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 #include <stdarg.h>
  35
  36 #include <linux/module.h>
  37 #include <linux/utsname.h>
  38 #include <linux/interrupt.h>
  39 #include <linux/slab.h>
  40 #include <linux/wait.h>
  41 #include <linux/sched.h>
  42 #include <linux/list.h>
  43 #include <linux/gfp.h>
  44 #include <linux/delay.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/configfs.h>
  47
  48 #include <generated/utsrelease.h>
  49
  50 #include <scsi/scsi_dbg.h>
  51 #include <scsi/scsi_eh.h>
  52 #include <scsi/scsi_tcq.h>
  53
  54 #include <target/target_core_base.h>
  55 #include <target/target_core_fabric.h>
  56 #include <target/target_core_configfs.h>
  57 #include <target/target_core_fabric_configfs.h>
  58
  59 #include <asm/hypervisor.h>
  60
  61 #include <xen/xen.h>
  62 #include <xen/balloon.h>
  63 #include <xen/events.h>
  64 #include <xen/xenbus.h>
  65 #include <xen/grant_table.h>
  66 #include <xen/page.h>
  67
  68 #include <xen/interface/grant_table.h>
  69 #include <xen/interface/io/vscsiif.h>
  70
  71 #define DPRINTK(_f, _a...)                      \
  72         pr_debug("(file=%s, line=%d) " _f, __FILE__ , __LINE__ , ## _a)
  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 /* Local pointer to allocated TCM configfs fabric module */
 208 static struct target_fabric_configfs *scsiback_fabric_configfs;
 209
 210 static void scsiback_get(struct vscsibk_info *info)
 211 {
 212         atomic_inc(&info->nr_unreplied_reqs);
 213 }
 214
 215 static void scsiback_put(struct vscsibk_info *info)
 216 {
 217         if (atomic_dec_and_test(&info->nr_unreplied_reqs))
 218                 wake_up(&info->waiting_to_free);
 219 }
 220
 221 static void put_free_pages(struct page **page, int num)
 222 {
 223         unsigned long flags;
 224         int i = free_pages_num + num, n = num;
 225
 226         if (num == 0)
 227                 return;
 228         if (i > scsiback_max_buffer_pages) {
 229                 n = min(num, i - scsiback_max_buffer_pages);
 230                 gnttab_free_pages(n, page + num - n);
 231                 n = num - n;
 232         }
 233         spin_lock_irqsave(&free_pages_lock, flags);
 234         for (i = 0; i < n; i++)
 235                 list_add(&page[i]->lru, &scsiback_free_pages);
 236         free_pages_num += n;
 237         spin_unlock_irqrestore(&free_pages_lock, flags);
 238 }
 239
 240 static int get_free_page(struct page **page)
 241 {
 242         unsigned long flags;
 243
 244         spin_lock_irqsave(&free_pages_lock, flags);
 245         if (list_empty(&scsiback_free_pages)) {
 246                 spin_unlock_irqrestore(&free_pages_lock, flags);
 247                 return gnttab_alloc_pages(1, page);
 248         }
 249         page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
 250         list_del(&page[0]->lru);
 251         free_pages_num--;
 252         spin_unlock_irqrestore(&free_pages_lock, flags);
 253         return 0;
 254 }
 255
 256 static unsigned long vaddr_page(struct page *page)
 257 {
 258         unsigned long pfn = page_to_pfn(page);
 259
 260         return (unsigned long)pfn_to_kaddr(pfn);
 261 }
 262
 263 static unsigned long vaddr(struct vscsibk_pend *req, int seg)
 264 {
 265         return vaddr_page(req->pages[seg]);
 266 }
 267
 268 static void scsiback_print_status(char *sense_buffer, int errors,
 269                                         struct vscsibk_pend *pending_req)
 270 {
 271         struct scsiback_tpg *tpg = pending_req->v2p->tpg;
 272
 273         pr_err("xen-pvscsi[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n",
 274                tpg->tport->tport_name, pending_req->v2p->lun,
 275                pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
 276                host_byte(errors), driver_byte(errors));
 277 }
 278
 279 static void scsiback_fast_flush_area(struct vscsibk_pend *req)
 280 {
 281         struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
 282         struct page *pages[VSCSI_GRANT_BATCH];
 283         unsigned int i, invcount = 0;
 284         grant_handle_t handle;
 285         int err;
 286
 287         kfree(req->sgl);
 288         req->sgl = NULL;
 289         req->n_sg = 0;
 290
 291         if (!req->n_grants)
 292                 return;
 293
 294         for (i = 0; i < req->n_grants; i++) {
 295                 handle = req->grant_handles[i];
 296                 if (handle == SCSIBACK_INVALID_HANDLE)
 297                         continue;
 298                 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
 299                                     GNTMAP_host_map, handle);
 300                 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
 301                 pages[invcount] = req->pages[i];
 302                 put_page(pages[invcount]);
 303                 invcount++;
 304                 if (invcount < VSCSI_GRANT_BATCH)
 305                         continue;
 306                 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
 307                 BUG_ON(err);
 308                 invcount = 0;
 309         }
 310
 311         if (invcount) {
 312                 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
 313                 BUG_ON(err);
 314         }
 315
 316         put_free_pages(req->pages, req->n_grants);
 317         req->n_grants = 0;
 318 }
 319
 320 static void scsiback_free_translation_entry(struct kref *kref)
 321 {
 322         struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
 323         struct scsiback_tpg *tpg = entry->tpg;
 324
 325         mutex_lock(&tpg->tv_tpg_mutex);
 326         tpg->tv_tpg_fe_count--;
 327         mutex_unlock(&tpg->tv_tpg_mutex);
 328
 329         kfree(entry);
 330 }
 331
 332 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
 333                         uint32_t resid, struct vscsibk_pend *pending_req)
 334 {
 335         struct vscsiif_response *ring_res;
 336         struct vscsibk_info *info = pending_req->info;
 337         int notify;
 338         struct scsi_sense_hdr sshdr;
 339         unsigned long flags;
 340         unsigned len;
 341
 342         spin_lock_irqsave(&info->ring_lock, flags);
 343
 344         ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
 345         info->ring.rsp_prod_pvt++;
 346
 347         ring_res->rslt   = result;
 348         ring_res->rqid   = pending_req->rqid;
 349
 350         if (sense_buffer != NULL &&
 351             scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
 352                                  &sshdr)) {
 353                 len = min_t(unsigned, 8 + sense_buffer[7],
 354                             VSCSIIF_SENSE_BUFFERSIZE);
 355                 memcpy(ring_res->sense_buffer, sense_buffer, len);
 356                 ring_res->sense_len = len;
 357         } else {
 358                 ring_res->sense_len = 0;
 359         }
 360
 361         ring_res->residual_len = resid;
 362
 363         RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
 364         spin_unlock_irqrestore(&info->ring_lock, flags);
 365
 366         if (notify)
 367                 notify_remote_via_irq(info->irq);
 368
 369         if (pending_req->v2p)
 370                 kref_put(&pending_req->v2p->kref,
 371                          scsiback_free_translation_entry);
 372 }
 373
 374 static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
 375 {
 376         struct vscsibk_info *info = pending_req->info;
 377         unsigned char *sense_buffer;
 378         unsigned int resid;
 379         int errors;
 380
 381         sense_buffer = pending_req->sense_buffer;
 382         resid        = pending_req->se_cmd.residual_count;
 383         errors       = pending_req->result;
 384
 385         if (errors && log_print_stat)
 386                 scsiback_print_status(sense_buffer, errors, pending_req);
 387
 388         scsiback_fast_flush_area(pending_req);
 389         scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
 390         scsiback_put(info);
 391 }
 392
 393 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
 394 {
 395         struct se_cmd *se_cmd = &pending_req->se_cmd;
 396         struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
 397         int rc;
 398
 399         memset(pending_req->sense_buffer, 0, VSCSIIF_SENSE_BUFFERSIZE);
 400
 401         memset(se_cmd, 0, sizeof(*se_cmd));
 402
 403         scsiback_get(pending_req->info);
 404         rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
 405                         pending_req->sense_buffer, pending_req->v2p->lun,
 406                         pending_req->data_len, 0,
 407                         pending_req->sc_data_direction, 0,
 408                         pending_req->sgl, pending_req->n_sg,
 409                         NULL, 0, NULL, 0);
 410         if (rc < 0) {
 411                 transport_send_check_condition_and_sense(se_cmd,
 412                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 413                 transport_generic_free_cmd(se_cmd, 0);
 414         }
 415 }
 416
 417 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
 418         struct page **pg, grant_handle_t *grant, int cnt)
 419 {
 420         int err, i;
 421
 422         if (!cnt)
 423                 return 0;
 424
 425         err = gnttab_map_refs(map, NULL, pg, cnt);
 426         BUG_ON(err);
 427         for (i = 0; i < cnt; i++) {
 428                 if (unlikely(map[i].status != GNTST_okay)) {
 429                         pr_err("xen-pvscsi: invalid buffer -- could not remap it\n");
 430                         map[i].handle = SCSIBACK_INVALID_HANDLE;
 431                         err = -ENOMEM;
 432                 } else {
 433                         get_page(pg[i]);
 434                 }
 435                 grant[i] = map[i].handle;
 436         }
 437         return err;
 438 }
 439
 440 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
 441                         struct scsiif_request_segment *seg, struct page **pg,
 442                         grant_handle_t *grant, int cnt, u32 flags)
 443 {
 444         int mapcount = 0, i, err = 0;
 445         struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
 446         struct vscsibk_info *info = pending_req->info;
 447
 448         for (i = 0; i < cnt; i++) {
 449                 if (get_free_page(pg + mapcount)) {
 450                         put_free_pages(pg, mapcount);
 451                         pr_err("xen-pvscsi: no grant page\n");
 452                         return -ENOMEM;
 453                 }
 454                 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
 455                                   flags, seg[i].gref, info->domid);
 456                 mapcount++;
 457                 if (mapcount < VSCSI_GRANT_BATCH)
 458                         continue;
 459                 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
 460                 pg += mapcount;
 461                 grant += mapcount;
 462                 pending_req->n_grants += mapcount;
 463                 if (err)
 464                         return err;
 465                 mapcount = 0;
 466         }
 467         err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
 468         pending_req->n_grants += mapcount;
 469         return err;
 470 }
 471
 472 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
 473                                         struct vscsibk_pend *pending_req)
 474 {
 475         u32 flags;
 476         int i, err, n_segs, i_seg = 0;
 477         struct page **pg;
 478         struct scsiif_request_segment *seg;
 479         unsigned long end_seg = 0;
 480         unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
 481         unsigned int nr_sgl = 0;
 482         struct scatterlist *sg;
 483         grant_handle_t *grant;
 484
 485         pending_req->n_sg = 0;
 486         pending_req->n_grants = 0;
 487         pending_req->data_len = 0;
 488
 489         nr_segments &= ~VSCSIIF_SG_GRANT;
 490         if (!nr_segments)
 491                 return 0;
 492
 493         if (nr_segments > VSCSIIF_SG_TABLESIZE) {
 494                 DPRINTK("xen-pvscsi: invalid parameter nr_seg = %d\n",
 495                         ring_req->nr_segments);
 496                 return -EINVAL;
 497         }
 498
 499         if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
 500                 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
 501                         pending_req->pages, pending_req->grant_handles,
 502                         nr_segments, GNTMAP_host_map | GNTMAP_readonly);
 503                 if (err)
 504                         return err;
 505                 nr_sgl = nr_segments;
 506                 nr_segments = 0;
 507                 for (i = 0; i < nr_sgl; i++) {
 508                         n_segs = ring_req->seg[i].length /
 509                                  sizeof(struct scsiif_request_segment);
 510                         if ((unsigned)ring_req->seg[i].offset +
 511                             (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
 512                             n_segs * sizeof(struct scsiif_request_segment) !=
 513                             ring_req->seg[i].length)
 514                                 return -EINVAL;
 515                         nr_segments += n_segs;
 516                 }
 517                 if (nr_segments > SG_ALL) {
 518                         DPRINTK("xen-pvscsi: invalid nr_seg = %d\n",
 519                                 nr_segments);
 520                         return -EINVAL;
 521                 }
 522         }
 523
 524         /* free of (sgl) in fast_flush_area()*/
 525         pending_req->sgl = kmalloc_array(nr_segments,
 526                                         sizeof(struct scatterlist), GFP_KERNEL);
 527         if (!pending_req->sgl)
 528                 return -ENOMEM;
 529
 530         sg_init_table(pending_req->sgl, nr_segments);
 531         pending_req->n_sg = nr_segments;
 532
 533         flags = GNTMAP_host_map;
 534         if (pending_req->sc_data_direction == DMA_TO_DEVICE)
 535                 flags |= GNTMAP_readonly;
 536
 537         pg = pending_req->pages + nr_sgl;
 538         grant = pending_req->grant_handles + nr_sgl;
 539         if (!nr_sgl) {
 540                 seg = ring_req->seg;
 541                 err = scsiback_gnttab_data_map_list(pending_req, seg,
 542                         pg, grant, nr_segments, flags);
 543                 if (err)
 544                         return err;
 545         } else {
 546                 for (i = 0; i < nr_sgl; i++) {
 547                         seg = (struct scsiif_request_segment *)(
 548                               vaddr(pending_req, i) + ring_req->seg[i].offset);
 549                         n_segs = ring_req->seg[i].length /
 550                                  sizeof(struct scsiif_request_segment);
 551                         err = scsiback_gnttab_data_map_list(pending_req, seg,
 552                                 pg, grant, n_segs, flags);
 553                         if (err)
 554                                 return err;
 555                         pg += n_segs;
 556                         grant += n_segs;
 557                 }
 558                 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
 559                 seg = (struct scsiif_request_segment *)end_seg;
 560                 end_seg += ring_req->seg[0].length;
 561                 pg = pending_req->pages + nr_sgl;
 562         }
 563
 564         for_each_sg(pending_req->sgl, sg, nr_segments, i) {
 565                 sg_set_page(sg, pg[i], seg->length, seg->offset);
 566                 pending_req->data_len += seg->length;
 567                 seg++;
 568                 if (nr_sgl && (unsigned long)seg >= end_seg) {
 569                         i_seg++;
 570                         end_seg = vaddr(pending_req, i_seg) +
 571                                   ring_req->seg[i_seg].offset;
 572                         seg = (struct scsiif_request_segment *)end_seg;
 573                         end_seg += ring_req->seg[i_seg].length;
 574                 }
 575                 if (sg->offset >= PAGE_SIZE ||
 576                     sg->length > PAGE_SIZE ||
 577                     sg->offset + sg->length > PAGE_SIZE)
 578                         return -EINVAL;
 579         }
 580
 581         return 0;
 582 }
 583
 584 static void scsiback_disconnect(struct vscsibk_info *info)
 585 {
 586         wait_event(info->waiting_to_free,
 587                 atomic_read(&info->nr_unreplied_reqs) == 0);
 588
 589         unbind_from_irqhandler(info->irq, info);
 590         info->irq = 0;
 591         xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
 592 }
 593
 594 static void scsiback_device_action(struct vscsibk_pend *pending_req,
 595         enum tcm_tmreq_table act, int tag)
 596 {
 597         int rc, err = FAILED;
 598         struct scsiback_tpg *tpg = pending_req->v2p->tpg;
 599         struct se_cmd *se_cmd = &pending_req->se_cmd;
 600         struct scsiback_tmr *tmr;
 601
 602         tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
 603         if (!tmr)
 604                 goto out;
 605
 606         init_waitqueue_head(&tmr->tmr_wait);
 607
 608         transport_init_se_cmd(se_cmd, tpg->se_tpg.se_tpg_tfo,
 609                 tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, TCM_SIMPLE_TAG,
 610                 &pending_req->sense_buffer[0]);
 611
 612         rc = core_tmr_alloc_req(se_cmd, tmr, act, GFP_KERNEL);
 613         if (rc < 0)
 614                 goto out;
 615
 616         se_cmd->se_tmr_req->ref_task_tag = tag;
 617
 618         if (transport_lookup_tmr_lun(se_cmd, pending_req->v2p->lun) < 0)
 619                 goto out;
 620
 621         transport_generic_handle_tmr(se_cmd);
 622         wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
 623
 624         err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
 625                 SUCCESS : FAILED;
 626
 627 out:
 628         if (tmr) {
 629                 transport_generic_free_cmd(&pending_req->se_cmd, 1);
 630                 kfree(tmr);
 631         }
 632
 633         scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
 634
 635         kmem_cache_free(scsiback_cachep, pending_req);
 636 }
 637
 638 /*
 639   Perform virtual to physical translation
 640 */
 641 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
 642                         struct ids_tuple *v)
 643 {
 644         struct v2p_entry *entry;
 645         struct list_head *head = &(info->v2p_entry_lists);
 646         unsigned long flags;
 647
 648         spin_lock_irqsave(&info->v2p_lock, flags);
 649         list_for_each_entry(entry, head, l) {
 650                 if ((entry->v.chn == v->chn) &&
 651                     (entry->v.tgt == v->tgt) &&
 652                     (entry->v.lun == v->lun)) {
 653                         kref_get(&entry->kref);
 654                         goto out;
 655                 }
 656         }
 657         entry = NULL;
 658
 659 out:
 660         spin_unlock_irqrestore(&info->v2p_lock, flags);
 661         return entry;
 662 }
 663
 664 static int prepare_pending_reqs(struct vscsibk_info *info,
 665                                 struct vscsiif_request *ring_req,
 666                                 struct vscsibk_pend *pending_req)
 667 {
 668         struct v2p_entry *v2p;
 669         struct ids_tuple vir;
 670
 671         pending_req->rqid       = ring_req->rqid;
 672         pending_req->info       = info;
 673
 674         vir.chn = ring_req->channel;
 675         vir.tgt = ring_req->id;
 676         vir.lun = ring_req->lun;
 677
 678         v2p = scsiback_do_translation(info, &vir);
 679         if (!v2p) {
 680                 pending_req->v2p = NULL;
 681                 DPRINTK("xen-pvscsi: doesn't exist.\n");
 682                 return -ENODEV;
 683         }
 684         pending_req->v2p = v2p;
 685
 686         /* request range check from frontend */
 687         pending_req->sc_data_direction = ring_req->sc_data_direction;
 688         if ((pending_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
 689                 (pending_req->sc_data_direction != DMA_TO_DEVICE) &&
 690                 (pending_req->sc_data_direction != DMA_FROM_DEVICE) &&
 691                 (pending_req->sc_data_direction != DMA_NONE)) {
 692                 DPRINTK("xen-pvscsi: invalid parameter data_dir = %d\n",
 693                         pending_req->sc_data_direction);
 694                 return -EINVAL;
 695         }
 696
 697         pending_req->cmd_len = ring_req->cmd_len;
 698         if (pending_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
 699                 DPRINTK("xen-pvscsi: invalid parameter cmd_len = %d\n",
 700                         pending_req->cmd_len);
 701                 return -EINVAL;
 702         }
 703         memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
 704
 705         return 0;
 706 }
 707
 708 static int scsiback_do_cmd_fn(struct vscsibk_info *info)
 709 {
 710         struct vscsiif_back_ring *ring = &info->ring;
 711         struct vscsiif_request *ring_req;
 712         struct vscsibk_pend *pending_req;
 713         RING_IDX rc, rp;
 714         int err, more_to_do;
 715         uint32_t result;
 716         uint8_t act;
 717
 718         rc = ring->req_cons;
 719         rp = ring->sring->req_prod;
 720         rmb();  /* guest system is accessing ring, too */
 721
 722         if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
 723                 rc = ring->rsp_prod_pvt;
 724                 pr_warn("xen-pvscsi: Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
 725                            info->domid, rp, rc, rp - rc);
 726                 info->ring_error = 1;
 727                 return 0;
 728         }
 729
 730         while ((rc != rp)) {
 731                 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
 732                         break;
 733                 pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL);
 734                 if (!pending_req)
 735                         return 1;
 736
 737                 ring_req = RING_GET_REQUEST(ring, rc);
 738                 ring->req_cons = ++rc;
 739
 740                 act = ring_req->act;
 741                 err = prepare_pending_reqs(info, ring_req, pending_req);
 742                 if (err) {
 743                         switch (err) {
 744                         case -ENODEV:
 745                                 result = DID_NO_CONNECT;
 746                                 break;
 747                         default:
 748                                 result = DRIVER_ERROR;
 749                                 break;
 750                         }
 751                         scsiback_do_resp_with_sense(NULL, result << 24, 0,
 752                                                     pending_req);
 753                         kmem_cache_free(scsiback_cachep, pending_req);
 754                         return 1;
 755                 }
 756
 757                 switch (act) {
 758                 case VSCSIIF_ACT_SCSI_CDB:
 759                         if (scsiback_gnttab_data_map(ring_req, pending_req)) {
 760                                 scsiback_fast_flush_area(pending_req);
 761                                 scsiback_do_resp_with_sense(NULL,
 762                                         DRIVER_ERROR << 24, 0, pending_req);
 763                                 kmem_cache_free(scsiback_cachep, pending_req);
 764                         } else {
 765                                 scsiback_cmd_exec(pending_req);
 766                         }
 767                         break;
 768                 case VSCSIIF_ACT_SCSI_ABORT:
 769                         scsiback_device_action(pending_req, TMR_ABORT_TASK,
 770                                 ring_req->ref_rqid);
 771                         break;
 772                 case VSCSIIF_ACT_SCSI_RESET:
 773                         scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
 774                         break;
 775                 default:
 776                         pr_err_ratelimited("xen-pvscsi: invalid request\n");
 777                         scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24,
 778                                                     0, pending_req);
 779                         kmem_cache_free(scsiback_cachep, pending_req);
 780                         break;
 781                 }
 782
 783                 /* Yield point for this unbounded loop. */
 784                 cond_resched();
 785         }
 786
 787         RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
 788         return more_to_do;
 789 }
 790
 791 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
 792 {
 793         struct vscsibk_info *info = dev_id;
 794
 795         if (info->ring_error)
 796                 return IRQ_HANDLED;
 797
 798         while (scsiback_do_cmd_fn(info))
 799                 cond_resched();
 800
 801         return IRQ_HANDLED;
 802 }
 803
 804 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
 805                         evtchn_port_t evtchn)
 806 {
 807         void *area;
 808         struct vscsiif_sring *sring;
 809         int err;
 810
 811         if (info->irq)
 812                 return -1;
 813
 814         err = xenbus_map_ring_valloc(info->dev, ring_ref, &area);
 815         if (err)
 816                 return err;
 817
 818         sring = (struct vscsiif_sring *)area;
 819         BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
 820
 821         err = bind_interdomain_evtchn_to_irq(info->domid, evtchn);
 822         if (err < 0)
 823                 goto unmap_page;
 824
 825         info->irq = err;
 826
 827         err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
 828                                    IRQF_ONESHOT, "vscsiif-backend", info);
 829         if (err)
 830                 goto free_irq;
 831
 832         return 0;
 833
 834 free_irq:
 835         unbind_from_irqhandler(info->irq, info);
 836         info->irq = 0;
 837 unmap_page:
 838         xenbus_unmap_ring_vfree(info->dev, area);
 839
 840         return err;
 841 }
 842
 843 static int scsiback_map(struct vscsibk_info *info)
 844 {
 845         struct xenbus_device *dev = info->dev;
 846         unsigned int ring_ref, evtchn;
 847         int err;
 848
 849         err = xenbus_gather(XBT_NIL, dev->otherend,
 850                         "ring-ref", "%u", &ring_ref,
 851                         "event-channel", "%u", &evtchn, NULL);
 852         if (err) {
 853                 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
 854                 return err;
 855         }
 856
 857         return scsiback_init_sring(info, ring_ref, evtchn);
 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 *entry;
 868         struct v2p_entry *new;
 869         struct list_head *head = &(info->v2p_entry_lists);
 870         unsigned long flags;
 871         char *lunp;
 872         unsigned int lun;
 873         struct scsiback_tpg *tpg_entry, *tpg = NULL;
 874         char *error = "doesn't exist";
 875
 876         lunp = strrchr(phy, ':');
 877         if (!lunp) {
 878                 pr_err("xen-pvscsi: illegal format of physical device %s\n",
 879                         phy);
 880                 return -EINVAL;
 881         }
 882         *lunp = 0;
 883         lunp++;
 884         if (kstrtouint(lunp, 10, &lun) || lun >= TRANSPORT_MAX_LUNS_PER_TPG) {
 885                 pr_err("xen-pvscsi: lun number not valid: %s\n", lunp);
 886                 return -EINVAL;
 887         }
 888
 889         mutex_lock(&scsiback_mutex);
 890         list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
 891                 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
 892                     !strcmp(phy, tpg_entry->param_alias)) {
 893                         spin_lock(&tpg_entry->se_tpg.tpg_lun_lock);
 894                         if (tpg_entry->se_tpg.tpg_lun_list[lun]->lun_status ==
 895                             TRANSPORT_LUN_STATUS_ACTIVE) {
 896                                 if (!tpg_entry->tpg_nexus)
 897                                         error = "nexus undefined";
 898                                 else
 899                                         tpg = tpg_entry;
 900                         }
 901                         spin_unlock(&tpg_entry->se_tpg.tpg_lun_lock);
 902                         break;
 903                 }
 904         }
 905         if (tpg) {
 906                 mutex_lock(&tpg->tv_tpg_mutex);
 907                 tpg->tv_tpg_fe_count++;
 908                 mutex_unlock(&tpg->tv_tpg_mutex);
 909         }
 910         mutex_unlock(&scsiback_mutex);
 911
 912         if (!tpg) {
 913                 pr_err("xen-pvscsi: %s:%d %s\n", phy, lun, error);
 914                 return -ENODEV;
 915         }
 916
 917         new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
 918         if (new == NULL) {
 919                 err = -ENOMEM;
 920                 goto out_free;
 921         }
 922
 923         spin_lock_irqsave(&info->v2p_lock, flags);
 924
 925         /* Check double assignment to identical virtual ID */
 926         list_for_each_entry(entry, head, l) {
 927                 if ((entry->v.chn == v->chn) &&
 928                     (entry->v.tgt == v->tgt) &&
 929                     (entry->v.lun == v->lun)) {
 930                         pr_warn("xen-pvscsi: Virtual ID is already used. Assignment was not performed.\n");
 931                         err = -EEXIST;
 932                         goto out;
 933                 }
 934
 935         }
 936
 937         /* Create a new translation entry and add to the list */
 938         kref_init(&new->kref);
 939         new->v = *v;
 940         new->tpg = tpg;
 941         new->lun = lun;
 942         list_add_tail(&new->l, head);
 943
 944 out:
 945         spin_unlock_irqrestore(&info->v2p_lock, flags);
 946
 947 out_free:
 948         mutex_lock(&tpg->tv_tpg_mutex);
 949         tpg->tv_tpg_fe_count--;
 950         mutex_unlock(&tpg->tv_tpg_mutex);
 951
 952         if (err)
 953                 kfree(new);
 954
 955         return err;
 956 }
 957
 958 static void __scsiback_del_translation_entry(struct v2p_entry *entry)
 959 {
 960         list_del(&entry->l);
 961         kref_put(&entry->kref, scsiback_free_translation_entry);
 962 }
 963
 964 /*
 965   Delete the translation entry specfied
 966 */
 967 static int scsiback_del_translation_entry(struct vscsibk_info *info,
 968                                           struct ids_tuple *v)
 969 {
 970         struct v2p_entry *entry;
 971         struct list_head *head = &(info->v2p_entry_lists);
 972         unsigned long flags;
 973
 974         spin_lock_irqsave(&info->v2p_lock, flags);
 975         /* Find out the translation entry specified */
 976         list_for_each_entry(entry, head, l) {
 977                 if ((entry->v.chn == v->chn) &&
 978                     (entry->v.tgt == v->tgt) &&
 979                     (entry->v.lun == v->lun)) {
 980                         goto found;
 981                 }
 982         }
 983
 984         spin_unlock_irqrestore(&info->v2p_lock, flags);
 985         return 1;
 986
 987 found:
 988         /* Delete the translation entry specfied */
 989         __scsiback_del_translation_entry(entry);
 990
 991         spin_unlock_irqrestore(&info->v2p_lock, flags);
 992         return 0;
 993 }
 994
 995 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
 996                                 char *phy, struct ids_tuple *vir)
 997 {
 998         if (!scsiback_add_translation_entry(info, phy, vir)) {
 999                 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1000                                   "%d", XenbusStateInitialised)) {
1001                         pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1002                         scsiback_del_translation_entry(info, vir);
1003                 }
1004         } else {
1005                 xenbus_printf(XBT_NIL, info->dev->nodename, state,
1006                               "%d", XenbusStateClosed);
1007         }
1008 }
1009
1010 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1011                                 struct ids_tuple *vir)
1012 {
1013         if (!scsiback_del_translation_entry(info, vir)) {
1014                 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1015                                   "%d", XenbusStateClosed))
1016                         pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1017         }
1018 }
1019
1020 #define VSCSIBACK_OP_ADD_OR_DEL_LUN     1
1021 #define VSCSIBACK_OP_UPDATEDEV_STATE    2
1022
1023 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1024                                      char *ent)
1025 {
1026         int err;
1027         struct ids_tuple vir;
1028         char *val;
1029         int device_state;
1030         char phy[VSCSI_NAMELEN];
1031         char str[64];
1032         char state[64];
1033         struct xenbus_device *dev = info->dev;
1034
1035         /* read status */
1036         snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1037         err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1038         if (XENBUS_EXIST_ERR(err))
1039                 return;
1040
1041         /* physical SCSI device */
1042         snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1043         val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1044         if (IS_ERR(val)) {
1045                 xenbus_printf(XBT_NIL, dev->nodename, state,
1046                               "%d", XenbusStateClosed);
1047                 return;
1048         }
1049         strlcpy(phy, val, VSCSI_NAMELEN);
1050         kfree(val);
1051
1052         /* virtual SCSI device */
1053         snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1054         err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1055                            &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1056         if (XENBUS_EXIST_ERR(err)) {
1057                 xenbus_printf(XBT_NIL, dev->nodename, state,
1058                               "%d", XenbusStateClosed);
1059                 return;
1060         }
1061
1062         switch (op) {
1063         case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1064                 if (device_state == XenbusStateInitialising)
1065                         scsiback_do_add_lun(info, state, phy, &vir);
1066                 if (device_state == XenbusStateClosing)
1067                         scsiback_do_del_lun(info, state, &vir);
1068                 break;
1069
1070         case VSCSIBACK_OP_UPDATEDEV_STATE:
1071                 if (device_state == XenbusStateInitialised) {
1072                         /* modify vscsi-devs/dev-x/state */
1073                         if (xenbus_printf(XBT_NIL, dev->nodename, state,
1074                                           "%d", XenbusStateConnected)) {
1075                                 pr_err("xen-pvscsi: xenbus_printf error %s\n",
1076                                        str);
1077                                 scsiback_del_translation_entry(info, &vir);
1078                                 xenbus_printf(XBT_NIL, dev->nodename, state,
1079                                               "%d", XenbusStateClosed);
1080                         }
1081                 }
1082                 break;
1083         /*When it is necessary, processing is added here.*/
1084         default:
1085                 break;
1086         }
1087 }
1088
1089 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1090 {
1091         int i;
1092         char **dir;
1093         unsigned int ndir = 0;
1094
1095         dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1096                                &ndir);
1097         if (IS_ERR(dir))
1098                 return;
1099
1100         for (i = 0; i < ndir; i++)
1101                 scsiback_do_1lun_hotplug(info, op, dir[i]);
1102
1103         kfree(dir);
1104 }
1105
1106 static void scsiback_frontend_changed(struct xenbus_device *dev,
1107                                         enum xenbus_state frontend_state)
1108 {
1109         struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1110
1111         switch (frontend_state) {
1112         case XenbusStateInitialising:
1113                 break;
1114
1115         case XenbusStateInitialised:
1116                 if (scsiback_map(info))
1117                         break;
1118
1119                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1120                 xenbus_switch_state(dev, XenbusStateConnected);
1121                 break;
1122
1123         case XenbusStateConnected:
1124                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1125
1126                 if (dev->state == XenbusStateConnected)
1127                         break;
1128
1129                 xenbus_switch_state(dev, XenbusStateConnected);
1130                 break;
1131
1132         case XenbusStateClosing:
1133                 if (info->irq)
1134                         scsiback_disconnect(info);
1135
1136                 xenbus_switch_state(dev, XenbusStateClosing);
1137                 break;
1138
1139         case XenbusStateClosed:
1140                 xenbus_switch_state(dev, XenbusStateClosed);
1141                 if (xenbus_dev_is_online(dev))
1142                         break;
1143                 /* fall through if not online */
1144         case XenbusStateUnknown:
1145                 device_unregister(&dev->dev);
1146                 break;
1147
1148         case XenbusStateReconfiguring:
1149                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1150                 xenbus_switch_state(dev, XenbusStateReconfigured);
1151
1152                 break;
1153
1154         default:
1155                 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1156                                         frontend_state);
1157                 break;
1158         }
1159 }
1160
1161 /*
1162   Release the translation entry specfied
1163 */
1164 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1165 {
1166         struct v2p_entry *entry, *tmp;
1167         struct list_head *head = &(info->v2p_entry_lists);
1168         unsigned long flags;
1169
1170         spin_lock_irqsave(&info->v2p_lock, flags);
1171
1172         list_for_each_entry_safe(entry, tmp, head, l)
1173                 __scsiback_del_translation_entry(entry);
1174
1175         spin_unlock_irqrestore(&info->v2p_lock, flags);
1176 }
1177
1178 static int scsiback_remove(struct xenbus_device *dev)
1179 {
1180         struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1181
1182         if (info->irq)
1183                 scsiback_disconnect(info);
1184
1185         scsiback_release_translation_entry(info);
1186
1187         dev_set_drvdata(&dev->dev, NULL);
1188
1189         return 0;
1190 }
1191
1192 static int scsiback_probe(struct xenbus_device *dev,
1193                            const struct xenbus_device_id *id)
1194 {
1195         int err;
1196
1197         struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1198                                             GFP_KERNEL);
1199
1200         DPRINTK("%p %d\n", dev, dev->otherend_id);
1201
1202         if (!info) {
1203                 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1204                 return -ENOMEM;
1205         }
1206         info->dev = dev;
1207         dev_set_drvdata(&dev->dev, info);
1208
1209         info->domid = dev->otherend_id;
1210         spin_lock_init(&info->ring_lock);
1211         info->ring_error = 0;
1212         atomic_set(&info->nr_unreplied_reqs, 0);
1213         init_waitqueue_head(&info->waiting_to_free);
1214         info->dev = dev;
1215         info->irq = 0;
1216         INIT_LIST_HEAD(&info->v2p_entry_lists);
1217         spin_lock_init(&info->v2p_lock);
1218
1219         err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1220                             SG_ALL);
1221         if (err)
1222                 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1223
1224         err = xenbus_switch_state(dev, XenbusStateInitWait);
1225         if (err)
1226                 goto fail;
1227
1228         return 0;
1229
1230 fail:
1231         pr_warn("xen-pvscsi: %s failed\n", __func__);
1232         scsiback_remove(dev);
1233
1234         return err;
1235 }
1236
1237 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1238 {
1239         switch (tport->tport_proto_id) {
1240         case SCSI_PROTOCOL_SAS:
1241                 return "SAS";
1242         case SCSI_PROTOCOL_FCP:
1243                 return "FCP";
1244         case SCSI_PROTOCOL_ISCSI:
1245                 return "iSCSI";
1246         default:
1247                 break;
1248         }
1249
1250         return "Unknown";
1251 }
1252
1253 static u8 scsiback_get_fabric_proto_ident(struct se_portal_group *se_tpg)
1254 {
1255         struct scsiback_tpg *tpg = container_of(se_tpg,
1256                                 struct scsiback_tpg, se_tpg);
1257         struct scsiback_tport *tport = tpg->tport;
1258
1259         switch (tport->tport_proto_id) {
1260         case SCSI_PROTOCOL_SAS:
1261                 return sas_get_fabric_proto_ident(se_tpg);
1262         case SCSI_PROTOCOL_FCP:
1263                 return fc_get_fabric_proto_ident(se_tpg);
1264         case SCSI_PROTOCOL_ISCSI:
1265                 return iscsi_get_fabric_proto_ident(se_tpg);
1266         default:
1267                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1268                         tport->tport_proto_id);
1269                 break;
1270         }
1271
1272         return sas_get_fabric_proto_ident(se_tpg);
1273 }
1274
1275 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1276 {
1277         struct scsiback_tpg *tpg = container_of(se_tpg,
1278                                 struct scsiback_tpg, se_tpg);
1279         struct scsiback_tport *tport = tpg->tport;
1280
1281         return &tport->tport_name[0];
1282 }
1283
1284 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1285 {
1286         struct scsiback_tpg *tpg = container_of(se_tpg,
1287                                 struct scsiback_tpg, se_tpg);
1288         return tpg->tport_tpgt;
1289 }
1290
1291 static u32 scsiback_get_default_depth(struct se_portal_group *se_tpg)
1292 {
1293         return 1;
1294 }
1295
1296 static u32
1297 scsiback_get_pr_transport_id(struct se_portal_group *se_tpg,
1298                               struct se_node_acl *se_nacl,
1299                               struct t10_pr_registration *pr_reg,
1300                               int *format_code,
1301                               unsigned char *buf)
1302 {
1303         struct scsiback_tpg *tpg = container_of(se_tpg,
1304                                 struct scsiback_tpg, se_tpg);
1305         struct scsiback_tport *tport = tpg->tport;
1306
1307         switch (tport->tport_proto_id) {
1308         case SCSI_PROTOCOL_SAS:
1309                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1310                                         format_code, buf);
1311         case SCSI_PROTOCOL_FCP:
1312                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1313                                         format_code, buf);
1314         case SCSI_PROTOCOL_ISCSI:
1315                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1316                                         format_code, buf);
1317         default:
1318                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1319                         tport->tport_proto_id);
1320                 break;
1321         }
1322
1323         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1324                         format_code, buf);
1325 }
1326
1327 static u32
1328 scsiback_get_pr_transport_id_len(struct se_portal_group *se_tpg,
1329                                   struct se_node_acl *se_nacl,
1330                                   struct t10_pr_registration *pr_reg,
1331                                   int *format_code)
1332 {
1333         struct scsiback_tpg *tpg = container_of(se_tpg,
1334                                 struct scsiback_tpg, se_tpg);
1335         struct scsiback_tport *tport = tpg->tport;
1336
1337         switch (tport->tport_proto_id) {
1338         case SCSI_PROTOCOL_SAS:
1339                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1340                                         format_code);
1341         case SCSI_PROTOCOL_FCP:
1342                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1343                                         format_code);
1344         case SCSI_PROTOCOL_ISCSI:
1345                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1346                                         format_code);
1347         default:
1348                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1349                         tport->tport_proto_id);
1350                 break;
1351         }
1352
1353         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1354                         format_code);
1355 }
1356
1357 static char *
1358 scsiback_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
1359                                     const char *buf,
1360                                     u32 *out_tid_len,
1361                                     char **port_nexus_ptr)
1362 {
1363         struct scsiback_tpg *tpg = container_of(se_tpg,
1364                                 struct scsiback_tpg, se_tpg);
1365         struct scsiback_tport *tport = tpg->tport;
1366
1367         switch (tport->tport_proto_id) {
1368         case SCSI_PROTOCOL_SAS:
1369                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1370                                         port_nexus_ptr);
1371         case SCSI_PROTOCOL_FCP:
1372                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1373                                         port_nexus_ptr);
1374         case SCSI_PROTOCOL_ISCSI:
1375                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1376                                         port_nexus_ptr);
1377         default:
1378                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1379                         tport->tport_proto_id);
1380                 break;
1381         }
1382
1383         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1384                         port_nexus_ptr);
1385 }
1386
1387 static struct se_wwn *
1388 scsiback_make_tport(struct target_fabric_configfs *tf,
1389                      struct config_group *group,
1390                      const char *name)
1391 {
1392         struct scsiback_tport *tport;
1393         char *ptr;
1394         u64 wwpn = 0;
1395         int off = 0;
1396
1397         tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1398         if (!tport)
1399                 return ERR_PTR(-ENOMEM);
1400
1401         tport->tport_wwpn = wwpn;
1402         /*
1403          * Determine the emulated Protocol Identifier and Target Port Name
1404          * based on the incoming configfs directory name.
1405          */
1406         ptr = strstr(name, "naa.");
1407         if (ptr) {
1408                 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1409                 goto check_len;
1410         }
1411         ptr = strstr(name, "fc.");
1412         if (ptr) {
1413                 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1414                 off = 3; /* Skip over "fc." */
1415                 goto check_len;
1416         }
1417         ptr = strstr(name, "iqn.");
1418         if (ptr) {
1419                 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1420                 goto check_len;
1421         }
1422
1423         pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1424         kfree(tport);
1425         return ERR_PTR(-EINVAL);
1426
1427 check_len:
1428         if (strlen(name) >= VSCSI_NAMELEN) {
1429                 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1430                         scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1431                 kfree(tport);
1432                 return ERR_PTR(-EINVAL);
1433         }
1434         snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1435
1436         pr_debug("xen-pvscsi: Allocated emulated Target %s Address: %s\n",
1437                  scsiback_dump_proto_id(tport), name);
1438
1439         return &tport->tport_wwn;
1440 }
1441
1442 static void scsiback_drop_tport(struct se_wwn *wwn)
1443 {
1444         struct scsiback_tport *tport = container_of(wwn,
1445                                 struct scsiback_tport, tport_wwn);
1446
1447         pr_debug("xen-pvscsi: Deallocating emulated Target %s Address: %s\n",
1448                  scsiback_dump_proto_id(tport), tport->tport_name);
1449
1450         kfree(tport);
1451 }
1452
1453 static struct se_node_acl *
1454 scsiback_alloc_fabric_acl(struct se_portal_group *se_tpg)
1455 {
1456         return kzalloc(sizeof(struct se_node_acl), GFP_KERNEL);
1457 }
1458
1459 static void
1460 scsiback_release_fabric_acl(struct se_portal_group *se_tpg,
1461                              struct se_node_acl *se_nacl)
1462 {
1463         kfree(se_nacl);
1464 }
1465
1466 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1467 {
1468         return 1;
1469 }
1470
1471 static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1472 {
1473         /*
1474          * Do not release struct se_cmd's containing a valid TMR
1475          * pointer.  These will be released directly in scsiback_device_action()
1476          * with transport_generic_free_cmd().
1477          */
1478         if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1479                 return 0;
1480
1481         transport_generic_free_cmd(se_cmd, 0);
1482         return 1;
1483 }
1484
1485 static void scsiback_release_cmd(struct se_cmd *se_cmd)
1486 {
1487         struct vscsibk_pend *pending_req = container_of(se_cmd,
1488                                 struct vscsibk_pend, se_cmd);
1489
1490         kmem_cache_free(scsiback_cachep, pending_req);
1491 }
1492
1493 static int scsiback_shutdown_session(struct se_session *se_sess)
1494 {
1495         return 0;
1496 }
1497
1498 static void scsiback_close_session(struct se_session *se_sess)
1499 {
1500 }
1501
1502 static u32 scsiback_sess_get_index(struct se_session *se_sess)
1503 {
1504         return 0;
1505 }
1506
1507 static int scsiback_write_pending(struct se_cmd *se_cmd)
1508 {
1509         /* Go ahead and process the write immediately */
1510         target_execute_cmd(se_cmd);
1511
1512         return 0;
1513 }
1514
1515 static int scsiback_write_pending_status(struct se_cmd *se_cmd)
1516 {
1517         return 0;
1518 }
1519
1520 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1521 {
1522 }
1523
1524 static u32 scsiback_get_task_tag(struct se_cmd *se_cmd)
1525 {
1526         struct vscsibk_pend *pending_req = container_of(se_cmd,
1527                                 struct vscsibk_pend, se_cmd);
1528
1529         return pending_req->rqid;
1530 }
1531
1532 static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1533 {
1534         return 0;
1535 }
1536
1537 static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1538 {
1539         struct vscsibk_pend *pending_req = container_of(se_cmd,
1540                                 struct vscsibk_pend, se_cmd);
1541
1542         pending_req->result = SAM_STAT_GOOD;
1543         scsiback_cmd_done(pending_req);
1544         return 0;
1545 }
1546
1547 static int scsiback_queue_status(struct se_cmd *se_cmd)
1548 {
1549         struct vscsibk_pend *pending_req = container_of(se_cmd,
1550                                 struct vscsibk_pend, se_cmd);
1551
1552         if (se_cmd->sense_buffer &&
1553             ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1554              (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1555                 pending_req->result = (DRIVER_SENSE << 24) |
1556                                       SAM_STAT_CHECK_CONDITION;
1557         else
1558                 pending_req->result = se_cmd->scsi_status;
1559
1560         scsiback_cmd_done(pending_req);
1561         return 0;
1562 }
1563
1564 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1565 {
1566         struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
1567         struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr;
1568
1569         atomic_set(&tmr->tmr_complete, 1);
1570         wake_up(&tmr->tmr_wait);
1571 }
1572
1573 static void scsiback_aborted_task(struct se_cmd *se_cmd)
1574 {
1575 }
1576
1577 static ssize_t scsiback_tpg_param_show_alias(struct se_portal_group *se_tpg,
1578                                              char *page)
1579 {
1580         struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1581                                                 se_tpg);
1582         ssize_t rb;
1583
1584         mutex_lock(&tpg->tv_tpg_mutex);
1585         rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1586         mutex_unlock(&tpg->tv_tpg_mutex);
1587
1588         return rb;
1589 }
1590
1591 static ssize_t scsiback_tpg_param_store_alias(struct se_portal_group *se_tpg,
1592                                               const char *page, size_t count)
1593 {
1594         struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1595                                                 se_tpg);
1596         int len;
1597
1598         if (strlen(page) >= VSCSI_NAMELEN) {
1599                 pr_err("param alias: %s, exceeds max: %d\n", page,
1600                         VSCSI_NAMELEN);
1601                 return -EINVAL;
1602         }
1603
1604         mutex_lock(&tpg->tv_tpg_mutex);
1605         len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1606         if (tpg->param_alias[len - 1] == '\n')
1607                 tpg->param_alias[len - 1] = '\0';
1608         mutex_unlock(&tpg->tv_tpg_mutex);
1609
1610         return count;
1611 }
1612
1613 TF_TPG_PARAM_ATTR(scsiback, alias, S_IRUGO | S_IWUSR);
1614
1615 static struct configfs_attribute *scsiback_param_attrs[] = {
1616         &scsiback_tpg_param_alias.attr,
1617         NULL,
1618 };
1619
1620 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1621                                 const char *name)
1622 {
1623         struct se_portal_group *se_tpg;
1624         struct se_session *se_sess;
1625         struct scsiback_nexus *tv_nexus;
1626
1627         mutex_lock(&tpg->tv_tpg_mutex);
1628         if (tpg->tpg_nexus) {
1629                 mutex_unlock(&tpg->tv_tpg_mutex);
1630                 pr_debug("tpg->tpg_nexus already exists\n");
1631                 return -EEXIST;
1632         }
1633         se_tpg = &tpg->se_tpg;
1634
1635         tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1636         if (!tv_nexus) {
1637                 mutex_unlock(&tpg->tv_tpg_mutex);
1638                 return -ENOMEM;
1639         }
1640         /*
1641          *  Initialize the struct se_session pointer
1642          */
1643         tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_NORMAL);
1644         if (IS_ERR(tv_nexus->tvn_se_sess)) {
1645                 mutex_unlock(&tpg->tv_tpg_mutex);
1646                 kfree(tv_nexus);
1647                 return -ENOMEM;
1648         }
1649         se_sess = tv_nexus->tvn_se_sess;
1650         /*
1651          * Since we are running in 'demo mode' this call with generate a
1652          * struct se_node_acl for the scsiback struct se_portal_group with
1653          * the SCSI Initiator port name of the passed configfs group 'name'.
1654          */
1655         tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1656                                 se_tpg, (unsigned char *)name);
1657         if (!tv_nexus->tvn_se_sess->se_node_acl) {
1658                 mutex_unlock(&tpg->tv_tpg_mutex);
1659                 pr_debug("core_tpg_check_initiator_node_acl() failed for %s\n",
1660                          name);
1661                 goto out;
1662         }
1663         /*
1664          * Now register the TCM pvscsi virtual I_T Nexus as active with the
1665          * call to __transport_register_session()
1666          */
1667         __transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
1668                         tv_nexus->tvn_se_sess, tv_nexus);
1669         tpg->tpg_nexus = tv_nexus;
1670
1671         mutex_unlock(&tpg->tv_tpg_mutex);
1672         return 0;
1673
1674 out:
1675         transport_free_session(se_sess);
1676         kfree(tv_nexus);
1677         return -ENOMEM;
1678 }
1679
1680 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1681 {
1682         struct se_session *se_sess;
1683         struct scsiback_nexus *tv_nexus;
1684
1685         mutex_lock(&tpg->tv_tpg_mutex);
1686         tv_nexus = tpg->tpg_nexus;
1687         if (!tv_nexus) {
1688                 mutex_unlock(&tpg->tv_tpg_mutex);
1689                 return -ENODEV;
1690         }
1691
1692         se_sess = tv_nexus->tvn_se_sess;
1693         if (!se_sess) {
1694                 mutex_unlock(&tpg->tv_tpg_mutex);
1695                 return -ENODEV;
1696         }
1697
1698         if (tpg->tv_tpg_port_count != 0) {
1699                 mutex_unlock(&tpg->tv_tpg_mutex);
1700                 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1701                         tpg->tv_tpg_port_count);
1702                 return -EBUSY;
1703         }
1704
1705         if (tpg->tv_tpg_fe_count != 0) {
1706                 mutex_unlock(&tpg->tv_tpg_mutex);
1707                 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1708                         tpg->tv_tpg_fe_count);
1709                 return -EBUSY;
1710         }
1711
1712         pr_debug("xen-pvscsi: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1713                 scsiback_dump_proto_id(tpg->tport),
1714                 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1715
1716         /*
1717          * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1718          */
1719         transport_deregister_session(tv_nexus->tvn_se_sess);
1720         tpg->tpg_nexus = NULL;
1721         mutex_unlock(&tpg->tv_tpg_mutex);
1722
1723         kfree(tv_nexus);
1724         return 0;
1725 }
1726
1727 static ssize_t scsiback_tpg_show_nexus(struct se_portal_group *se_tpg,
1728                                         char *page)
1729 {
1730         struct scsiback_tpg *tpg = container_of(se_tpg,
1731                                 struct scsiback_tpg, se_tpg);
1732         struct scsiback_nexus *tv_nexus;
1733         ssize_t ret;
1734
1735         mutex_lock(&tpg->tv_tpg_mutex);
1736         tv_nexus = tpg->tpg_nexus;
1737         if (!tv_nexus) {
1738                 mutex_unlock(&tpg->tv_tpg_mutex);
1739                 return -ENODEV;
1740         }
1741         ret = snprintf(page, PAGE_SIZE, "%s\n",
1742                         tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1743         mutex_unlock(&tpg->tv_tpg_mutex);
1744
1745         return ret;
1746 }
1747
1748 static ssize_t scsiback_tpg_store_nexus(struct se_portal_group *se_tpg,
1749                                          const char *page,
1750                                          size_t count)
1751 {
1752         struct scsiback_tpg *tpg = container_of(se_tpg,
1753                                 struct scsiback_tpg, se_tpg);
1754         struct scsiback_tport *tport_wwn = tpg->tport;
1755         unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1756         int ret;
1757         /*
1758          * Shutdown the active I_T nexus if 'NULL' is passed..
1759          */
1760         if (!strncmp(page, "NULL", 4)) {
1761                 ret = scsiback_drop_nexus(tpg);
1762                 return (!ret) ? count : ret;
1763         }
1764         /*
1765          * Otherwise make sure the passed virtual Initiator port WWN matches
1766          * the fabric protocol_id set in scsiback_make_tport(), and call
1767          * scsiback_make_nexus().
1768          */
1769         if (strlen(page) >= VSCSI_NAMELEN) {
1770                 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1771                         page, VSCSI_NAMELEN);
1772                 return -EINVAL;
1773         }
1774         snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1775
1776         ptr = strstr(i_port, "naa.");
1777         if (ptr) {
1778                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1779                         pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1780                                 i_port, scsiback_dump_proto_id(tport_wwn));
1781                         return -EINVAL;
1782                 }
1783                 port_ptr = &i_port[0];
1784                 goto check_newline;
1785         }
1786         ptr = strstr(i_port, "fc.");
1787         if (ptr) {
1788                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1789                         pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1790                                 i_port, scsiback_dump_proto_id(tport_wwn));
1791                         return -EINVAL;
1792                 }
1793                 port_ptr = &i_port[3]; /* Skip over "fc." */
1794                 goto check_newline;
1795         }
1796         ptr = strstr(i_port, "iqn.");
1797         if (ptr) {
1798                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1799                         pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1800                                 i_port, scsiback_dump_proto_id(tport_wwn));
1801                         return -EINVAL;
1802                 }
1803                 port_ptr = &i_port[0];
1804                 goto check_newline;
1805         }
1806         pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1807                 i_port);
1808         return -EINVAL;
1809         /*
1810          * Clear any trailing newline for the NAA WWN
1811          */
1812 check_newline:
1813         if (i_port[strlen(i_port) - 1] == '\n')
1814                 i_port[strlen(i_port) - 1] = '\0';
1815
1816         ret = scsiback_make_nexus(tpg, port_ptr);
1817         if (ret < 0)
1818                 return ret;
1819
1820         return count;
1821 }
1822
1823 TF_TPG_BASE_ATTR(scsiback, nexus, S_IRUGO | S_IWUSR);
1824
1825 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1826         &scsiback_tpg_nexus.attr,
1827         NULL,
1828 };
1829
1830 static ssize_t
1831 scsiback_wwn_show_attr_version(struct target_fabric_configfs *tf,
1832                                 char *page)
1833 {
1834         return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1835                 UTS_RELEASE"\n",
1836                 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1837 }
1838
1839 TF_WWN_ATTR_RO(scsiback, version);
1840
1841 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1842         &scsiback_wwn_version.attr,
1843         NULL,
1844 };
1845
1846 static char *scsiback_get_fabric_name(void)
1847 {
1848         return "xen-pvscsi";
1849 }
1850
1851 static int scsiback_port_link(struct se_portal_group *se_tpg,
1852                                struct se_lun *lun)
1853 {
1854         struct scsiback_tpg *tpg = container_of(se_tpg,
1855                                 struct scsiback_tpg, se_tpg);
1856
1857         mutex_lock(&tpg->tv_tpg_mutex);
1858         tpg->tv_tpg_port_count++;
1859         mutex_unlock(&tpg->tv_tpg_mutex);
1860
1861         return 0;
1862 }
1863
1864 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1865                                   struct se_lun *lun)
1866 {
1867         struct scsiback_tpg *tpg = container_of(se_tpg,
1868                                 struct scsiback_tpg, se_tpg);
1869
1870         mutex_lock(&tpg->tv_tpg_mutex);
1871         tpg->tv_tpg_port_count--;
1872         mutex_unlock(&tpg->tv_tpg_mutex);
1873 }
1874
1875 static struct se_portal_group *
1876 scsiback_make_tpg(struct se_wwn *wwn,
1877                    struct config_group *group,
1878                    const char *name)
1879 {
1880         struct scsiback_tport *tport = container_of(wwn,
1881                         struct scsiback_tport, tport_wwn);
1882
1883         struct scsiback_tpg *tpg;
1884         u16 tpgt;
1885         int ret;
1886
1887         if (strstr(name, "tpgt_") != name)
1888                 return ERR_PTR(-EINVAL);
1889         ret = kstrtou16(name + 5, 10, &tpgt);
1890         if (ret)
1891                 return ERR_PTR(ret);
1892
1893         tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1894         if (!tpg)
1895                 return ERR_PTR(-ENOMEM);
1896
1897         mutex_init(&tpg->tv_tpg_mutex);
1898         INIT_LIST_HEAD(&tpg->tv_tpg_list);
1899         INIT_LIST_HEAD(&tpg->info_list);
1900         tpg->tport = tport;
1901         tpg->tport_tpgt = tpgt;
1902
1903         ret = core_tpg_register(&scsiback_fabric_configfs->tf_ops, wwn,
1904                                 &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
1905         if (ret < 0) {
1906                 kfree(tpg);
1907                 return NULL;
1908         }
1909         mutex_lock(&scsiback_mutex);
1910         list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1911         mutex_unlock(&scsiback_mutex);
1912
1913         return &tpg->se_tpg;
1914 }
1915
1916 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1917 {
1918         struct scsiback_tpg *tpg = container_of(se_tpg,
1919                                 struct scsiback_tpg, se_tpg);
1920
1921         mutex_lock(&scsiback_mutex);
1922         list_del(&tpg->tv_tpg_list);
1923         mutex_unlock(&scsiback_mutex);
1924         /*
1925          * Release the virtual I_T Nexus for this xen-pvscsi TPG
1926          */
1927         scsiback_drop_nexus(tpg);
1928         /*
1929          * Deregister the se_tpg from TCM..
1930          */
1931         core_tpg_deregister(se_tpg);
1932         kfree(tpg);
1933 }
1934
1935 static int scsiback_check_true(struct se_portal_group *se_tpg)
1936 {
1937         return 1;
1938 }
1939
1940 static int scsiback_check_false(struct se_portal_group *se_tpg)
1941 {
1942         return 0;
1943 }
1944
1945 static struct target_core_fabric_ops scsiback_ops = {
1946         .get_fabric_name                = scsiback_get_fabric_name,
1947         .get_fabric_proto_ident         = scsiback_get_fabric_proto_ident,
1948         .tpg_get_wwn                    = scsiback_get_fabric_wwn,
1949         .tpg_get_tag                    = scsiback_get_tag,
1950         .tpg_get_default_depth          = scsiback_get_default_depth,
1951         .tpg_get_pr_transport_id        = scsiback_get_pr_transport_id,
1952         .tpg_get_pr_transport_id_len    = scsiback_get_pr_transport_id_len,
1953         .tpg_parse_pr_out_transport_id  = scsiback_parse_pr_out_transport_id,
1954         .tpg_check_demo_mode            = scsiback_check_true,
1955         .tpg_check_demo_mode_cache      = scsiback_check_true,
1956         .tpg_check_demo_mode_write_protect = scsiback_check_false,
1957         .tpg_check_prod_mode_write_protect = scsiback_check_false,
1958         .tpg_alloc_fabric_acl           = scsiback_alloc_fabric_acl,
1959         .tpg_release_fabric_acl         = scsiback_release_fabric_acl,
1960         .tpg_get_inst_index             = scsiback_tpg_get_inst_index,
1961         .check_stop_free                = scsiback_check_stop_free,
1962         .release_cmd                    = scsiback_release_cmd,
1963         .put_session                    = NULL,
1964         .shutdown_session               = scsiback_shutdown_session,
1965         .close_session                  = scsiback_close_session,
1966         .sess_get_index                 = scsiback_sess_get_index,
1967         .sess_get_initiator_sid         = NULL,
1968         .write_pending                  = scsiback_write_pending,
1969         .write_pending_status           = scsiback_write_pending_status,
1970         .set_default_node_attributes    = scsiback_set_default_node_attrs,
1971         .get_task_tag                   = scsiback_get_task_tag,
1972         .get_cmd_state                  = scsiback_get_cmd_state,
1973         .queue_data_in                  = scsiback_queue_data_in,
1974         .queue_status                   = scsiback_queue_status,
1975         .queue_tm_rsp                   = scsiback_queue_tm_rsp,
1976         .aborted_task                   = scsiback_aborted_task,
1977         /*
1978          * Setup callers for generic logic in target_core_fabric_configfs.c
1979          */
1980         .fabric_make_wwn                = scsiback_make_tport,
1981         .fabric_drop_wwn                = scsiback_drop_tport,
1982         .fabric_make_tpg                = scsiback_make_tpg,
1983         .fabric_drop_tpg                = scsiback_drop_tpg,
1984         .fabric_post_link               = scsiback_port_link,
1985         .fabric_pre_unlink              = scsiback_port_unlink,
1986         .fabric_make_np                 = NULL,
1987         .fabric_drop_np                 = NULL,
1988 #if 0
1989         .fabric_make_nodeacl            = scsiback_make_nodeacl,
1990         .fabric_drop_nodeacl            = scsiback_drop_nodeacl,
1991 #endif
1992 };
1993
1994 static int scsiback_register_configfs(void)
1995 {
1996         struct target_fabric_configfs *fabric;
1997         int ret;
1998
1999         pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
2000                  VSCSI_VERSION, utsname()->sysname, utsname()->machine);
2001         /*
2002          * Register the top level struct config_item_type with TCM core
2003          */
2004         fabric = target_fabric_configfs_init(THIS_MODULE, "xen-pvscsi");
2005         if (IS_ERR(fabric))
2006                 return PTR_ERR(fabric);
2007
2008         /*
2009          * Setup fabric->tf_ops from our local scsiback_ops
2010          */
2011         fabric->tf_ops = scsiback_ops;
2012         /*
2013          * Setup default attribute lists for various fabric->tf_cit_tmpl
2014          */
2015         fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = scsiback_wwn_attrs;
2016         fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = scsiback_tpg_attrs;
2017         fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
2018         fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = scsiback_param_attrs;
2019         fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
2020         fabric->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
2021         fabric->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
2022         fabric->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
2023         fabric->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
2024         /*
2025          * Register the fabric for use within TCM
2026          */
2027         ret = target_fabric_configfs_register(fabric);
2028         if (ret < 0) {
2029                 target_fabric_configfs_free(fabric);
2030                 return ret;
2031         }
2032         /*
2033          * Setup our local pointer to *fabric
2034          */
2035         scsiback_fabric_configfs = fabric;
2036         pr_debug("xen-pvscsi: Set fabric -> scsiback_fabric_configfs\n");
2037         return 0;
2038 };
2039
2040 static void scsiback_deregister_configfs(void)
2041 {
2042         if (!scsiback_fabric_configfs)
2043                 return;
2044
2045         target_fabric_configfs_deregister(scsiback_fabric_configfs);
2046         scsiback_fabric_configfs = NULL;
2047         pr_debug("xen-pvscsi: Cleared scsiback_fabric_configfs\n");
2048 };
2049
2050 static const struct xenbus_device_id scsiback_ids[] = {
2051         { "vscsi" },
2052         { "" }
2053 };
2054
2055 static struct xenbus_driver scsiback_driver = {
2056         .ids                    = scsiback_ids,
2057         .probe                  = scsiback_probe,
2058         .remove                 = scsiback_remove,
2059         .otherend_changed       = scsiback_frontend_changed
2060 };
2061
2062 static void scsiback_init_pend(void *p)
2063 {
2064         struct vscsibk_pend *pend = p;
2065         int i;
2066
2067         memset(pend, 0, sizeof(*pend));
2068         for (i = 0; i < VSCSI_MAX_GRANTS; i++)
2069                 pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
2070 }
2071
2072 static int __init scsiback_init(void)
2073 {
2074         int ret;
2075
2076         if (!xen_domain())
2077                 return -ENODEV;
2078
2079         scsiback_cachep = kmem_cache_create("vscsiif_cache",
2080                 sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
2081         if (!scsiback_cachep)
2082                 return -ENOMEM;
2083
2084         ret = xenbus_register_backend(&scsiback_driver);
2085         if (ret)
2086                 goto out_cache_destroy;
2087
2088         ret = scsiback_register_configfs();
2089         if (ret)
2090                 goto out_unregister_xenbus;
2091
2092         return 0;
2093
2094 out_unregister_xenbus:
2095         xenbus_unregister_driver(&scsiback_driver);
2096 out_cache_destroy:
2097         kmem_cache_destroy(scsiback_cachep);
2098         pr_err("xen-pvscsi: %s: error %d\n", __func__, ret);
2099         return ret;
2100 }
2101
2102 static void __exit scsiback_exit(void)
2103 {
2104         struct page *page;
2105
2106         while (free_pages_num) {
2107                 if (get_free_page(&page))
2108                         BUG();
2109                 gnttab_free_pages(1, &page);
2110         }
2111         scsiback_deregister_configfs();
2112         xenbus_unregister_driver(&scsiback_driver);
2113         kmem_cache_destroy(scsiback_cachep);
2114 }
2115
2116 module_init(scsiback_init);
2117 module_exit(scsiback_exit);
2118
2119 MODULE_DESCRIPTION("Xen SCSI backend driver");
2120 MODULE_LICENSE("Dual BSD/GPL");
2121 MODULE_ALIAS("xen-backend:vscsi");
2122 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");