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         uint8_t act;
 718
 719         rc = ring->req_cons;
 720         rp = ring->sring->req_prod;
 721         rmb();  /* guest system is accessing ring, too */
 722
 723         if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
 724                 rc = ring->rsp_prod_pvt;
 725                 pr_warn("xen-pvscsi: Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
 726                            info->domid, rp, rc, rp - rc);
 727                 info->ring_error = 1;
 728                 return 0;
 729         }
 730
 731         while ((rc != rp)) {
 732                 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
 733                         break;
 734                 pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL);
 735                 if (!pending_req)
 736                         return 1;
 737
 738                 ring_req = RING_GET_REQUEST(ring, rc);
 739                 ring->req_cons = ++rc;
 740
 741                 act = ring_req->act;
 742                 err = prepare_pending_reqs(info, ring_req, pending_req);
 743                 if (err) {
 744                         switch (err) {
 745                         case -ENODEV:
 746                                 result = DID_NO_CONNECT;
 747                                 break;
 748                         default:
 749                                 result = DRIVER_ERROR;
 750                                 break;
 751                         }
 752                         scsiback_do_resp_with_sense(NULL, result << 24, 0,
 753                                                     pending_req);
 754                         kmem_cache_free(scsiback_cachep, pending_req);
 755                         return 1;
 756                 }
 757
 758                 switch (act) {
 759                 case VSCSIIF_ACT_SCSI_CDB:
 760                         if (scsiback_gnttab_data_map(ring_req, pending_req)) {
 761                                 scsiback_fast_flush_area(pending_req);
 762                                 scsiback_do_resp_with_sense(NULL,
 763                                         DRIVER_ERROR << 24, 0, pending_req);
 764                                 kmem_cache_free(scsiback_cachep, pending_req);
 765                         } else {
 766                                 scsiback_cmd_exec(pending_req);
 767                         }
 768                         break;
 769                 case VSCSIIF_ACT_SCSI_ABORT:
 770                         scsiback_device_action(pending_req, TMR_ABORT_TASK,
 771                                 ring_req->ref_rqid);
 772                         break;
 773                 case VSCSIIF_ACT_SCSI_RESET:
 774                         scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
 775                         break;
 776                 default:
 777                         pr_err_ratelimited("xen-pvscsi: invalid request\n");
 778                         scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24,
 779                                                     0, pending_req);
 780                         kmem_cache_free(scsiback_cachep, pending_req);
 781                         break;
 782                 }
 783
 784                 /* Yield point for this unbounded loop. */
 785                 cond_resched();
 786         }
 787
 788         RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
 789         return more_to_do;
 790 }
 791
 792 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
 793 {
 794         struct vscsibk_info *info = dev_id;
 795
 796         if (info->ring_error)
 797                 return IRQ_HANDLED;
 798
 799         while (scsiback_do_cmd_fn(info))
 800                 cond_resched();
 801
 802         return IRQ_HANDLED;
 803 }
 804
 805 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
 806                         evtchn_port_t evtchn)
 807 {
 808         void *area;
 809         struct vscsiif_sring *sring;
 810         int err;
 811
 812         if (info->irq)
 813                 return -1;
 814
 815         err = xenbus_map_ring_valloc(info->dev, ring_ref, &area);
 816         if (err)
 817                 return err;
 818
 819         sring = (struct vscsiif_sring *)area;
 820         BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
 821
 822         err = bind_interdomain_evtchn_to_irq(info->domid, evtchn);
 823         if (err < 0)
 824                 goto unmap_page;
 825
 826         info->irq = err;
 827
 828         err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
 829                                    IRQF_ONESHOT, "vscsiif-backend", info);
 830         if (err)
 831                 goto free_irq;
 832
 833         return 0;
 834
 835 free_irq:
 836         unbind_from_irqhandler(info->irq, info);
 837         info->irq = 0;
 838 unmap_page:
 839         xenbus_unmap_ring_vfree(info->dev, area);
 840
 841         return err;
 842 }
 843
 844 static int scsiback_map(struct vscsibk_info *info)
 845 {
 846         struct xenbus_device *dev = info->dev;
 847         unsigned int ring_ref, evtchn;
 848         int err;
 849
 850         err = xenbus_gather(XBT_NIL, dev->otherend,
 851                         "ring-ref", "%u", &ring_ref,
 852                         "event-channel", "%u", &evtchn, NULL);
 853         if (err) {
 854                 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
 855                 return err;
 856         }
 857
 858         return scsiback_init_sring(info, ring_ref, evtchn);
 859 }
 860
 861 /*
 862   Add a new translation entry
 863 */
 864 static int scsiback_add_translation_entry(struct vscsibk_info *info,
 865                                           char *phy, struct ids_tuple *v)
 866 {
 867         int err = 0;
 868         struct v2p_entry *entry;
 869         struct v2p_entry *new;
 870         struct list_head *head = &(info->v2p_entry_lists);
 871         unsigned long flags;
 872         char *lunp;
 873         unsigned int lun;
 874         struct scsiback_tpg *tpg_entry, *tpg = NULL;
 875         char *error = "doesn't exist";
 876
 877         lunp = strrchr(phy, ':');
 878         if (!lunp) {
 879                 pr_err("xen-pvscsi: illegal format of physical device %s\n",
 880                         phy);
 881                 return -EINVAL;
 882         }
 883         *lunp = 0;
 884         lunp++;
 885         if (kstrtouint(lunp, 10, &lun) || lun >= TRANSPORT_MAX_LUNS_PER_TPG) {
 886                 pr_err("xen-pvscsi: lun number not valid: %s\n", lunp);
 887                 return -EINVAL;
 888         }
 889
 890         mutex_lock(&scsiback_mutex);
 891         list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
 892                 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
 893                     !strcmp(phy, tpg_entry->param_alias)) {
 894                         spin_lock(&tpg_entry->se_tpg.tpg_lun_lock);
 895                         if (tpg_entry->se_tpg.tpg_lun_list[lun]->lun_status ==
 896                             TRANSPORT_LUN_STATUS_ACTIVE) {
 897                                 if (!tpg_entry->tpg_nexus)
 898                                         error = "nexus undefined";
 899                                 else
 900                                         tpg = tpg_entry;
 901                         }
 902                         spin_unlock(&tpg_entry->se_tpg.tpg_lun_lock);
 903                         break;
 904                 }
 905         }
 906         if (tpg) {
 907                 mutex_lock(&tpg->tv_tpg_mutex);
 908                 tpg->tv_tpg_fe_count++;
 909                 mutex_unlock(&tpg->tv_tpg_mutex);
 910         }
 911         mutex_unlock(&scsiback_mutex);
 912
 913         if (!tpg) {
 914                 pr_err("xen-pvscsi: %s:%d %s\n", phy, lun, error);
 915                 return -ENODEV;
 916         }
 917
 918         new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
 919         if (new == NULL) {
 920                 err = -ENOMEM;
 921                 goto out_free;
 922         }
 923
 924         spin_lock_irqsave(&info->v2p_lock, flags);
 925
 926         /* Check double assignment to identical virtual ID */
 927         list_for_each_entry(entry, head, l) {
 928                 if ((entry->v.chn == v->chn) &&
 929                     (entry->v.tgt == v->tgt) &&
 930                     (entry->v.lun == v->lun)) {
 931                         pr_warn("xen-pvscsi: Virtual ID is already used. Assignment was not performed.\n");
 932                         err = -EEXIST;
 933                         goto out;
 934                 }
 935
 936         }
 937
 938         /* Create a new translation entry and add to the list */
 939         kref_init(&new->kref);
 940         new->v = *v;
 941         new->tpg = tpg;
 942         new->lun = lun;
 943         list_add_tail(&new->l, head);
 944
 945 out:
 946         spin_unlock_irqrestore(&info->v2p_lock, flags);
 947
 948 out_free:
 949         mutex_lock(&tpg->tv_tpg_mutex);
 950         tpg->tv_tpg_fe_count--;
 951         mutex_unlock(&tpg->tv_tpg_mutex);
 952
 953         if (err)
 954                 kfree(new);
 955
 956         return err;
 957 }
 958
 959 static void __scsiback_del_translation_entry(struct v2p_entry *entry)
 960 {
 961         list_del(&entry->l);
 962         kref_put(&entry->kref, scsiback_free_translation_entry);
 963 }
 964
 965 /*
 966   Delete the translation entry specfied
 967 */
 968 static int scsiback_del_translation_entry(struct vscsibk_info *info,
 969                                           struct ids_tuple *v)
 970 {
 971         struct v2p_entry *entry;
 972         struct list_head *head = &(info->v2p_entry_lists);
 973         unsigned long flags;
 974
 975         spin_lock_irqsave(&info->v2p_lock, flags);
 976         /* Find out the translation entry specified */
 977         list_for_each_entry(entry, head, l) {
 978                 if ((entry->v.chn == v->chn) &&
 979                     (entry->v.tgt == v->tgt) &&
 980                     (entry->v.lun == v->lun)) {
 981                         goto found;
 982                 }
 983         }
 984
 985         spin_unlock_irqrestore(&info->v2p_lock, flags);
 986         return 1;
 987
 988 found:
 989         /* Delete the translation entry specfied */
 990         __scsiback_del_translation_entry(entry);
 991
 992         spin_unlock_irqrestore(&info->v2p_lock, flags);
 993         return 0;
 994 }
 995
 996 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
 997                                 char *phy, struct ids_tuple *vir)
 998 {
 999         if (!scsiback_add_translation_entry(info, phy, vir)) {
1000                 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1001                                   "%d", XenbusStateInitialised)) {
1002                         pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1003                         scsiback_del_translation_entry(info, vir);
1004                 }
1005         } else {
1006                 xenbus_printf(XBT_NIL, info->dev->nodename, state,
1007                               "%d", XenbusStateClosed);
1008         }
1009 }
1010
1011 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1012                                 struct ids_tuple *vir)
1013 {
1014         if (!scsiback_del_translation_entry(info, vir)) {
1015                 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1016                                   "%d", XenbusStateClosed))
1017                         pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1018         }
1019 }
1020
1021 #define VSCSIBACK_OP_ADD_OR_DEL_LUN     1
1022 #define VSCSIBACK_OP_UPDATEDEV_STATE    2
1023
1024 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1025                                      char *ent)
1026 {
1027         int err;
1028         struct ids_tuple vir;
1029         char *val;
1030         int device_state;
1031         char phy[VSCSI_NAMELEN];
1032         char str[64];
1033         char state[64];
1034         struct xenbus_device *dev = info->dev;
1035
1036         /* read status */
1037         snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1038         err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1039         if (XENBUS_EXIST_ERR(err))
1040                 return;
1041
1042         /* physical SCSI device */
1043         snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1044         val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1045         if (IS_ERR(val)) {
1046                 xenbus_printf(XBT_NIL, dev->nodename, state,
1047                               "%d", XenbusStateClosed);
1048                 return;
1049         }
1050         strlcpy(phy, val, VSCSI_NAMELEN);
1051         kfree(val);
1052
1053         /* virtual SCSI device */
1054         snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1055         err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1056                            &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1057         if (XENBUS_EXIST_ERR(err)) {
1058                 xenbus_printf(XBT_NIL, dev->nodename, state,
1059                               "%d", XenbusStateClosed);
1060                 return;
1061         }
1062
1063         switch (op) {
1064         case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1065                 if (device_state == XenbusStateInitialising)
1066                         scsiback_do_add_lun(info, state, phy, &vir);
1067                 if (device_state == XenbusStateClosing)
1068                         scsiback_do_del_lun(info, state, &vir);
1069                 break;
1070
1071         case VSCSIBACK_OP_UPDATEDEV_STATE:
1072                 if (device_state == XenbusStateInitialised) {
1073                         /* modify vscsi-devs/dev-x/state */
1074                         if (xenbus_printf(XBT_NIL, dev->nodename, state,
1075                                           "%d", XenbusStateConnected)) {
1076                                 pr_err("xen-pvscsi: xenbus_printf error %s\n",
1077                                        str);
1078                                 scsiback_del_translation_entry(info, &vir);
1079                                 xenbus_printf(XBT_NIL, dev->nodename, state,
1080                                               "%d", XenbusStateClosed);
1081                         }
1082                 }
1083                 break;
1084         /*When it is necessary, processing is added here.*/
1085         default:
1086                 break;
1087         }
1088 }
1089
1090 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1091 {
1092         int i;
1093         char **dir;
1094         unsigned int ndir = 0;
1095
1096         dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1097                                &ndir);
1098         if (IS_ERR(dir))
1099                 return;
1100
1101         for (i = 0; i < ndir; i++)
1102                 scsiback_do_1lun_hotplug(info, op, dir[i]);
1103
1104         kfree(dir);
1105 }
1106
1107 static void scsiback_frontend_changed(struct xenbus_device *dev,
1108                                         enum xenbus_state frontend_state)
1109 {
1110         struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1111
1112         switch (frontend_state) {
1113         case XenbusStateInitialising:
1114                 break;
1115
1116         case XenbusStateInitialised:
1117                 if (scsiback_map(info))
1118                         break;
1119
1120                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1121                 xenbus_switch_state(dev, XenbusStateConnected);
1122                 break;
1123
1124         case XenbusStateConnected:
1125                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1126
1127                 if (dev->state == XenbusStateConnected)
1128                         break;
1129
1130                 xenbus_switch_state(dev, XenbusStateConnected);
1131                 break;
1132
1133         case XenbusStateClosing:
1134                 if (info->irq)
1135                         scsiback_disconnect(info);
1136
1137                 xenbus_switch_state(dev, XenbusStateClosing);
1138                 break;
1139
1140         case XenbusStateClosed:
1141                 xenbus_switch_state(dev, XenbusStateClosed);
1142                 if (xenbus_dev_is_online(dev))
1143                         break;
1144                 /* fall through if not online */
1145         case XenbusStateUnknown:
1146                 device_unregister(&dev->dev);
1147                 break;
1148
1149         case XenbusStateReconfiguring:
1150                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1151                 xenbus_switch_state(dev, XenbusStateReconfigured);
1152
1153                 break;
1154
1155         default:
1156                 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1157                                         frontend_state);
1158                 break;
1159         }
1160 }
1161
1162 /*
1163   Release the translation entry specfied
1164 */
1165 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1166 {
1167         struct v2p_entry *entry, *tmp;
1168         struct list_head *head = &(info->v2p_entry_lists);
1169         unsigned long flags;
1170
1171         spin_lock_irqsave(&info->v2p_lock, flags);
1172
1173         list_for_each_entry_safe(entry, tmp, head, l)
1174                 __scsiback_del_translation_entry(entry);
1175
1176         spin_unlock_irqrestore(&info->v2p_lock, flags);
1177 }
1178
1179 static int scsiback_remove(struct xenbus_device *dev)
1180 {
1181         struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1182
1183         if (info->irq)
1184                 scsiback_disconnect(info);
1185
1186         scsiback_release_translation_entry(info);
1187
1188         dev_set_drvdata(&dev->dev, NULL);
1189
1190         return 0;
1191 }
1192
1193 static int scsiback_probe(struct xenbus_device *dev,
1194                            const struct xenbus_device_id *id)
1195 {
1196         int err;
1197
1198         struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1199                                             GFP_KERNEL);
1200
1201         DPRINTK("%p %d\n", dev, dev->otherend_id);
1202
1203         if (!info) {
1204                 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1205                 return -ENOMEM;
1206         }
1207         info->dev = dev;
1208         dev_set_drvdata(&dev->dev, info);
1209
1210         info->domid = dev->otherend_id;
1211         spin_lock_init(&info->ring_lock);
1212         info->ring_error = 0;
1213         atomic_set(&info->nr_unreplied_reqs, 0);
1214         init_waitqueue_head(&info->waiting_to_free);
1215         info->dev = dev;
1216         info->irq = 0;
1217         INIT_LIST_HEAD(&info->v2p_entry_lists);
1218         spin_lock_init(&info->v2p_lock);
1219
1220         err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1221                             SG_ALL);
1222         if (err)
1223                 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1224
1225         err = xenbus_switch_state(dev, XenbusStateInitWait);
1226         if (err)
1227                 goto fail;
1228
1229         return 0;
1230
1231 fail:
1232         pr_warn("xen-pvscsi: %s failed\n", __func__);
1233         scsiback_remove(dev);
1234
1235         return err;
1236 }
1237
1238 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1239 {
1240         switch (tport->tport_proto_id) {
1241         case SCSI_PROTOCOL_SAS:
1242                 return "SAS";
1243         case SCSI_PROTOCOL_FCP:
1244                 return "FCP";
1245         case SCSI_PROTOCOL_ISCSI:
1246                 return "iSCSI";
1247         default:
1248                 break;
1249         }
1250
1251         return "Unknown";
1252 }
1253
1254 static u8 scsiback_get_fabric_proto_ident(struct se_portal_group *se_tpg)
1255 {
1256         struct scsiback_tpg *tpg = container_of(se_tpg,
1257                                 struct scsiback_tpg, se_tpg);
1258         struct scsiback_tport *tport = tpg->tport;
1259
1260         switch (tport->tport_proto_id) {
1261         case SCSI_PROTOCOL_SAS:
1262                 return sas_get_fabric_proto_ident(se_tpg);
1263         case SCSI_PROTOCOL_FCP:
1264                 return fc_get_fabric_proto_ident(se_tpg);
1265         case SCSI_PROTOCOL_ISCSI:
1266                 return iscsi_get_fabric_proto_ident(se_tpg);
1267         default:
1268                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1269                         tport->tport_proto_id);
1270                 break;
1271         }
1272
1273         return sas_get_fabric_proto_ident(se_tpg);
1274 }
1275
1276 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1277 {
1278         struct scsiback_tpg *tpg = container_of(se_tpg,
1279                                 struct scsiback_tpg, se_tpg);
1280         struct scsiback_tport *tport = tpg->tport;
1281
1282         return &tport->tport_name[0];
1283 }
1284
1285 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1286 {
1287         struct scsiback_tpg *tpg = container_of(se_tpg,
1288                                 struct scsiback_tpg, se_tpg);
1289         return tpg->tport_tpgt;
1290 }
1291
1292 static u32 scsiback_get_default_depth(struct se_portal_group *se_tpg)
1293 {
1294         return 1;
1295 }
1296
1297 static u32
1298 scsiback_get_pr_transport_id(struct se_portal_group *se_tpg,
1299                               struct se_node_acl *se_nacl,
1300                               struct t10_pr_registration *pr_reg,
1301                               int *format_code,
1302                               unsigned char *buf)
1303 {
1304         struct scsiback_tpg *tpg = container_of(se_tpg,
1305                                 struct scsiback_tpg, se_tpg);
1306         struct scsiback_tport *tport = tpg->tport;
1307
1308         switch (tport->tport_proto_id) {
1309         case SCSI_PROTOCOL_SAS:
1310                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1311                                         format_code, buf);
1312         case SCSI_PROTOCOL_FCP:
1313                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1314                                         format_code, buf);
1315         case SCSI_PROTOCOL_ISCSI:
1316                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1317                                         format_code, buf);
1318         default:
1319                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1320                         tport->tport_proto_id);
1321                 break;
1322         }
1323
1324         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1325                         format_code, buf);
1326 }
1327
1328 static u32
1329 scsiback_get_pr_transport_id_len(struct se_portal_group *se_tpg,
1330                                   struct se_node_acl *se_nacl,
1331                                   struct t10_pr_registration *pr_reg,
1332                                   int *format_code)
1333 {
1334         struct scsiback_tpg *tpg = container_of(se_tpg,
1335                                 struct scsiback_tpg, se_tpg);
1336         struct scsiback_tport *tport = tpg->tport;
1337
1338         switch (tport->tport_proto_id) {
1339         case SCSI_PROTOCOL_SAS:
1340                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1341                                         format_code);
1342         case SCSI_PROTOCOL_FCP:
1343                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1344                                         format_code);
1345         case SCSI_PROTOCOL_ISCSI:
1346                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1347                                         format_code);
1348         default:
1349                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1350                         tport->tport_proto_id);
1351                 break;
1352         }
1353
1354         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1355                         format_code);
1356 }
1357
1358 static char *
1359 scsiback_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
1360                                     const char *buf,
1361                                     u32 *out_tid_len,
1362                                     char **port_nexus_ptr)
1363 {
1364         struct scsiback_tpg *tpg = container_of(se_tpg,
1365                                 struct scsiback_tpg, se_tpg);
1366         struct scsiback_tport *tport = tpg->tport;
1367
1368         switch (tport->tport_proto_id) {
1369         case SCSI_PROTOCOL_SAS:
1370                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1371                                         port_nexus_ptr);
1372         case SCSI_PROTOCOL_FCP:
1373                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1374                                         port_nexus_ptr);
1375         case SCSI_PROTOCOL_ISCSI:
1376                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1377                                         port_nexus_ptr);
1378         default:
1379                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1380                         tport->tport_proto_id);
1381                 break;
1382         }
1383
1384         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1385                         port_nexus_ptr);
1386 }
1387
1388 static struct se_wwn *
1389 scsiback_make_tport(struct target_fabric_configfs *tf,
1390                      struct config_group *group,
1391                      const char *name)
1392 {
1393         struct scsiback_tport *tport;
1394         char *ptr;
1395         u64 wwpn = 0;
1396         int off = 0;
1397
1398         tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1399         if (!tport)
1400                 return ERR_PTR(-ENOMEM);
1401
1402         tport->tport_wwpn = wwpn;
1403         /*
1404          * Determine the emulated Protocol Identifier and Target Port Name
1405          * based on the incoming configfs directory name.
1406          */
1407         ptr = strstr(name, "naa.");
1408         if (ptr) {
1409                 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1410                 goto check_len;
1411         }
1412         ptr = strstr(name, "fc.");
1413         if (ptr) {
1414                 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1415                 off = 3; /* Skip over "fc." */
1416                 goto check_len;
1417         }
1418         ptr = strstr(name, "iqn.");
1419         if (ptr) {
1420                 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1421                 goto check_len;
1422         }
1423
1424         pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1425         kfree(tport);
1426         return ERR_PTR(-EINVAL);
1427
1428 check_len:
1429         if (strlen(name) >= VSCSI_NAMELEN) {
1430                 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1431                         scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1432                 kfree(tport);
1433                 return ERR_PTR(-EINVAL);
1434         }
1435         snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1436
1437         pr_debug("xen-pvscsi: Allocated emulated Target %s Address: %s\n",
1438                  scsiback_dump_proto_id(tport), name);
1439
1440         return &tport->tport_wwn;
1441 }
1442
1443 static void scsiback_drop_tport(struct se_wwn *wwn)
1444 {
1445         struct scsiback_tport *tport = container_of(wwn,
1446                                 struct scsiback_tport, tport_wwn);
1447
1448         pr_debug("xen-pvscsi: Deallocating emulated Target %s Address: %s\n",
1449                  scsiback_dump_proto_id(tport), tport->tport_name);
1450
1451         kfree(tport);
1452 }
1453
1454 static struct se_node_acl *
1455 scsiback_alloc_fabric_acl(struct se_portal_group *se_tpg)
1456 {
1457         return kzalloc(sizeof(struct se_node_acl), GFP_KERNEL);
1458 }
1459
1460 static void
1461 scsiback_release_fabric_acl(struct se_portal_group *se_tpg,
1462                              struct se_node_acl *se_nacl)
1463 {
1464         kfree(se_nacl);
1465 }
1466
1467 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1468 {
1469         return 1;
1470 }
1471
1472 static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1473 {
1474         /*
1475          * Do not release struct se_cmd's containing a valid TMR
1476          * pointer.  These will be released directly in scsiback_device_action()
1477          * with transport_generic_free_cmd().
1478          */
1479         if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1480                 return 0;
1481
1482         transport_generic_free_cmd(se_cmd, 0);
1483         return 1;
1484 }
1485
1486 static void scsiback_release_cmd(struct se_cmd *se_cmd)
1487 {
1488         struct vscsibk_pend *pending_req = container_of(se_cmd,
1489                                 struct vscsibk_pend, se_cmd);
1490
1491         kmem_cache_free(scsiback_cachep, pending_req);
1492 }
1493
1494 static int scsiback_shutdown_session(struct se_session *se_sess)
1495 {
1496         return 0;
1497 }
1498
1499 static void scsiback_close_session(struct se_session *se_sess)
1500 {
1501 }
1502
1503 static u32 scsiback_sess_get_index(struct se_session *se_sess)
1504 {
1505         return 0;
1506 }
1507
1508 static int scsiback_write_pending(struct se_cmd *se_cmd)
1509 {
1510         /* Go ahead and process the write immediately */
1511         target_execute_cmd(se_cmd);
1512
1513         return 0;
1514 }
1515
1516 static int scsiback_write_pending_status(struct se_cmd *se_cmd)
1517 {
1518         return 0;
1519 }
1520
1521 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1522 {
1523 }
1524
1525 static u32 scsiback_get_task_tag(struct se_cmd *se_cmd)
1526 {
1527         struct vscsibk_pend *pending_req = container_of(se_cmd,
1528                                 struct vscsibk_pend, se_cmd);
1529
1530         return pending_req->rqid;
1531 }
1532
1533 static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1534 {
1535         return 0;
1536 }
1537
1538 static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1539 {
1540         struct vscsibk_pend *pending_req = container_of(se_cmd,
1541                                 struct vscsibk_pend, se_cmd);
1542
1543         pending_req->result = SAM_STAT_GOOD;
1544         scsiback_cmd_done(pending_req);
1545         return 0;
1546 }
1547
1548 static int scsiback_queue_status(struct se_cmd *se_cmd)
1549 {
1550         struct vscsibk_pend *pending_req = container_of(se_cmd,
1551                                 struct vscsibk_pend, se_cmd);
1552
1553         if (se_cmd->sense_buffer &&
1554             ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1555              (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1556                 pending_req->result = (DRIVER_SENSE << 24) |
1557                                       SAM_STAT_CHECK_CONDITION;
1558         else
1559                 pending_req->result = se_cmd->scsi_status;
1560
1561         scsiback_cmd_done(pending_req);
1562         return 0;
1563 }
1564
1565 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1566 {
1567         struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
1568         struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr;
1569
1570         atomic_set(&tmr->tmr_complete, 1);
1571         wake_up(&tmr->tmr_wait);
1572 }
1573
1574 static void scsiback_aborted_task(struct se_cmd *se_cmd)
1575 {
1576 }
1577
1578 static ssize_t scsiback_tpg_param_show_alias(struct se_portal_group *se_tpg,
1579                                              char *page)
1580 {
1581         struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1582                                                 se_tpg);
1583         ssize_t rb;
1584
1585         mutex_lock(&tpg->tv_tpg_mutex);
1586         rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1587         mutex_unlock(&tpg->tv_tpg_mutex);
1588
1589         return rb;
1590 }
1591
1592 static ssize_t scsiback_tpg_param_store_alias(struct se_portal_group *se_tpg,
1593                                               const char *page, size_t count)
1594 {
1595         struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1596                                                 se_tpg);
1597         int len;
1598
1599         if (strlen(page) >= VSCSI_NAMELEN) {
1600                 pr_err("param alias: %s, exceeds max: %d\n", page,
1601                         VSCSI_NAMELEN);
1602                 return -EINVAL;
1603         }
1604
1605         mutex_lock(&tpg->tv_tpg_mutex);
1606         len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1607         if (tpg->param_alias[len - 1] == '\n')
1608                 tpg->param_alias[len - 1] = '\0';
1609         mutex_unlock(&tpg->tv_tpg_mutex);
1610
1611         return count;
1612 }
1613
1614 TF_TPG_PARAM_ATTR(scsiback, alias, S_IRUGO | S_IWUSR);
1615
1616 static struct configfs_attribute *scsiback_param_attrs[] = {
1617         &scsiback_tpg_param_alias.attr,
1618         NULL,
1619 };
1620
1621 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1622                                 const char *name)
1623 {
1624         struct se_portal_group *se_tpg;
1625         struct se_session *se_sess;
1626         struct scsiback_nexus *tv_nexus;
1627
1628         mutex_lock(&tpg->tv_tpg_mutex);
1629         if (tpg->tpg_nexus) {
1630                 mutex_unlock(&tpg->tv_tpg_mutex);
1631                 pr_debug("tpg->tpg_nexus already exists\n");
1632                 return -EEXIST;
1633         }
1634         se_tpg = &tpg->se_tpg;
1635
1636         tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1637         if (!tv_nexus) {
1638                 mutex_unlock(&tpg->tv_tpg_mutex);
1639                 return -ENOMEM;
1640         }
1641         /*
1642          *  Initialize the struct se_session pointer
1643          */
1644         tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_NORMAL);
1645         if (IS_ERR(tv_nexus->tvn_se_sess)) {
1646                 mutex_unlock(&tpg->tv_tpg_mutex);
1647                 kfree(tv_nexus);
1648                 return -ENOMEM;
1649         }
1650         se_sess = tv_nexus->tvn_se_sess;
1651         /*
1652          * Since we are running in 'demo mode' this call with generate a
1653          * struct se_node_acl for the scsiback struct se_portal_group with
1654          * the SCSI Initiator port name of the passed configfs group 'name'.
1655          */
1656         tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1657                                 se_tpg, (unsigned char *)name);
1658         if (!tv_nexus->tvn_se_sess->se_node_acl) {
1659                 mutex_unlock(&tpg->tv_tpg_mutex);
1660                 pr_debug("core_tpg_check_initiator_node_acl() failed for %s\n",
1661                          name);
1662                 goto out;
1663         }
1664         /*
1665          * Now register the TCM pvscsi virtual I_T Nexus as active with the
1666          * call to __transport_register_session()
1667          */
1668         __transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
1669                         tv_nexus->tvn_se_sess, tv_nexus);
1670         tpg->tpg_nexus = tv_nexus;
1671
1672         mutex_unlock(&tpg->tv_tpg_mutex);
1673         return 0;
1674
1675 out:
1676         transport_free_session(se_sess);
1677         kfree(tv_nexus);
1678         return -ENOMEM;
1679 }
1680
1681 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1682 {
1683         struct se_session *se_sess;
1684         struct scsiback_nexus *tv_nexus;
1685
1686         mutex_lock(&tpg->tv_tpg_mutex);
1687         tv_nexus = tpg->tpg_nexus;
1688         if (!tv_nexus) {
1689                 mutex_unlock(&tpg->tv_tpg_mutex);
1690                 return -ENODEV;
1691         }
1692
1693         se_sess = tv_nexus->tvn_se_sess;
1694         if (!se_sess) {
1695                 mutex_unlock(&tpg->tv_tpg_mutex);
1696                 return -ENODEV;
1697         }
1698
1699         if (tpg->tv_tpg_port_count != 0) {
1700                 mutex_unlock(&tpg->tv_tpg_mutex);
1701                 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1702                         tpg->tv_tpg_port_count);
1703                 return -EBUSY;
1704         }
1705
1706         if (tpg->tv_tpg_fe_count != 0) {
1707                 mutex_unlock(&tpg->tv_tpg_mutex);
1708                 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1709                         tpg->tv_tpg_fe_count);
1710                 return -EBUSY;
1711         }
1712
1713         pr_debug("xen-pvscsi: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1714                 scsiback_dump_proto_id(tpg->tport),
1715                 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1716
1717         /*
1718          * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1719          */
1720         transport_deregister_session(tv_nexus->tvn_se_sess);
1721         tpg->tpg_nexus = NULL;
1722         mutex_unlock(&tpg->tv_tpg_mutex);
1723
1724         kfree(tv_nexus);
1725         return 0;
1726 }
1727
1728 static ssize_t scsiback_tpg_show_nexus(struct se_portal_group *se_tpg,
1729                                         char *page)
1730 {
1731         struct scsiback_tpg *tpg = container_of(se_tpg,
1732                                 struct scsiback_tpg, se_tpg);
1733         struct scsiback_nexus *tv_nexus;
1734         ssize_t ret;
1735
1736         mutex_lock(&tpg->tv_tpg_mutex);
1737         tv_nexus = tpg->tpg_nexus;
1738         if (!tv_nexus) {
1739                 mutex_unlock(&tpg->tv_tpg_mutex);
1740                 return -ENODEV;
1741         }
1742         ret = snprintf(page, PAGE_SIZE, "%s\n",
1743                         tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1744         mutex_unlock(&tpg->tv_tpg_mutex);
1745
1746         return ret;
1747 }
1748
1749 static ssize_t scsiback_tpg_store_nexus(struct se_portal_group *se_tpg,
1750                                          const char *page,
1751                                          size_t count)
1752 {
1753         struct scsiback_tpg *tpg = container_of(se_tpg,
1754                                 struct scsiback_tpg, se_tpg);
1755         struct scsiback_tport *tport_wwn = tpg->tport;
1756         unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1757         int ret;
1758         /*
1759          * Shutdown the active I_T nexus if 'NULL' is passed..
1760          */
1761         if (!strncmp(page, "NULL", 4)) {
1762                 ret = scsiback_drop_nexus(tpg);
1763                 return (!ret) ? count : ret;
1764         }
1765         /*
1766          * Otherwise make sure the passed virtual Initiator port WWN matches
1767          * the fabric protocol_id set in scsiback_make_tport(), and call
1768          * scsiback_make_nexus().
1769          */
1770         if (strlen(page) >= VSCSI_NAMELEN) {
1771                 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1772                         page, VSCSI_NAMELEN);
1773                 return -EINVAL;
1774         }
1775         snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1776
1777         ptr = strstr(i_port, "naa.");
1778         if (ptr) {
1779                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1780                         pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1781                                 i_port, scsiback_dump_proto_id(tport_wwn));
1782                         return -EINVAL;
1783                 }
1784                 port_ptr = &i_port[0];
1785                 goto check_newline;
1786         }
1787         ptr = strstr(i_port, "fc.");
1788         if (ptr) {
1789                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1790                         pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1791                                 i_port, scsiback_dump_proto_id(tport_wwn));
1792                         return -EINVAL;
1793                 }
1794                 port_ptr = &i_port[3]; /* Skip over "fc." */
1795                 goto check_newline;
1796         }
1797         ptr = strstr(i_port, "iqn.");
1798         if (ptr) {
1799                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1800                         pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1801                                 i_port, scsiback_dump_proto_id(tport_wwn));
1802                         return -EINVAL;
1803                 }
1804                 port_ptr = &i_port[0];
1805                 goto check_newline;
1806         }
1807         pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1808                 i_port);
1809         return -EINVAL;
1810         /*
1811          * Clear any trailing newline for the NAA WWN
1812          */
1813 check_newline:
1814         if (i_port[strlen(i_port) - 1] == '\n')
1815                 i_port[strlen(i_port) - 1] = '\0';
1816
1817         ret = scsiback_make_nexus(tpg, port_ptr);
1818         if (ret < 0)
1819                 return ret;
1820
1821         return count;
1822 }
1823
1824 TF_TPG_BASE_ATTR(scsiback, nexus, S_IRUGO | S_IWUSR);
1825
1826 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1827         &scsiback_tpg_nexus.attr,
1828         NULL,
1829 };
1830
1831 static ssize_t
1832 scsiback_wwn_show_attr_version(struct target_fabric_configfs *tf,
1833                                 char *page)
1834 {
1835         return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1836                 UTS_RELEASE"\n",
1837                 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1838 }
1839
1840 TF_WWN_ATTR_RO(scsiback, version);
1841
1842 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1843         &scsiback_wwn_version.attr,
1844         NULL,
1845 };
1846
1847 static char *scsiback_get_fabric_name(void)
1848 {
1849         return "xen-pvscsi";
1850 }
1851
1852 static int scsiback_port_link(struct se_portal_group *se_tpg,
1853                                struct se_lun *lun)
1854 {
1855         struct scsiback_tpg *tpg = container_of(se_tpg,
1856                                 struct scsiback_tpg, se_tpg);
1857
1858         mutex_lock(&tpg->tv_tpg_mutex);
1859         tpg->tv_tpg_port_count++;
1860         mutex_unlock(&tpg->tv_tpg_mutex);
1861
1862         return 0;
1863 }
1864
1865 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1866                                   struct se_lun *lun)
1867 {
1868         struct scsiback_tpg *tpg = container_of(se_tpg,
1869                                 struct scsiback_tpg, se_tpg);
1870
1871         mutex_lock(&tpg->tv_tpg_mutex);
1872         tpg->tv_tpg_port_count--;
1873         mutex_unlock(&tpg->tv_tpg_mutex);
1874 }
1875
1876 static struct se_portal_group *
1877 scsiback_make_tpg(struct se_wwn *wwn,
1878                    struct config_group *group,
1879                    const char *name)
1880 {
1881         struct scsiback_tport *tport = container_of(wwn,
1882                         struct scsiback_tport, tport_wwn);
1883
1884         struct scsiback_tpg *tpg;
1885         u16 tpgt;
1886         int ret;
1887
1888         if (strstr(name, "tpgt_") != name)
1889                 return ERR_PTR(-EINVAL);
1890         ret = kstrtou16(name + 5, 10, &tpgt);
1891         if (ret)
1892                 return ERR_PTR(ret);
1893
1894         tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1895         if (!tpg)
1896                 return ERR_PTR(-ENOMEM);
1897
1898         mutex_init(&tpg->tv_tpg_mutex);
1899         INIT_LIST_HEAD(&tpg->tv_tpg_list);
1900         INIT_LIST_HEAD(&tpg->info_list);
1901         tpg->tport = tport;
1902         tpg->tport_tpgt = tpgt;
1903
1904         ret = core_tpg_register(&scsiback_fabric_configfs->tf_ops, wwn,
1905                                 &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
1906         if (ret < 0) {
1907                 kfree(tpg);
1908                 return NULL;
1909         }
1910         mutex_lock(&scsiback_mutex);
1911         list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1912         mutex_unlock(&scsiback_mutex);
1913
1914         return &tpg->se_tpg;
1915 }
1916
1917 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1918 {
1919         struct scsiback_tpg *tpg = container_of(se_tpg,
1920                                 struct scsiback_tpg, se_tpg);
1921
1922         mutex_lock(&scsiback_mutex);
1923         list_del(&tpg->tv_tpg_list);
1924         mutex_unlock(&scsiback_mutex);
1925         /*
1926          * Release the virtual I_T Nexus for this xen-pvscsi TPG
1927          */
1928         scsiback_drop_nexus(tpg);
1929         /*
1930          * Deregister the se_tpg from TCM..
1931          */
1932         core_tpg_deregister(se_tpg);
1933         kfree(tpg);
1934 }
1935
1936 static int scsiback_check_true(struct se_portal_group *se_tpg)
1937 {
1938         return 1;
1939 }
1940
1941 static int scsiback_check_false(struct se_portal_group *se_tpg)
1942 {
1943         return 0;
1944 }
1945
1946 static struct target_core_fabric_ops scsiback_ops = {
1947         .get_fabric_name                = scsiback_get_fabric_name,
1948         .get_fabric_proto_ident         = scsiback_get_fabric_proto_ident,
1949         .tpg_get_wwn                    = scsiback_get_fabric_wwn,
1950         .tpg_get_tag                    = scsiback_get_tag,
1951         .tpg_get_default_depth          = scsiback_get_default_depth,
1952         .tpg_get_pr_transport_id        = scsiback_get_pr_transport_id,
1953         .tpg_get_pr_transport_id_len    = scsiback_get_pr_transport_id_len,
1954         .tpg_parse_pr_out_transport_id  = scsiback_parse_pr_out_transport_id,
1955         .tpg_check_demo_mode            = scsiback_check_true,
1956         .tpg_check_demo_mode_cache      = scsiback_check_true,
1957         .tpg_check_demo_mode_write_protect = scsiback_check_false,
1958         .tpg_check_prod_mode_write_protect = scsiback_check_false,
1959         .tpg_alloc_fabric_acl           = scsiback_alloc_fabric_acl,
1960         .tpg_release_fabric_acl         = scsiback_release_fabric_acl,
1961         .tpg_get_inst_index             = scsiback_tpg_get_inst_index,
1962         .check_stop_free                = scsiback_check_stop_free,
1963         .release_cmd                    = scsiback_release_cmd,
1964         .put_session                    = NULL,
1965         .shutdown_session               = scsiback_shutdown_session,
1966         .close_session                  = scsiback_close_session,
1967         .sess_get_index                 = scsiback_sess_get_index,
1968         .sess_get_initiator_sid         = NULL,
1969         .write_pending                  = scsiback_write_pending,
1970         .write_pending_status           = scsiback_write_pending_status,
1971         .set_default_node_attributes    = scsiback_set_default_node_attrs,
1972         .get_task_tag                   = scsiback_get_task_tag,
1973         .get_cmd_state                  = scsiback_get_cmd_state,
1974         .queue_data_in                  = scsiback_queue_data_in,
1975         .queue_status                   = scsiback_queue_status,
1976         .queue_tm_rsp                   = scsiback_queue_tm_rsp,
1977         .aborted_task                   = scsiback_aborted_task,
1978         /*
1979          * Setup callers for generic logic in target_core_fabric_configfs.c
1980          */
1981         .fabric_make_wwn                = scsiback_make_tport,
1982         .fabric_drop_wwn                = scsiback_drop_tport,
1983         .fabric_make_tpg                = scsiback_make_tpg,
1984         .fabric_drop_tpg                = scsiback_drop_tpg,
1985         .fabric_post_link               = scsiback_port_link,
1986         .fabric_pre_unlink              = scsiback_port_unlink,
1987         .fabric_make_np                 = NULL,
1988         .fabric_drop_np                 = NULL,
1989 #if 0
1990         .fabric_make_nodeacl            = scsiback_make_nodeacl,
1991         .fabric_drop_nodeacl            = scsiback_drop_nodeacl,
1992 #endif
1993 };
1994
1995 static int scsiback_register_configfs(void)
1996 {
1997         struct target_fabric_configfs *fabric;
1998         int ret;
1999
2000         pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
2001                  VSCSI_VERSION, utsname()->sysname, utsname()->machine);
2002         /*
2003          * Register the top level struct config_item_type with TCM core
2004          */
2005         fabric = target_fabric_configfs_init(THIS_MODULE, "xen-pvscsi");
2006         if (IS_ERR(fabric))
2007                 return PTR_ERR(fabric);
2008
2009         /*
2010          * Setup fabric->tf_ops from our local scsiback_ops
2011          */
2012         fabric->tf_ops = scsiback_ops;
2013         /*
2014          * Setup default attribute lists for various fabric->tf_cit_tmpl
2015          */
2016         fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = scsiback_wwn_attrs;
2017         fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = scsiback_tpg_attrs;
2018         fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
2019         fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = scsiback_param_attrs;
2020         fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
2021         fabric->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
2022         fabric->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
2023         fabric->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
2024         fabric->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
2025         /*
2026          * Register the fabric for use within TCM
2027          */
2028         ret = target_fabric_configfs_register(fabric);
2029         if (ret < 0) {
2030                 target_fabric_configfs_free(fabric);
2031                 return ret;
2032         }
2033         /*
2034          * Setup our local pointer to *fabric
2035          */
2036         scsiback_fabric_configfs = fabric;
2037         pr_debug("xen-pvscsi: Set fabric -> scsiback_fabric_configfs\n");
2038         return 0;
2039 };
2040
2041 static void scsiback_deregister_configfs(void)
2042 {
2043         if (!scsiback_fabric_configfs)
2044                 return;
2045
2046         target_fabric_configfs_deregister(scsiback_fabric_configfs);
2047         scsiback_fabric_configfs = NULL;
2048         pr_debug("xen-pvscsi: Cleared scsiback_fabric_configfs\n");
2049 };
2050
2051 static const struct xenbus_device_id scsiback_ids[] = {
2052         { "vscsi" },
2053         { "" }
2054 };
2055
2056 static struct xenbus_driver scsiback_driver = {
2057         .ids                    = scsiback_ids,
2058         .probe                  = scsiback_probe,
2059         .remove                 = scsiback_remove,
2060         .otherend_changed       = scsiback_frontend_changed
2061 };
2062
2063 static void scsiback_init_pend(void *p)
2064 {
2065         struct vscsibk_pend *pend = p;
2066         int i;
2067
2068         memset(pend, 0, sizeof(*pend));
2069         for (i = 0; i < VSCSI_MAX_GRANTS; i++)
2070                 pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
2071 }
2072
2073 static int __init scsiback_init(void)
2074 {
2075         int ret;
2076
2077         if (!xen_domain())
2078                 return -ENODEV;
2079
2080         scsiback_cachep = kmem_cache_create("vscsiif_cache",
2081                 sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
2082         if (!scsiback_cachep)
2083                 return -ENOMEM;
2084
2085         ret = xenbus_register_backend(&scsiback_driver);
2086         if (ret)
2087                 goto out_cache_destroy;
2088
2089         ret = scsiback_register_configfs();
2090         if (ret)
2091                 goto out_unregister_xenbus;
2092
2093         return 0;
2094
2095 out_unregister_xenbus:
2096         xenbus_unregister_driver(&scsiback_driver);
2097 out_cache_destroy:
2098         kmem_cache_destroy(scsiback_cachep);
2099         pr_err("xen-pvscsi: %s: error %d\n", __func__, ret);
2100         return ret;
2101 }
2102
2103 static void __exit scsiback_exit(void)
2104 {
2105         struct page *page;
2106
2107         while (free_pages_num) {
2108                 if (get_free_page(&page))
2109                         BUG();
2110                 gnttab_free_pages(1, &page);
2111         }
2112         scsiback_deregister_configfs();
2113         xenbus_unregister_driver(&scsiback_driver);
2114         kmem_cache_destroy(scsiback_cachep);
2115 }
2116
2117 module_init(scsiback_init);
2118 module_exit(scsiback_exit);
2119
2120 MODULE_DESCRIPTION("Xen SCSI backend driver");
2121 MODULE_LICENSE("Dual BSD/GPL");
2122 MODULE_ALIAS("xen-backend:vscsi");
2123 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");