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