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.h>
  51 #include <scsi/scsi_dbg.h>
  52 #include <scsi/scsi_eh.h>
  53 #include <scsi/scsi_tcq.h>
  54
  55 #include <target/target_core_base.h>
  56 #include <target/target_core_fabric.h>
  57 #include <target/target_core_configfs.h>
  58 #include <target/target_core_fabric_configfs.h>
  59
  60 #include <asm/hypervisor.h>
  61
  62 #include <xen/xen.h>
  63 #include <xen/balloon.h>
  64 #include <xen/events.h>
  65 #include <xen/xenbus.h>
  66 #include <xen/grant_table.h>
  67 #include <xen/page.h>
  68
  69 #include <xen/interface/grant_table.h>
  70 #include <xen/interface/io/vscsiif.h>
  71
  72 #define DPRINTK(_f, _a...)                      \
  73         pr_debug("(file=%s, line=%d) " _f, __FILE__ , __LINE__ , ## _a)
  74
  75 #define VSCSI_VERSION   "v0.1"
  76 #define VSCSI_NAMELEN   32
  77
  78 struct ids_tuple {
  79         unsigned int hst;               /* host    */
  80         unsigned int chn;               /* channel */
  81         unsigned int tgt;               /* target  */
  82         unsigned int lun;               /* LUN     */
  83 };
  84
  85 struct v2p_entry {
  86         struct ids_tuple v;             /* translate from */
  87         struct scsiback_tpg *tpg;       /* translate to   */
  88         unsigned int lun;
  89         struct kref kref;
  90         struct list_head l;
  91 };
  92
  93 struct vscsibk_info {
  94         struct xenbus_device *dev;
  95
  96         domid_t domid;
  97         unsigned int irq;
  98
  99         struct vscsiif_back_ring ring;
 100         int ring_error;
 101
 102         spinlock_t ring_lock;
 103         atomic_t nr_unreplied_reqs;
 104
 105         spinlock_t v2p_lock;
 106         struct list_head v2p_entry_lists;
 107
 108         wait_queue_head_t waiting_to_free;
 109 };
 110
 111 /* theoretical maximum of grants for one request */
 112 #define VSCSI_MAX_GRANTS        (SG_ALL + VSCSIIF_SG_TABLESIZE)
 113
 114 /*
 115  * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
 116  * call to map/unmap grants. Don't choose it too large, as there are arrays
 117  * with VSCSI_GRANT_BATCH elements allocated on the stack.
 118  */
 119 #define VSCSI_GRANT_BATCH       16
 120
 121 struct vscsibk_pend {
 122         uint16_t rqid;
 123
 124         uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
 125         uint8_t cmd_len;
 126
 127         uint8_t sc_data_direction;
 128         uint16_t n_sg;          /* real length of SG list */
 129         uint16_t n_grants;      /* SG pages and potentially SG list */
 130         uint32_t data_len;
 131         uint32_t result;
 132
 133         struct vscsibk_info *info;
 134         struct v2p_entry *v2p;
 135         struct scatterlist *sgl;
 136
 137         uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
 138
 139         grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
 140         struct page *pages[VSCSI_MAX_GRANTS];
 141
 142         struct se_cmd se_cmd;
 143 };
 144
 145 struct scsiback_tmr {
 146         atomic_t tmr_complete;
 147         wait_queue_head_t tmr_wait;
 148 };
 149
 150 struct scsiback_nexus {
 151         /* Pointer to TCM session for I_T Nexus */
 152         struct se_session *tvn_se_sess;
 153 };
 154
 155 struct scsiback_tport {
 156         /* SCSI protocol the tport is providing */
 157         u8 tport_proto_id;
 158         /* Binary World Wide unique Port Name for pvscsi Target port */
 159         u64 tport_wwpn;
 160         /* ASCII formatted WWPN for pvscsi Target port */
 161         char tport_name[VSCSI_NAMELEN];
 162         /* Returned by scsiback_make_tport() */
 163         struct se_wwn tport_wwn;
 164 };
 165
 166 struct scsiback_tpg {
 167         /* scsiback port target portal group tag for TCM */
 168         u16 tport_tpgt;
 169         /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
 170         int tv_tpg_port_count;
 171         /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
 172         int tv_tpg_fe_count;
 173         /* list for scsiback_list */
 174         struct list_head tv_tpg_list;
 175         /* Used to protect access for tpg_nexus */
 176         struct mutex tv_tpg_mutex;
 177         /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
 178         struct scsiback_nexus *tpg_nexus;
 179         /* Pointer back to scsiback_tport */
 180         struct scsiback_tport *tport;
 181         /* Returned by scsiback_make_tpg() */
 182         struct se_portal_group se_tpg;
 183         /* alias used in xenstore */
 184         char param_alias[VSCSI_NAMELEN];
 185         /* list of info structures related to this target portal group */
 186         struct list_head info_list;
 187 };
 188
 189 #define SCSIBACK_INVALID_HANDLE (~0)
 190
 191 static bool log_print_stat;
 192 module_param(log_print_stat, bool, 0644);
 193
 194 static int scsiback_max_buffer_pages = 1024;
 195 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
 196 MODULE_PARM_DESC(max_buffer_pages,
 197 "Maximum number of free pages to keep in backend buffer");
 198
 199 static struct kmem_cache *scsiback_cachep;
 200 static DEFINE_SPINLOCK(free_pages_lock);
 201 static int free_pages_num;
 202 static LIST_HEAD(scsiback_free_pages);
 203
 204 /* Global spinlock to protect scsiback TPG list */
 205 static DEFINE_MUTEX(scsiback_mutex);
 206 static LIST_HEAD(scsiback_list);
 207
 208 /* Local pointer to allocated TCM configfs fabric module */
 209 static struct target_fabric_configfs *scsiback_fabric_configfs;
 210
 211 static void scsiback_get(struct vscsibk_info *info)
 212 {
 213         atomic_inc(&info->nr_unreplied_reqs);
 214 }
 215
 216 static void scsiback_put(struct vscsibk_info *info)
 217 {
 218         if (atomic_dec_and_test(&info->nr_unreplied_reqs))
 219                 wake_up(&info->waiting_to_free);
 220 }
 221
 222 static void put_free_pages(struct page **page, int num)
 223 {
 224         unsigned long flags;
 225         int i = free_pages_num + num, n = num;
 226
 227         if (num == 0)
 228                 return;
 229         if (i > scsiback_max_buffer_pages) {
 230                 n = min(num, i - scsiback_max_buffer_pages);
 231                 gnttab_free_pages(n, page + num - n);
 232                 n = num - n;
 233         }
 234         spin_lock_irqsave(&free_pages_lock, flags);
 235         for (i = 0; i < n; i++)
 236                 list_add(&page[i]->lru, &scsiback_free_pages);
 237         free_pages_num += n;
 238         spin_unlock_irqrestore(&free_pages_lock, flags);
 239 }
 240
 241 static int get_free_page(struct page **page)
 242 {
 243         unsigned long flags;
 244
 245         spin_lock_irqsave(&free_pages_lock, flags);
 246         if (list_empty(&scsiback_free_pages)) {
 247                 spin_unlock_irqrestore(&free_pages_lock, flags);
 248                 return gnttab_alloc_pages(1, page);
 249         }
 250         page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
 251         list_del(&page[0]->lru);
 252         free_pages_num--;
 253         spin_unlock_irqrestore(&free_pages_lock, flags);
 254         return 0;
 255 }
 256
 257 static unsigned long vaddr_page(struct page *page)
 258 {
 259         unsigned long pfn = page_to_pfn(page);
 260
 261         return (unsigned long)pfn_to_kaddr(pfn);
 262 }
 263
 264 static unsigned long vaddr(struct vscsibk_pend *req, int seg)
 265 {
 266         return vaddr_page(req->pages[seg]);
 267 }
 268
 269 static void scsiback_print_status(char *sense_buffer, int errors,
 270                                         struct vscsibk_pend *pending_req)
 271 {
 272         struct scsiback_tpg *tpg = pending_req->v2p->tpg;
 273
 274         pr_err("xen-pvscsi[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n",
 275                tpg->tport->tport_name, pending_req->v2p->lun,
 276                pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
 277                host_byte(errors), driver_byte(errors));
 278 }
 279
 280 static void scsiback_fast_flush_area(struct vscsibk_pend *req)
 281 {
 282         struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
 283         struct page *pages[VSCSI_GRANT_BATCH];
 284         unsigned int i, invcount = 0;
 285         grant_handle_t handle;
 286         int err;
 287
 288         kfree(req->sgl);
 289         req->sgl = NULL;
 290         req->n_sg = 0;
 291
 292         if (!req->n_grants)
 293                 return;
 294
 295         for (i = 0; i < req->n_grants; i++) {
 296                 handle = req->grant_handles[i];
 297                 if (handle == SCSIBACK_INVALID_HANDLE)
 298                         continue;
 299                 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
 300                                     GNTMAP_host_map, handle);
 301                 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
 302                 pages[invcount] = req->pages[i];
 303                 put_page(pages[invcount]);
 304                 invcount++;
 305                 if (invcount < VSCSI_GRANT_BATCH)
 306                         continue;
 307                 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
 308                 BUG_ON(err);
 309                 invcount = 0;
 310         }
 311
 312         if (invcount) {
 313                 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
 314                 BUG_ON(err);
 315         }
 316
 317         put_free_pages(req->pages, req->n_grants);
 318         req->n_grants = 0;
 319 }
 320
 321 static void scsiback_free_translation_entry(struct kref *kref)
 322 {
 323         struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
 324         struct scsiback_tpg *tpg = entry->tpg;
 325
 326         mutex_lock(&tpg->tv_tpg_mutex);
 327         tpg->tv_tpg_fe_count--;
 328         mutex_unlock(&tpg->tv_tpg_mutex);
 329
 330         kfree(entry);
 331 }
 332
 333 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
 334                         uint32_t resid, struct vscsibk_pend *pending_req)
 335 {
 336         struct vscsiif_response *ring_res;
 337         struct vscsibk_info *info = pending_req->info;
 338         int notify;
 339         struct scsi_sense_hdr sshdr;
 340         unsigned long flags;
 341         unsigned len;
 342
 343         spin_lock_irqsave(&info->ring_lock, flags);
 344
 345         ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
 346         info->ring.rsp_prod_pvt++;
 347
 348         ring_res->rslt   = result;
 349         ring_res->rqid   = pending_req->rqid;
 350
 351         if (sense_buffer != NULL &&
 352             scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
 353                                  &sshdr)) {
 354                 len = min_t(unsigned, 8 + sense_buffer[7],
 355                             VSCSIIF_SENSE_BUFFERSIZE);
 356                 memcpy(ring_res->sense_buffer, sense_buffer, len);
 357                 ring_res->sense_len = len;
 358         } else {
 359                 ring_res->sense_len = 0;
 360         }
 361
 362         ring_res->residual_len = resid;
 363
 364         RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
 365         spin_unlock_irqrestore(&info->ring_lock, flags);
 366
 367         if (notify)
 368                 notify_remote_via_irq(info->irq);
 369
 370         if (pending_req->v2p)
 371                 kref_put(&pending_req->v2p->kref,
 372                          scsiback_free_translation_entry);
 373 }
 374
 375 static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
 376 {
 377         struct vscsibk_info *info = pending_req->info;
 378         unsigned char *sense_buffer;
 379         unsigned int resid;
 380         int errors;
 381
 382         sense_buffer = pending_req->sense_buffer;
 383         resid        = pending_req->se_cmd.residual_count;
 384         errors       = pending_req->result;
 385
 386         if (errors && log_print_stat)
 387                 scsiback_print_status(sense_buffer, errors, pending_req);
 388
 389         scsiback_fast_flush_area(pending_req);
 390         scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
 391         scsiback_put(info);
 392 }
 393
 394 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
 395 {
 396         struct se_cmd *se_cmd = &pending_req->se_cmd;
 397         struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
 398         int rc;
 399
 400         memset(pending_req->sense_buffer, 0, VSCSIIF_SENSE_BUFFERSIZE);
 401
 402         memset(se_cmd, 0, sizeof(*se_cmd));
 403
 404         scsiback_get(pending_req->info);
 405         rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
 406                         pending_req->sense_buffer, pending_req->v2p->lun,
 407                         pending_req->data_len, 0,
 408                         pending_req->sc_data_direction, 0,
 409                         pending_req->sgl, pending_req->n_sg,
 410                         NULL, 0, NULL, 0);
 411         if (rc < 0) {
 412                 transport_send_check_condition_and_sense(se_cmd,
 413                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 414                 transport_generic_free_cmd(se_cmd, 0);
 415         }
 416 }
 417
 418 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
 419         struct page **pg, grant_handle_t *grant, int cnt)
 420 {
 421         int err, i;
 422
 423         if (!cnt)
 424                 return 0;
 425
 426         err = gnttab_map_refs(map, NULL, pg, cnt);
 427         BUG_ON(err);
 428         for (i = 0; i < cnt; i++) {
 429                 if (unlikely(map[i].status != GNTST_okay)) {
 430                         pr_err("xen-pvscsi: invalid buffer -- could not remap it\n");
 431                         map[i].handle = SCSIBACK_INVALID_HANDLE;
 432                         err = -ENOMEM;
 433                 } else {
 434                         get_page(pg[i]);
 435                 }
 436                 grant[i] = map[i].handle;
 437         }
 438         return err;
 439 }
 440
 441 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
 442                         struct scsiif_request_segment *seg, struct page **pg,
 443                         grant_handle_t *grant, int cnt, u32 flags)
 444 {
 445         int mapcount = 0, i, err = 0;
 446         struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
 447         struct vscsibk_info *info = pending_req->info;
 448
 449         for (i = 0; i < cnt; i++) {
 450                 if (get_free_page(pg + mapcount)) {
 451                         put_free_pages(pg, mapcount);
 452                         pr_err("xen-pvscsi: no grant page\n");
 453                         return -ENOMEM;
 454                 }
 455                 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
 456                                   flags, seg[i].gref, info->domid);
 457                 mapcount++;
 458                 if (mapcount < VSCSI_GRANT_BATCH)
 459                         continue;
 460                 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
 461                 pg += mapcount;
 462                 grant += mapcount;
 463                 pending_req->n_grants += mapcount;
 464                 if (err)
 465                         return err;
 466                 mapcount = 0;
 467         }
 468         err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
 469         pending_req->n_grants += mapcount;
 470         return err;
 471 }
 472
 473 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
 474                                         struct vscsibk_pend *pending_req)
 475 {
 476         u32 flags;
 477         int i, err, n_segs, i_seg = 0;
 478         struct page **pg;
 479         struct scsiif_request_segment *seg;
 480         unsigned long end_seg = 0;
 481         unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
 482         unsigned int nr_sgl = 0;
 483         struct scatterlist *sg;
 484         grant_handle_t *grant;
 485
 486         pending_req->n_sg = 0;
 487         pending_req->n_grants = 0;
 488         pending_req->data_len = 0;
 489
 490         nr_segments &= ~VSCSIIF_SG_GRANT;
 491         if (!nr_segments)
 492                 return 0;
 493
 494         if (nr_segments > VSCSIIF_SG_TABLESIZE) {
 495                 DPRINTK("xen-pvscsi: invalid parameter nr_seg = %d\n",
 496                         ring_req->nr_segments);
 497                 return -EINVAL;
 498         }
 499
 500         if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
 501                 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
 502                         pending_req->pages, pending_req->grant_handles,
 503                         nr_segments, GNTMAP_host_map | GNTMAP_readonly);
 504                 if (err)
 505                         return err;
 506                 nr_sgl = nr_segments;
 507                 nr_segments = 0;
 508                 for (i = 0; i < nr_sgl; i++) {
 509                         n_segs = ring_req->seg[i].length /
 510                                  sizeof(struct scsiif_request_segment);
 511                         if ((unsigned)ring_req->seg[i].offset +
 512                             (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
 513                             n_segs * sizeof(struct scsiif_request_segment) !=
 514                             ring_req->seg[i].length)
 515                                 return -EINVAL;
 516                         nr_segments += n_segs;
 517                 }
 518                 if (nr_segments > SG_ALL) {
 519                         DPRINTK("xen-pvscsi: invalid nr_seg = %d\n",
 520                                 nr_segments);
 521                         return -EINVAL;
 522                 }
 523         }
 524
 525         /* free of (sgl) in fast_flush_area()*/
 526         pending_req->sgl = kmalloc_array(nr_segments,
 527                                         sizeof(struct scatterlist), GFP_KERNEL);
 528         if (!pending_req->sgl)
 529                 return -ENOMEM;
 530
 531         sg_init_table(pending_req->sgl, nr_segments);
 532         pending_req->n_sg = nr_segments;
 533
 534         flags = GNTMAP_host_map;
 535         if (pending_req->sc_data_direction == DMA_TO_DEVICE)
 536                 flags |= GNTMAP_readonly;
 537
 538         pg = pending_req->pages + nr_sgl;
 539         grant = pending_req->grant_handles + nr_sgl;
 540         if (!nr_sgl) {
 541                 seg = ring_req->seg;
 542                 err = scsiback_gnttab_data_map_list(pending_req, seg,
 543                         pg, grant, nr_segments, flags);
 544                 if (err)
 545                         return err;
 546         } else {
 547                 for (i = 0; i < nr_sgl; i++) {
 548                         seg = (struct scsiif_request_segment *)(
 549                               vaddr(pending_req, i) + ring_req->seg[i].offset);
 550                         n_segs = ring_req->seg[i].length /
 551                                  sizeof(struct scsiif_request_segment);
 552                         err = scsiback_gnttab_data_map_list(pending_req, seg,
 553                                 pg, grant, n_segs, flags);
 554                         if (err)
 555                                 return err;
 556                         pg += n_segs;
 557                         grant += n_segs;
 558                 }
 559                 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
 560                 seg = (struct scsiif_request_segment *)end_seg;
 561                 end_seg += ring_req->seg[0].length;
 562                 pg = pending_req->pages + nr_sgl;
 563         }
 564
 565         for_each_sg(pending_req->sgl, sg, nr_segments, i) {
 566                 sg_set_page(sg, pg[i], seg->length, seg->offset);
 567                 pending_req->data_len += seg->length;
 568                 seg++;
 569                 if (nr_sgl && (unsigned long)seg >= end_seg) {
 570                         i_seg++;
 571                         end_seg = vaddr(pending_req, i_seg) +
 572                                   ring_req->seg[i_seg].offset;
 573                         seg = (struct scsiif_request_segment *)end_seg;
 574                         end_seg += ring_req->seg[i_seg].length;
 575                 }
 576                 if (sg->offset >= PAGE_SIZE ||
 577                     sg->length > PAGE_SIZE ||
 578                     sg->offset + sg->length > PAGE_SIZE)
 579                         return -EINVAL;
 580         }
 581
 582         return 0;
 583 }
 584
 585 static void scsiback_disconnect(struct vscsibk_info *info)
 586 {
 587         wait_event(info->waiting_to_free,
 588                 atomic_read(&info->nr_unreplied_reqs) == 0);
 589
 590         unbind_from_irqhandler(info->irq, info);
 591         info->irq = 0;
 592         xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
 593 }
 594
 595 static void scsiback_device_action(struct vscsibk_pend *pending_req,
 596         enum tcm_tmreq_table act, int tag)
 597 {
 598         int rc, err = FAILED;
 599         struct scsiback_tpg *tpg = pending_req->v2p->tpg;
 600         struct se_cmd *se_cmd = &pending_req->se_cmd;
 601         struct scsiback_tmr *tmr;
 602
 603         tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
 604         if (!tmr)
 605                 goto out;
 606
 607         init_waitqueue_head(&tmr->tmr_wait);
 608
 609         transport_init_se_cmd(se_cmd, tpg->se_tpg.se_tpg_tfo,
 610                 tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, TCM_SIMPLE_TAG,
 611                 &pending_req->sense_buffer[0]);
 612
 613         rc = core_tmr_alloc_req(se_cmd, tmr, act, GFP_KERNEL);
 614         if (rc < 0)
 615                 goto out;
 616
 617         se_cmd->se_tmr_req->ref_task_tag = tag;
 618
 619         if (transport_lookup_tmr_lun(se_cmd, pending_req->v2p->lun) < 0)
 620                 goto out;
 621
 622         transport_generic_handle_tmr(se_cmd);
 623         wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
 624
 625         err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
 626                 SUCCESS : FAILED;
 627
 628 out:
 629         if (tmr) {
 630                 transport_generic_free_cmd(&pending_req->se_cmd, 1);
 631                 kfree(tmr);
 632         }
 633
 634         scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
 635
 636         kmem_cache_free(scsiback_cachep, pending_req);
 637 }
 638
 639 /*
 640   Perform virtual to physical translation
 641 */
 642 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
 643                         struct ids_tuple *v)
 644 {
 645         struct v2p_entry *entry;
 646         struct list_head *head = &(info->v2p_entry_lists);
 647         unsigned long flags;
 648
 649         spin_lock_irqsave(&info->v2p_lock, flags);
 650         list_for_each_entry(entry, head, l) {
 651                 if ((entry->v.chn == v->chn) &&
 652                     (entry->v.tgt == v->tgt) &&
 653                     (entry->v.lun == v->lun)) {
 654                         kref_get(&entry->kref);
 655                         goto out;
 656                 }
 657         }
 658         entry = NULL;
 659
 660 out:
 661         spin_unlock_irqrestore(&info->v2p_lock, flags);
 662         return entry;
 663 }
 664
 665 static int prepare_pending_reqs(struct vscsibk_info *info,
 666                                 struct vscsiif_request *ring_req,
 667                                 struct vscsibk_pend *pending_req)
 668 {
 669         struct v2p_entry *v2p;
 670         struct ids_tuple vir;
 671
 672         pending_req->rqid       = ring_req->rqid;
 673         pending_req->info       = info;
 674
 675         vir.chn = ring_req->channel;
 676         vir.tgt = ring_req->id;
 677         vir.lun = ring_req->lun;
 678
 679         v2p = scsiback_do_translation(info, &vir);
 680         if (!v2p) {
 681                 pending_req->v2p = NULL;
 682                 DPRINTK("xen-pvscsi: doesn't exist.\n");
 683                 return -ENODEV;
 684         }
 685         pending_req->v2p = v2p;
 686
 687         /* request range check from frontend */
 688         pending_req->sc_data_direction = ring_req->sc_data_direction;
 689         if ((pending_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
 690                 (pending_req->sc_data_direction != DMA_TO_DEVICE) &&
 691                 (pending_req->sc_data_direction != DMA_FROM_DEVICE) &&
 692                 (pending_req->sc_data_direction != DMA_NONE)) {
 693                 DPRINTK("xen-pvscsi: invalid parameter data_dir = %d\n",
 694                         pending_req->sc_data_direction);
 695                 return -EINVAL;
 696         }
 697
 698         pending_req->cmd_len = ring_req->cmd_len;
 699         if (pending_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
 700                 DPRINTK("xen-pvscsi: invalid parameter cmd_len = %d\n",
 701                         pending_req->cmd_len);
 702                 return -EINVAL;
 703         }
 704         memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
 705
 706         return 0;
 707 }
 708
 709 static int scsiback_do_cmd_fn(struct vscsibk_info *info)
 710 {
 711         struct vscsiif_back_ring *ring = &info->ring;
 712         struct vscsiif_request ring_req;
 713         struct vscsibk_pend *pending_req;
 714         RING_IDX rc, rp;
 715         int err, more_to_do;
 716         uint32_t result;
 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                 err = prepare_pending_reqs(info, &ring_req, pending_req);
 741                 if (err) {
 742                         switch (err) {
 743                         case -ENODEV:
 744                                 result = DID_NO_CONNECT;
 745                                 break;
 746                         default:
 747                                 result = DRIVER_ERROR;
 748                                 break;
 749                         }
 750                         scsiback_do_resp_with_sense(NULL, result << 24, 0,
 751                                                     pending_req);
 752                         kmem_cache_free(scsiback_cachep, pending_req);
 753                         return 1;
 754                 }
 755
 756                 switch (ring_req.act) {
 757                 case VSCSIIF_ACT_SCSI_CDB:
 758                         if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
 759                                 scsiback_fast_flush_area(pending_req);
 760                                 scsiback_do_resp_with_sense(NULL,
 761                                         DRIVER_ERROR << 24, 0, pending_req);
 762                                 kmem_cache_free(scsiback_cachep, pending_req);
 763                         } else {
 764                                 scsiback_cmd_exec(pending_req);
 765                         }
 766                         break;
 767                 case VSCSIIF_ACT_SCSI_ABORT:
 768                         scsiback_device_action(pending_req, TMR_ABORT_TASK,
 769                                 ring_req.ref_rqid);
 770                         break;
 771                 case VSCSIIF_ACT_SCSI_RESET:
 772                         scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
 773                         break;
 774                 default:
 775                         pr_err_ratelimited("xen-pvscsi: invalid request\n");
 776                         scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24,
 777                                                     0, pending_req);
 778                         kmem_cache_free(scsiback_cachep, pending_req);
 779                         break;
 780                 }
 781
 782                 /* Yield point for this unbounded loop. */
 783                 cond_resched();
 784         }
 785
 786         RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
 787         return more_to_do;
 788 }
 789
 790 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
 791 {
 792         struct vscsibk_info *info = dev_id;
 793
 794         if (info->ring_error)
 795                 return IRQ_HANDLED;
 796
 797         while (scsiback_do_cmd_fn(info))
 798                 cond_resched();
 799
 800         return IRQ_HANDLED;
 801 }
 802
 803 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
 804                         evtchn_port_t evtchn)
 805 {
 806         void *area;
 807         struct vscsiif_sring *sring;
 808         int err;
 809
 810         if (info->irq)
 811                 return -1;
 812
 813         err = xenbus_map_ring_valloc(info->dev, ring_ref, &area);
 814         if (err)
 815                 return err;
 816
 817         sring = (struct vscsiif_sring *)area;
 818         BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
 819
 820         err = bind_interdomain_evtchn_to_irq(info->domid, evtchn);
 821         if (err < 0)
 822                 goto unmap_page;
 823
 824         info->irq = err;
 825
 826         err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
 827                                    IRQF_ONESHOT, "vscsiif-backend", info);
 828         if (err)
 829                 goto free_irq;
 830
 831         return 0;
 832
 833 free_irq:
 834         unbind_from_irqhandler(info->irq, info);
 835         info->irq = 0;
 836 unmap_page:
 837         xenbus_unmap_ring_vfree(info->dev, area);
 838
 839         return err;
 840 }
 841
 842 static int scsiback_map(struct vscsibk_info *info)
 843 {
 844         struct xenbus_device *dev = info->dev;
 845         unsigned int ring_ref, evtchn;
 846         int err;
 847
 848         err = xenbus_gather(XBT_NIL, dev->otherend,
 849                         "ring-ref", "%u", &ring_ref,
 850                         "event-channel", "%u", &evtchn, NULL);
 851         if (err) {
 852                 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
 853                 return err;
 854         }
 855
 856         return scsiback_init_sring(info, ring_ref, evtchn);
 857 }
 858
 859 /*
 860   Add a new translation entry
 861 */
 862 static int scsiback_add_translation_entry(struct vscsibk_info *info,
 863                                           char *phy, struct ids_tuple *v)
 864 {
 865         int err = 0;
 866         struct v2p_entry *entry;
 867         struct v2p_entry *new;
 868         struct list_head *head = &(info->v2p_entry_lists);
 869         unsigned long flags;
 870         char *lunp;
 871         unsigned int lun;
 872         struct scsiback_tpg *tpg_entry, *tpg = NULL;
 873         char *error = "doesn't exist";
 874
 875         lunp = strrchr(phy, ':');
 876         if (!lunp) {
 877                 pr_err("xen-pvscsi: illegal format of physical device %s\n",
 878                         phy);
 879                 return -EINVAL;
 880         }
 881         *lunp = 0;
 882         lunp++;
 883         if (kstrtouint(lunp, 10, &lun) || lun >= TRANSPORT_MAX_LUNS_PER_TPG) {
 884                 pr_err("xen-pvscsi: lun number not valid: %s\n", lunp);
 885                 return -EINVAL;
 886         }
 887
 888         mutex_lock(&scsiback_mutex);
 889         list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
 890                 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
 891                     !strcmp(phy, tpg_entry->param_alias)) {
 892                         spin_lock(&tpg_entry->se_tpg.tpg_lun_lock);
 893                         if (tpg_entry->se_tpg.tpg_lun_list[lun]->lun_status ==
 894                             TRANSPORT_LUN_STATUS_ACTIVE) {
 895                                 if (!tpg_entry->tpg_nexus)
 896                                         error = "nexus undefined";
 897                                 else
 898                                         tpg = tpg_entry;
 899                         }
 900                         spin_unlock(&tpg_entry->se_tpg.tpg_lun_lock);
 901                         break;
 902                 }
 903         }
 904         if (tpg) {
 905                 mutex_lock(&tpg->tv_tpg_mutex);
 906                 tpg->tv_tpg_fe_count++;
 907                 mutex_unlock(&tpg->tv_tpg_mutex);
 908         }
 909         mutex_unlock(&scsiback_mutex);
 910
 911         if (!tpg) {
 912                 pr_err("xen-pvscsi: %s:%d %s\n", phy, lun, error);
 913                 return -ENODEV;
 914         }
 915
 916         new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
 917         if (new == NULL) {
 918                 err = -ENOMEM;
 919                 goto out_free;
 920         }
 921
 922         spin_lock_irqsave(&info->v2p_lock, flags);
 923
 924         /* Check double assignment to identical virtual ID */
 925         list_for_each_entry(entry, head, l) {
 926                 if ((entry->v.chn == v->chn) &&
 927                     (entry->v.tgt == v->tgt) &&
 928                     (entry->v.lun == v->lun)) {
 929                         pr_warn("xen-pvscsi: Virtual ID is already used. Assignment was not performed.\n");
 930                         err = -EEXIST;
 931                         goto out;
 932                 }
 933
 934         }
 935
 936         /* Create a new translation entry and add to the list */
 937         kref_init(&new->kref);
 938         new->v = *v;
 939         new->tpg = tpg;
 940         new->lun = lun;
 941         list_add_tail(&new->l, head);
 942
 943 out:
 944         spin_unlock_irqrestore(&info->v2p_lock, flags);
 945
 946 out_free:
 947         mutex_lock(&tpg->tv_tpg_mutex);
 948         tpg->tv_tpg_fe_count--;
 949         mutex_unlock(&tpg->tv_tpg_mutex);
 950
 951         if (err)
 952                 kfree(new);
 953
 954         return err;
 955 }
 956
 957 static void __scsiback_del_translation_entry(struct v2p_entry *entry)
 958 {
 959         list_del(&entry->l);
 960         kref_put(&entry->kref, scsiback_free_translation_entry);
 961 }
 962
 963 /*
 964   Delete the translation entry specfied
 965 */
 966 static int scsiback_del_translation_entry(struct vscsibk_info *info,
 967                                           struct ids_tuple *v)
 968 {
 969         struct v2p_entry *entry;
 970         struct list_head *head = &(info->v2p_entry_lists);
 971         unsigned long flags;
 972
 973         spin_lock_irqsave(&info->v2p_lock, flags);
 974         /* Find out the translation entry specified */
 975         list_for_each_entry(entry, head, l) {
 976                 if ((entry->v.chn == v->chn) &&
 977                     (entry->v.tgt == v->tgt) &&
 978                     (entry->v.lun == v->lun)) {
 979                         goto found;
 980                 }
 981         }
 982
 983         spin_unlock_irqrestore(&info->v2p_lock, flags);
 984         return 1;
 985
 986 found:
 987         /* Delete the translation entry specfied */
 988         __scsiback_del_translation_entry(entry);
 989
 990         spin_unlock_irqrestore(&info->v2p_lock, flags);
 991         return 0;
 992 }
 993
 994 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
 995                                 char *phy, struct ids_tuple *vir)
 996 {
 997         if (!scsiback_add_translation_entry(info, phy, vir)) {
 998                 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
 999                                   "%d", XenbusStateInitialised)) {
1000                         pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1001                         scsiback_del_translation_entry(info, vir);
1002                 }
1003         } else {
1004                 xenbus_printf(XBT_NIL, info->dev->nodename, state,
1005                               "%d", XenbusStateClosed);
1006         }
1007 }
1008
1009 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1010                                 struct ids_tuple *vir)
1011 {
1012         if (!scsiback_del_translation_entry(info, vir)) {
1013                 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1014                                   "%d", XenbusStateClosed))
1015                         pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1016         }
1017 }
1018
1019 #define VSCSIBACK_OP_ADD_OR_DEL_LUN     1
1020 #define VSCSIBACK_OP_UPDATEDEV_STATE    2
1021
1022 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1023                                      char *ent)
1024 {
1025         int err;
1026         struct ids_tuple vir;
1027         char *val;
1028         int device_state;
1029         char phy[VSCSI_NAMELEN];
1030         char str[64];
1031         char state[64];
1032         struct xenbus_device *dev = info->dev;
1033
1034         /* read status */
1035         snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1036         err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1037         if (XENBUS_EXIST_ERR(err))
1038                 return;
1039
1040         /* physical SCSI device */
1041         snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1042         val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1043         if (IS_ERR(val)) {
1044                 xenbus_printf(XBT_NIL, dev->nodename, state,
1045                               "%d", XenbusStateClosed);
1046                 return;
1047         }
1048         strlcpy(phy, val, VSCSI_NAMELEN);
1049         kfree(val);
1050
1051         /* virtual SCSI device */
1052         snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1053         err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1054                            &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1055         if (XENBUS_EXIST_ERR(err)) {
1056                 xenbus_printf(XBT_NIL, dev->nodename, state,
1057                               "%d", XenbusStateClosed);
1058                 return;
1059         }
1060
1061         switch (op) {
1062         case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1063                 if (device_state == XenbusStateInitialising)
1064                         scsiback_do_add_lun(info, state, phy, &vir);
1065                 if (device_state == XenbusStateClosing)
1066                         scsiback_do_del_lun(info, state, &vir);
1067                 break;
1068
1069         case VSCSIBACK_OP_UPDATEDEV_STATE:
1070                 if (device_state == XenbusStateInitialised) {
1071                         /* modify vscsi-devs/dev-x/state */
1072                         if (xenbus_printf(XBT_NIL, dev->nodename, state,
1073                                           "%d", XenbusStateConnected)) {
1074                                 pr_err("xen-pvscsi: xenbus_printf error %s\n",
1075                                        str);
1076                                 scsiback_del_translation_entry(info, &vir);
1077                                 xenbus_printf(XBT_NIL, dev->nodename, state,
1078                                               "%d", XenbusStateClosed);
1079                         }
1080                 }
1081                 break;
1082         /*When it is necessary, processing is added here.*/
1083         default:
1084                 break;
1085         }
1086 }
1087
1088 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1089 {
1090         int i;
1091         char **dir;
1092         unsigned int ndir = 0;
1093
1094         dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1095                                &ndir);
1096         if (IS_ERR(dir))
1097                 return;
1098
1099         for (i = 0; i < ndir; i++)
1100                 scsiback_do_1lun_hotplug(info, op, dir[i]);
1101
1102         kfree(dir);
1103 }
1104
1105 static void scsiback_frontend_changed(struct xenbus_device *dev,
1106                                         enum xenbus_state frontend_state)
1107 {
1108         struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1109
1110         switch (frontend_state) {
1111         case XenbusStateInitialising:
1112                 break;
1113
1114         case XenbusStateInitialised:
1115                 if (scsiback_map(info))
1116                         break;
1117
1118                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1119                 xenbus_switch_state(dev, XenbusStateConnected);
1120                 break;
1121
1122         case XenbusStateConnected:
1123                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1124
1125                 if (dev->state == XenbusStateConnected)
1126                         break;
1127
1128                 xenbus_switch_state(dev, XenbusStateConnected);
1129                 break;
1130
1131         case XenbusStateClosing:
1132                 if (info->irq)
1133                         scsiback_disconnect(info);
1134
1135                 xenbus_switch_state(dev, XenbusStateClosing);
1136                 break;
1137
1138         case XenbusStateClosed:
1139                 xenbus_switch_state(dev, XenbusStateClosed);
1140                 if (xenbus_dev_is_online(dev))
1141                         break;
1142                 /* fall through if not online */
1143         case XenbusStateUnknown:
1144                 device_unregister(&dev->dev);
1145                 break;
1146
1147         case XenbusStateReconfiguring:
1148                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1149                 xenbus_switch_state(dev, XenbusStateReconfigured);
1150
1151                 break;
1152
1153         default:
1154                 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1155                                         frontend_state);
1156                 break;
1157         }
1158 }
1159
1160 /*
1161   Release the translation entry specfied
1162 */
1163 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1164 {
1165         struct v2p_entry *entry, *tmp;
1166         struct list_head *head = &(info->v2p_entry_lists);
1167         unsigned long flags;
1168
1169         spin_lock_irqsave(&info->v2p_lock, flags);
1170
1171         list_for_each_entry_safe(entry, tmp, head, l)
1172                 __scsiback_del_translation_entry(entry);
1173
1174         spin_unlock_irqrestore(&info->v2p_lock, flags);
1175 }
1176
1177 static int scsiback_remove(struct xenbus_device *dev)
1178 {
1179         struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1180
1181         if (info->irq)
1182                 scsiback_disconnect(info);
1183
1184         scsiback_release_translation_entry(info);
1185
1186         dev_set_drvdata(&dev->dev, NULL);
1187
1188         return 0;
1189 }
1190
1191 static int scsiback_probe(struct xenbus_device *dev,
1192                            const struct xenbus_device_id *id)
1193 {
1194         int err;
1195
1196         struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1197                                             GFP_KERNEL);
1198
1199         DPRINTK("%p %d\n", dev, dev->otherend_id);
1200
1201         if (!info) {
1202                 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1203                 return -ENOMEM;
1204         }
1205         info->dev = dev;
1206         dev_set_drvdata(&dev->dev, info);
1207
1208         info->domid = dev->otherend_id;
1209         spin_lock_init(&info->ring_lock);
1210         info->ring_error = 0;
1211         atomic_set(&info->nr_unreplied_reqs, 0);
1212         init_waitqueue_head(&info->waiting_to_free);
1213         info->dev = dev;
1214         info->irq = 0;
1215         INIT_LIST_HEAD(&info->v2p_entry_lists);
1216         spin_lock_init(&info->v2p_lock);
1217
1218         err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1219                             SG_ALL);
1220         if (err)
1221                 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1222
1223         err = xenbus_switch_state(dev, XenbusStateInitWait);
1224         if (err)
1225                 goto fail;
1226
1227         return 0;
1228
1229 fail:
1230         pr_warn("xen-pvscsi: %s failed\n", __func__);
1231         scsiback_remove(dev);
1232
1233         return err;
1234 }
1235
1236 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1237 {
1238         switch (tport->tport_proto_id) {
1239         case SCSI_PROTOCOL_SAS:
1240                 return "SAS";
1241         case SCSI_PROTOCOL_FCP:
1242                 return "FCP";
1243         case SCSI_PROTOCOL_ISCSI:
1244                 return "iSCSI";
1245         default:
1246                 break;
1247         }
1248
1249         return "Unknown";
1250 }
1251
1252 static u8 scsiback_get_fabric_proto_ident(struct se_portal_group *se_tpg)
1253 {
1254         struct scsiback_tpg *tpg = container_of(se_tpg,
1255                                 struct scsiback_tpg, se_tpg);
1256         struct scsiback_tport *tport = tpg->tport;
1257
1258         switch (tport->tport_proto_id) {
1259         case SCSI_PROTOCOL_SAS:
1260                 return sas_get_fabric_proto_ident(se_tpg);
1261         case SCSI_PROTOCOL_FCP:
1262                 return fc_get_fabric_proto_ident(se_tpg);
1263         case SCSI_PROTOCOL_ISCSI:
1264                 return iscsi_get_fabric_proto_ident(se_tpg);
1265         default:
1266                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1267                         tport->tport_proto_id);
1268                 break;
1269         }
1270
1271         return sas_get_fabric_proto_ident(se_tpg);
1272 }
1273
1274 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1275 {
1276         struct scsiback_tpg *tpg = container_of(se_tpg,
1277                                 struct scsiback_tpg, se_tpg);
1278         struct scsiback_tport *tport = tpg->tport;
1279
1280         return &tport->tport_name[0];
1281 }
1282
1283 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1284 {
1285         struct scsiback_tpg *tpg = container_of(se_tpg,
1286                                 struct scsiback_tpg, se_tpg);
1287         return tpg->tport_tpgt;
1288 }
1289
1290 static u32 scsiback_get_default_depth(struct se_portal_group *se_tpg)
1291 {
1292         return 1;
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("xen-pvscsi: 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("xen-pvscsi: 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
1474          * pointer.  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         /*
1663          * Now register the TCM pvscsi virtual I_T Nexus as active with the
1664          * call to __transport_register_session()
1665          */
1666         __transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
1667                         tv_nexus->tvn_se_sess, tv_nexus);
1668         tpg->tpg_nexus = tv_nexus;
1669
1670         mutex_unlock(&tpg->tv_tpg_mutex);
1671         return 0;
1672
1673 out:
1674         transport_free_session(se_sess);
1675         kfree(tv_nexus);
1676         return -ENOMEM;
1677 }
1678
1679 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1680 {
1681         struct se_session *se_sess;
1682         struct scsiback_nexus *tv_nexus;
1683
1684         mutex_lock(&tpg->tv_tpg_mutex);
1685         tv_nexus = tpg->tpg_nexus;
1686         if (!tv_nexus) {
1687                 mutex_unlock(&tpg->tv_tpg_mutex);
1688                 return -ENODEV;
1689         }
1690
1691         se_sess = tv_nexus->tvn_se_sess;
1692         if (!se_sess) {
1693                 mutex_unlock(&tpg->tv_tpg_mutex);
1694                 return -ENODEV;
1695         }
1696
1697         if (tpg->tv_tpg_port_count != 0) {
1698                 mutex_unlock(&tpg->tv_tpg_mutex);
1699                 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1700                         tpg->tv_tpg_port_count);
1701                 return -EBUSY;
1702         }
1703
1704         if (tpg->tv_tpg_fe_count != 0) {
1705                 mutex_unlock(&tpg->tv_tpg_mutex);
1706                 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1707                         tpg->tv_tpg_fe_count);
1708                 return -EBUSY;
1709         }
1710
1711         pr_debug("xen-pvscsi: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1712                 scsiback_dump_proto_id(tpg->tport),
1713                 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1714
1715         /*
1716          * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1717          */
1718         transport_deregister_session(tv_nexus->tvn_se_sess);
1719         tpg->tpg_nexus = NULL;
1720         mutex_unlock(&tpg->tv_tpg_mutex);
1721
1722         kfree(tv_nexus);
1723         return 0;
1724 }
1725
1726 static ssize_t scsiback_tpg_show_nexus(struct se_portal_group *se_tpg,
1727                                         char *page)
1728 {
1729         struct scsiback_tpg *tpg = container_of(se_tpg,
1730                                 struct scsiback_tpg, se_tpg);
1731         struct scsiback_nexus *tv_nexus;
1732         ssize_t ret;
1733
1734         mutex_lock(&tpg->tv_tpg_mutex);
1735         tv_nexus = tpg->tpg_nexus;
1736         if (!tv_nexus) {
1737                 mutex_unlock(&tpg->tv_tpg_mutex);
1738                 return -ENODEV;
1739         }
1740         ret = snprintf(page, PAGE_SIZE, "%s\n",
1741                         tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1742         mutex_unlock(&tpg->tv_tpg_mutex);
1743
1744         return ret;
1745 }
1746
1747 static ssize_t scsiback_tpg_store_nexus(struct se_portal_group *se_tpg,
1748                                          const char *page,
1749                                          size_t count)
1750 {
1751         struct scsiback_tpg *tpg = container_of(se_tpg,
1752                                 struct scsiback_tpg, se_tpg);
1753         struct scsiback_tport *tport_wwn = tpg->tport;
1754         unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1755         int ret;
1756         /*
1757          * Shutdown the active I_T nexus if 'NULL' is passed..
1758          */
1759         if (!strncmp(page, "NULL", 4)) {
1760                 ret = scsiback_drop_nexus(tpg);
1761                 return (!ret) ? count : ret;
1762         }
1763         /*
1764          * Otherwise make sure the passed virtual Initiator port WWN matches
1765          * the fabric protocol_id set in scsiback_make_tport(), and call
1766          * scsiback_make_nexus().
1767          */
1768         if (strlen(page) >= VSCSI_NAMELEN) {
1769                 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1770                         page, VSCSI_NAMELEN);
1771                 return -EINVAL;
1772         }
1773         snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1774
1775         ptr = strstr(i_port, "naa.");
1776         if (ptr) {
1777                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1778                         pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1779                                 i_port, scsiback_dump_proto_id(tport_wwn));
1780                         return -EINVAL;
1781                 }
1782                 port_ptr = &i_port[0];
1783                 goto check_newline;
1784         }
1785         ptr = strstr(i_port, "fc.");
1786         if (ptr) {
1787                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1788                         pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1789                                 i_port, scsiback_dump_proto_id(tport_wwn));
1790                         return -EINVAL;
1791                 }
1792                 port_ptr = &i_port[3]; /* Skip over "fc." */
1793                 goto check_newline;
1794         }
1795         ptr = strstr(i_port, "iqn.");
1796         if (ptr) {
1797                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1798                         pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1799                                 i_port, scsiback_dump_proto_id(tport_wwn));
1800                         return -EINVAL;
1801                 }
1802                 port_ptr = &i_port[0];
1803                 goto check_newline;
1804         }
1805         pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1806                 i_port);
1807         return -EINVAL;
1808         /*
1809          * Clear any trailing newline for the NAA WWN
1810          */
1811 check_newline:
1812         if (i_port[strlen(i_port) - 1] == '\n')
1813                 i_port[strlen(i_port) - 1] = '\0';
1814
1815         ret = scsiback_make_nexus(tpg, port_ptr);
1816         if (ret < 0)
1817                 return ret;
1818
1819         return count;
1820 }
1821
1822 TF_TPG_BASE_ATTR(scsiback, nexus, S_IRUGO | S_IWUSR);
1823
1824 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1825         &scsiback_tpg_nexus.attr,
1826         NULL,
1827 };
1828
1829 static ssize_t
1830 scsiback_wwn_show_attr_version(struct target_fabric_configfs *tf,
1831                                 char *page)
1832 {
1833         return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1834                 UTS_RELEASE"\n",
1835                 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1836 }
1837
1838 TF_WWN_ATTR_RO(scsiback, version);
1839
1840 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1841         &scsiback_wwn_version.attr,
1842         NULL,
1843 };
1844
1845 static char *scsiback_get_fabric_name(void)
1846 {
1847         return "xen-pvscsi";
1848 }
1849
1850 static int scsiback_port_link(struct se_portal_group *se_tpg,
1851                                struct se_lun *lun)
1852 {
1853         struct scsiback_tpg *tpg = container_of(se_tpg,
1854                                 struct scsiback_tpg, se_tpg);
1855
1856         mutex_lock(&tpg->tv_tpg_mutex);
1857         tpg->tv_tpg_port_count++;
1858         mutex_unlock(&tpg->tv_tpg_mutex);
1859
1860         return 0;
1861 }
1862
1863 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1864                                   struct se_lun *lun)
1865 {
1866         struct scsiback_tpg *tpg = container_of(se_tpg,
1867                                 struct scsiback_tpg, se_tpg);
1868
1869         mutex_lock(&tpg->tv_tpg_mutex);
1870         tpg->tv_tpg_port_count--;
1871         mutex_unlock(&tpg->tv_tpg_mutex);
1872 }
1873
1874 static struct se_portal_group *
1875 scsiback_make_tpg(struct se_wwn *wwn,
1876                    struct config_group *group,
1877                    const char *name)
1878 {
1879         struct scsiback_tport *tport = container_of(wwn,
1880                         struct scsiback_tport, tport_wwn);
1881
1882         struct scsiback_tpg *tpg;
1883         u16 tpgt;
1884         int ret;
1885
1886         if (strstr(name, "tpgt_") != name)
1887                 return ERR_PTR(-EINVAL);
1888         ret = kstrtou16(name + 5, 10, &tpgt);
1889         if (ret)
1890                 return ERR_PTR(ret);
1891
1892         tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1893         if (!tpg)
1894                 return ERR_PTR(-ENOMEM);
1895
1896         mutex_init(&tpg->tv_tpg_mutex);
1897         INIT_LIST_HEAD(&tpg->tv_tpg_list);
1898         INIT_LIST_HEAD(&tpg->info_list);
1899         tpg->tport = tport;
1900         tpg->tport_tpgt = tpgt;
1901
1902         ret = core_tpg_register(&scsiback_fabric_configfs->tf_ops, wwn,
1903                                 &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
1904         if (ret < 0) {
1905                 kfree(tpg);
1906                 return NULL;
1907         }
1908         mutex_lock(&scsiback_mutex);
1909         list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1910         mutex_unlock(&scsiback_mutex);
1911
1912         return &tpg->se_tpg;
1913 }
1914
1915 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1916 {
1917         struct scsiback_tpg *tpg = container_of(se_tpg,
1918                                 struct scsiback_tpg, se_tpg);
1919
1920         mutex_lock(&scsiback_mutex);
1921         list_del(&tpg->tv_tpg_list);
1922         mutex_unlock(&scsiback_mutex);
1923         /*
1924          * Release the virtual I_T Nexus for this xen-pvscsi TPG
1925          */
1926         scsiback_drop_nexus(tpg);
1927         /*
1928          * Deregister the se_tpg from TCM..
1929          */
1930         core_tpg_deregister(se_tpg);
1931         kfree(tpg);
1932 }
1933
1934 static int scsiback_check_true(struct se_portal_group *se_tpg)
1935 {
1936         return 1;
1937 }
1938
1939 static int scsiback_check_false(struct se_portal_group *se_tpg)
1940 {
1941         return 0;
1942 }
1943
1944 static struct target_core_fabric_ops scsiback_ops = {
1945         .get_fabric_name                = scsiback_get_fabric_name,
1946         .get_fabric_proto_ident         = scsiback_get_fabric_proto_ident,
1947         .tpg_get_wwn                    = scsiback_get_fabric_wwn,
1948         .tpg_get_tag                    = scsiback_get_tag,
1949         .tpg_get_default_depth          = scsiback_get_default_depth,
1950         .tpg_get_pr_transport_id        = scsiback_get_pr_transport_id,
1951         .tpg_get_pr_transport_id_len    = scsiback_get_pr_transport_id_len,
1952         .tpg_parse_pr_out_transport_id  = scsiback_parse_pr_out_transport_id,
1953         .tpg_check_demo_mode            = scsiback_check_true,
1954         .tpg_check_demo_mode_cache      = scsiback_check_true,
1955         .tpg_check_demo_mode_write_protect = scsiback_check_false,
1956         .tpg_check_prod_mode_write_protect = scsiback_check_false,
1957         .tpg_alloc_fabric_acl           = scsiback_alloc_fabric_acl,
1958         .tpg_release_fabric_acl         = scsiback_release_fabric_acl,
1959         .tpg_get_inst_index             = scsiback_tpg_get_inst_index,
1960         .check_stop_free                = scsiback_check_stop_free,
1961         .release_cmd                    = scsiback_release_cmd,
1962         .put_session                    = NULL,
1963         .shutdown_session               = scsiback_shutdown_session,
1964         .close_session                  = scsiback_close_session,
1965         .sess_get_index                 = scsiback_sess_get_index,
1966         .sess_get_initiator_sid         = NULL,
1967         .write_pending                  = scsiback_write_pending,
1968         .write_pending_status           = scsiback_write_pending_status,
1969         .set_default_node_attributes    = scsiback_set_default_node_attrs,
1970         .get_task_tag                   = scsiback_get_task_tag,
1971         .get_cmd_state                  = scsiback_get_cmd_state,
1972         .queue_data_in                  = scsiback_queue_data_in,
1973         .queue_status                   = scsiback_queue_status,
1974         .queue_tm_rsp                   = scsiback_queue_tm_rsp,
1975         .aborted_task                   = scsiback_aborted_task,
1976         /*
1977          * Setup callers for generic logic in target_core_fabric_configfs.c
1978          */
1979         .fabric_make_wwn                = scsiback_make_tport,
1980         .fabric_drop_wwn                = scsiback_drop_tport,
1981         .fabric_make_tpg                = scsiback_make_tpg,
1982         .fabric_drop_tpg                = scsiback_drop_tpg,
1983         .fabric_post_link               = scsiback_port_link,
1984         .fabric_pre_unlink              = scsiback_port_unlink,
1985         .fabric_make_np                 = NULL,
1986         .fabric_drop_np                 = NULL,
1987 #if 0
1988         .fabric_make_nodeacl            = scsiback_make_nodeacl,
1989         .fabric_drop_nodeacl            = scsiback_drop_nodeacl,
1990 #endif
1991 };
1992
1993 static int scsiback_register_configfs(void)
1994 {
1995         struct target_fabric_configfs *fabric;
1996         int ret;
1997
1998         pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
1999                  VSCSI_VERSION, utsname()->sysname, utsname()->machine);
2000         /*
2001          * Register the top level struct config_item_type with TCM core
2002          */
2003         fabric = target_fabric_configfs_init(THIS_MODULE, "xen-pvscsi");
2004         if (IS_ERR(fabric))
2005                 return PTR_ERR(fabric);
2006
2007         /*
2008          * Setup fabric->tf_ops from our local scsiback_ops
2009          */
2010         fabric->tf_ops = scsiback_ops;
2011         /*
2012          * Setup default attribute lists for various fabric->tf_cit_tmpl
2013          */
2014         fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = scsiback_wwn_attrs;
2015         fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = scsiback_tpg_attrs;
2016         fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
2017         fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = scsiback_param_attrs;
2018         fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
2019         fabric->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
2020         fabric->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
2021         fabric->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
2022         fabric->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
2023         /*
2024          * Register the fabric for use within TCM
2025          */
2026         ret = target_fabric_configfs_register(fabric);
2027         if (ret < 0) {
2028                 target_fabric_configfs_free(fabric);
2029                 return ret;
2030         }
2031         /*
2032          * Setup our local pointer to *fabric
2033          */
2034         scsiback_fabric_configfs = fabric;
2035         pr_debug("xen-pvscsi: Set fabric -> scsiback_fabric_configfs\n");
2036         return 0;
2037 };
2038
2039 static void scsiback_deregister_configfs(void)
2040 {
2041         if (!scsiback_fabric_configfs)
2042                 return;
2043
2044         target_fabric_configfs_deregister(scsiback_fabric_configfs);
2045         scsiback_fabric_configfs = NULL;
2046         pr_debug("xen-pvscsi: Cleared scsiback_fabric_configfs\n");
2047 };
2048
2049 static const struct xenbus_device_id scsiback_ids[] = {
2050         { "vscsi" },
2051         { "" }
2052 };
2053
2054 static struct xenbus_driver scsiback_driver = {
2055         .ids                    = scsiback_ids,
2056         .probe                  = scsiback_probe,
2057         .remove                 = scsiback_remove,
2058         .otherend_changed       = scsiback_frontend_changed
2059 };
2060
2061 static void scsiback_init_pend(void *p)
2062 {
2063         struct vscsibk_pend *pend = p;
2064         int i;
2065
2066         memset(pend, 0, sizeof(*pend));
2067         for (i = 0; i < VSCSI_MAX_GRANTS; i++)
2068                 pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
2069 }
2070
2071 static int __init scsiback_init(void)
2072 {
2073         int ret;
2074
2075         if (!xen_domain())
2076                 return -ENODEV;
2077
2078         scsiback_cachep = kmem_cache_create("vscsiif_cache",
2079                 sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
2080         if (!scsiback_cachep)
2081                 return -ENOMEM;
2082
2083         ret = xenbus_register_backend(&scsiback_driver);
2084         if (ret)
2085                 goto out_cache_destroy;
2086
2087         ret = scsiback_register_configfs();
2088         if (ret)
2089                 goto out_unregister_xenbus;
2090
2091         return 0;
2092
2093 out_unregister_xenbus:
2094         xenbus_unregister_driver(&scsiback_driver);
2095 out_cache_destroy:
2096         kmem_cache_destroy(scsiback_cachep);
2097         pr_err("xen-pvscsi: %s: error %d\n", __func__, ret);
2098         return ret;
2099 }
2100
2101 static void __exit scsiback_exit(void)
2102 {
2103         struct page *page;
2104
2105         while (free_pages_num) {
2106                 if (get_free_page(&page))
2107                         BUG();
2108                 gnttab_free_pages(1, &page);
2109         }
2110         scsiback_deregister_configfs();
2111         xenbus_unregister_driver(&scsiback_driver);
2112         kmem_cache_destroy(scsiback_cachep);
2113 }
2114
2115 module_init(scsiback_init);
2116 module_exit(scsiback_exit);
2117
2118 MODULE_DESCRIPTION("Xen SCSI backend driver");
2119 MODULE_LICENSE("Dual BSD/GPL");
2120 MODULE_ALIAS("xen-backend:vscsi");
2121 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");