580                         tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1581         mutex_unlock(&tpg->tv_tpg_mutex);
1582
1583         return ret;
1584 }
1585
1586 static ssize_t scsiback_tpg_nexus_store(struct config_item *item,
1587                 const char *page, size_t count)
1588 {
1589         struct se_portal_group *se_tpg = to_tpg(item);
1590         struct scsiback_tpg *tpg = container_of(se_tpg,
1591                                 struct scsiback_tpg, se_tpg);
1592         struct scsiback_tport *tport_wwn = tpg->tport;
1593         unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1594         int ret;
1595         /*
1596          * Shutdown the active I_T nexus if 'NULL' is passed.
1597          */
1598         if (!strncmp(page, "NULL", 4)) {
1599                 ret = scsiback_drop_nexus(tpg);
1600                 return (!ret) ? count : ret;
1601         }
1602         /*
1603          * Otherwise make sure the passed virtual Initiator port WWN matches
1604          * the fabric protocol_id set in scsiback_make_tport(), and call
1605          * scsiback_make_nexus().
1606          */
1607         if (strlen(page) >= VSCSI_NAMELEN) {
1608                 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1609                         page, VSCSI_NAMELEN);
1610                 return -EINVAL;
1611         }
1612         snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1613
1614         ptr = strstr(i_port, "naa.");
1615         if (ptr) {
1616                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1617                         pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1618                                 i_port, scsiback_dump_proto_id(tport_wwn));
1619                         return -EINVAL;
1620                 }
1621                 port_ptr = &i_port[0];
1622                 goto check_newline;
1623         }
1624         ptr = strstr(i_port, "fc.");
1625         if (ptr) {
1626                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1627                         pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1628                                 i_port, scsiback_dump_proto_id(tport_wwn));
1629                         return -EINVAL;
1630                 }
1631                 port_ptr = &i_port[3]; /* Skip over "fc." */
1632                 goto check_newline;
1633         }
1634         ptr = strstr(i_port, "iqn.");
1635         if (ptr) {
1636                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1637                         pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1638                                 i_port, scsiback_dump_proto_id(tport_wwn));
1639                         return -EINVAL;
1640                 }
1641                 port_ptr = &i_port[0];
1642                 goto check_newline;
1643         }
1644         pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1645                 i_port);
1646         return -EINVAL;
1647         /*
1648          * Clear any trailing newline for the NAA WWN
1649          */
1650 check_newline:
1651         if (i_port[strlen(i_port) - 1] == '\n')
1652                 i_port[strlen(i_port) - 1] = '\0';
1653
1654         ret = scsiback_make_nexus(tpg, port_ptr);
1655         if (ret < 0)
1656                 return ret;
1657
1658         return count;
1659 }
1660
1661 CONFIGFS_ATTR(scsiback_tpg_, nexus);
1662
1663 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1664         &scsiback_tpg_attr_nexus,
1665         NULL,
1666 };
1667
1668 static ssize_t
1669 scsiback_wwn_version_show(struct config_item *item, char *page)
1670 {
1671         return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1672                 UTS_RELEASE"\n",
1673                 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1674 }
1675
1676 CONFIGFS_ATTR_RO(scsiback_wwn_, version);
1677
1678 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1679         &scsiback_wwn_attr_version,
1680         NULL,
1681 };
1682
1683 static int scsiback_port_link(struct se_portal_group *se_tpg,
1684                                struct se_lun *lun)
1685 {
1686         struct scsiback_tpg *tpg = container_of(se_tpg,
1687                                 struct scsiback_tpg, se_tpg);
1688
1689         mutex_lock(&tpg->tv_tpg_mutex);
1690         tpg->tv_tpg_port_count++;
1691         mutex_unlock(&tpg->tv_tpg_mutex);
1692
1693         return 0;
1694 }
1695
1696 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1697                                   struct se_lun *lun)
1698 {
1699         struct scsiback_tpg *tpg = container_of(se_tpg,
1700                                 struct scsiback_tpg, se_tpg);
1701
1702         mutex_lock(&tpg->tv_tpg_mutex);
1703         tpg->tv_tpg_port_count--;
1704         mutex_unlock(&tpg->tv_tpg_mutex);
1705 }
1706
1707 static struct se_portal_group *
1708 scsiback_make_tpg(struct se_wwn *wwn, const char *name)
1709 {
1710         struct scsiback_tport *tport = container_of(wwn,
1711                         struct scsiback_tport, tport_wwn);
1712
1713         struct scsiback_tpg *tpg;
1714         u16 tpgt;
1715         int ret;
1716
1717         if (strstr(name, "tpgt_") != name)
1718                 return ERR_PTR(-EINVAL);
1719         ret = kstrtou16(name + 5, 10, &tpgt);
1720         if (ret)
1721                 return ERR_PTR(ret);
1722
1723         tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1724         if (!tpg)
1725                 return ERR_PTR(-ENOMEM);
1726
1727         mutex_init(&tpg->tv_tpg_mutex);
1728         INIT_LIST_HEAD(&tpg->tv_tpg_list);
1729         INIT_LIST_HEAD(&tpg->info_list);
1730         tpg->tport = tport;
1731         tpg->tport_tpgt = tpgt;
1732
1733         ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
1734         if (ret < 0) {
1735                 kfree(tpg);
1736                 return NULL;
1737         }
1738         mutex_lock(&scsiback_mutex);
1739         list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1740         mutex_unlock(&scsiback_mutex);
1741
1742         return &tpg->se_tpg;
1743 }
1744
1745 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1746 {
1747         struct scsiback_tpg *tpg = container_of(se_tpg,
1748                                 struct scsiback_tpg, se_tpg);
1749
1750         mutex_lock(&scsiback_mutex);
1751         list_del(&tpg->tv_tpg_list);
1752         mutex_unlock(&scsiback_mutex);
1753         /*
1754          * Release the virtual I_T Nexus for this xen-pvscsi TPG
1755          */
1756         scsiback_drop_nexus(tpg);
1757         /*
1758          * Deregister the se_tpg from TCM.
1759          */
1760         core_tpg_deregister(se_tpg);
1761         kfree(tpg);
1762 }
1763
1764 static int scsiback_check_true(struct se_portal_group *se_tpg)
1765 {
1766         return 1;
1767 }
1768
1769 static int scsiback_check_false(struct se_portal_group *se_tpg)
1770 {
1771         return 0;
1772 }
1773
1774 static const struct target_core_fabric_ops scsiback_ops = {
1775         .module                         = THIS_MODULE,
1776         .fabric_name                    = "xen-pvscsi",
1777         .tpg_get_wwn                    = scsiback_get_fabric_wwn,
1778         .tpg_get_tag                    = scsiback_get_tag,
1779         .tpg_check_demo_mode            = scsiback_check_true,
1780         .tpg_check_demo_mode_cache      = scsiback_check_true,
1781         .tpg_check_demo_mode_write_protect = scsiback_check_false,
1782         .tpg_check_prod_mode_write_protect = scsiback_check_false,
1783         .tpg_get_inst_index             = scsiback_tpg_get_inst_index,
1784         .check_stop_free                = scsiback_check_stop_free,
1785         .release_cmd                    = scsiback_release_cmd,
1786         .sess_get_index                 = scsiback_sess_get_index,
1787         .sess_get_initiator_sid         = NULL,
1788         .write_pending                  = scsiback_write_pending,
1789         .set_default_node_attributes    = scsiback_set_default_node_attrs,
1790         .get_cmd_state                  = scsiback_get_cmd_state,
1791         .queue_data_in                  = scsiback_queue_data_in,
1792         .queue_status                   = scsiback_queue_status,
1793         .queue_tm_rsp                   = scsiback_queue_tm_rsp,
1794         .aborted_task                   = scsiback_aborted_task,
1795         /*
1796          * Setup callers for generic logic in target_core_fabric_configfs.c
1797          */
1798         .fabric_make_wwn                = scsiback_make_tport,
1799         .fabric_drop_wwn                = scsiback_drop_tport,
1800         .fabric_make_tpg                = scsiback_make_tpg,
1801         .fabric_drop_tpg                = scsiback_drop_tpg,
1802         .fabric_post_link               = scsiback_port_link,
1803         .fabric_pre_unlink              = scsiback_port_unlink,
1804
1805         .tfc_wwn_attrs                  = scsiback_wwn_attrs,
1806         .tfc_tpg_base_attrs             = scsiback_tpg_attrs,
1807         .tfc_tpg_param_attrs            = scsiback_param_attrs,
1808 };
1809
1810 static const struct xenbus_device_id scsiback_ids[] = {
1811         { "vscsi" },
1812         { "" }
1813 };
1814
1815 static struct xenbus_driver scsiback_driver = {
1816         .ids                    = scsiback_ids,
1817         .probe                  = scsiback_probe,
1818         .remove                 = scsiback_remove,
1819         .otherend_changed       = scsiback_frontend_changed
1820 };
1821
1822 static int __init scsiback_init(void)
1823 {
1824         int ret;
1825
1826         if (!xen_domain())
1827                 return -ENODEV;
1828
1829         pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
1830                  VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1831
1832         ret = xenbus_register_backend(&scsiback_driver);
1833         if (ret)
1834                 goto out;
1835
1836         ret = target_register_template(&scsiback_ops);
1837         if (ret)
1838                 goto out_unregister_xenbus;
1839
1840         return 0;
1841
1842 out_unregister_xenbus:
1843         xenbus_unregister_driver(&scsiback_driver);
1844 out:
1845         pr_err("%s: error %d\n", __func__, ret);
1846         return ret;
1847 }
1848
1849 static void __exit scsiback_exit(void)
1850 {
1851         target_unregister_template(&scsiback_ops);
1852         xenbus_unregister_driver(&scsiback_driver);
1853 }
1854
1855 module_init(scsiback_init);
1856 module_exit(scsiback_exit);
1857
1858 MODULE_DESCRIPTION("Xen SCSI backend driver");
1859 MODULE_LICENSE("Dual BSD/GPL");
1860 MODULE_ALIAS("xen-backend:vscsi");
1861 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");