drivers/xen/xen-scsiback.c

   1 /*
   2  * Xen SCSI backend driver
   3  *
   4  * Copyright (c) 2008, FUJITSU Limited
   5  *
   6  * Based on the blkback driver code.
   7  * Adaption to kernel taget core infrastructure taken from vhost/scsi.c
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License version 2
  11  * as published by the Free Software Foundation; or, when distributed
  12  * separately from the Linux kernel or incorporated into other
  13  * software packages, subject to the following license:
  14  *
  15  * Permission is hereby granted, free of charge, to any person obtaining a copy
  16  * of this source file (the "Software"), to deal in the Software without
  17  * restriction, including without limitation the rights to use, copy, modify,
  18  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
  19  * and to permit persons to whom the Software is furnished to do so, subject to
  20  * the following conditions:
  21  *
  22  * The above copyright notice and this permission notice shall be included in
  23  * all copies or substantial portions of the Software.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  28  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  29  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  30  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  31  * IN THE SOFTWARE.
  32  */
  33
  34 #include <stdarg.h>
  35
  36 #include <linux/module.h>
  37 #include <linux/utsname.h>
  38 #include <linux/interrupt.h>
  39 #include <linux/slab.h>
  40 #include <linux/wait.h>
  41 #include <linux/sched.h>
  42 #include <linux/list.h>
  43 #include <linux/gfp.h>
  44 #include <linux/delay.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/configfs.h>
  47
  48 #include <generated/utsrelease.h>
  49
  50 #include <scsi/scsi_dbg.h>
  51 #include <scsi/scsi_eh.h>
  52 #include <scsi/scsi_tcq.h>
  53
  54 #include <target/target_core_base.h>
  55 #include <target/target_core_fabric.h>
  56 #include <target/target_core_configfs.h>
  57 #include <target/target_core_fabric_configfs.h>
  58
  59 #include <asm/hypervisor.h>
  60
  61 #include <xen/xen.h>
  62 #include <xen/balloon.h>
  63 #include <xen/events.h>
  64 #include <xen/xenbus.h>
  65 #include <xen/grant_table.h>
  66 #include <xen/page.h>
  67
  68 #include <xen/interface/grant_table.h>
  69 #include <xen/interface/io/vscsiif.h>
  70
  71 #define DPRINTK(_f, _a...)                      \
  72         pr_debug("(file=%s, line=%d) " _f, __FILE__ , __LINE__ , ## _a)
  73
  74 #define VSCSI_VERSION   "v0.1"
  75 #define VSCSI_NAMELEN   32
  76
  77 struct ids_tuple {
  78         unsigned int hst;               /* host    */
  79         unsigned int chn;               /* channel */
  80         unsigned int tgt;               /* target  */
  81         unsigned int lun;               /* LUN     */
  82 };
  83
  84 struct v2p_entry {
  85         struct ids_tuple v;             /* translate from */
  86         struct scsiback_tpg *tpg;       /* translate to   */
  87         unsigned int lun;
  88         struct kref kref;
  89         struct list_head l;
  90 };
  91
  92 struct vscsibk_info {
  93         struct xenbus_device *dev;
  94
  95         domid_t domid;
  96         unsigned int irq;
  97
  98         struct vscsiif_back_ring ring;
  99         int ring_error;
 100
 101         spinlock_t ring_lock;
 102         atomic_t nr_unreplied_reqs;
 103
 104         spinlock_t v2p_lock;
 105         struct list_head v2p_entry_lists;
 106
 107         wait_queue_head_t waiting_to_free;
 108 };
 109
 110 /* theoretical maximum of grants for one request */
 111 #define VSCSI_MAX_GRANTS        (SG_ALL + VSCSIIF_SG_TABLESIZE)
 112
 113 /*
 114  * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
 115  * call to map/unmap grants. Don't choose it too large, as there are arrays
 116  * with VSCSI_GRANT_BATCH elements allocated on the stack.
 117  */
 118 #define VSCSI_GRANT_BATCH       16
 119
 120 struct vscsibk_pend {
 121         uint16_t rqid;
 122
 123         uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
 124         uint8_t cmd_len;
 125
 126         uint8_t sc_data_direction;
 127         uint16_t n_sg;          /* real length of SG list */
 128         uint16_t n_grants;      /* SG pages and potentially SG list */
 129         uint32_t data_len;
 130         uint32_t result;
 131
 132         struct vscsibk_info *info;
 133         struct v2p_entry *v2p;
 134         struct scatterlist *sgl;
 135
 136         uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
 137
 138         grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
 139         struct page *pages[VSCSI_MAX_GRANTS];
 140
 141         struct se_cmd se_cmd;
 142 };
 143
 144 struct scsiback_tmr {
 145         atomic_t tmr_complete;
 146         wait_queue_head_t tmr_wait;
 147 };
 148
 149 struct scsiback_nexus {
 150         /* Pointer to TCM session for I_T Nexus */
 151         struct se_session *tvn_se_sess;
 152 };
 153
 154 struct scsiback_tport {
 155         /* SCSI protocol the tport is providing */
 156         u8 tport_proto_id;
 157         /* Binary World Wide unique Port Name for pvscsi Target port */
 158         u64 tport_wwpn;
 159         /* ASCII formatted WWPN for pvscsi Target port */
 160         char tport_name[VSCSI_NAMELEN];
 161         /* Returned by scsiback_make_tport() */
 162         struct se_wwn tport_wwn;
 163 };
 164
 165 struct scsiback_tpg {
 166         /* scsiback port target portal group tag for TCM */
 167         u16 tport_tpgt;
 168         /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
 169         int tv_tpg_port_count;
 170         /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
 171         int tv_tpg_fe_count;
 172         /* list for scsiback_list */
 173         struct list_head tv_tpg_list;
 174         /* Used to protect access for tpg_nexus */
 175         struct mutex tv_tpg_mutex;
 176         /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
 177         struct scsiback_nexus *tpg_nexus;
 178         /* Pointer back to scsiback_tport */
 179         struct scsiback_tport *tport;
 180         /* Returned by scsiback_make_tpg() */
 181         struct se_portal_group se_tpg;
 182         /* alias used in xenstore */
 183         char param_alias[VSCSI_NAMELEN];
 184         /* list of info structures related to this target portal group */
 185         struct list_head info_list;
 186 };
 187
 188 #define SCSIBACK_INVALID_HANDLE (~0)
 189
 190 static bool log_print_stat;
 191 module_param(log_print_stat, bool, 0644);
 192
 193 static int scsiback_max_buffer_pages = 1024;
 194 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
 195 MODULE_PARM_DESC(max_buffer_pages,
 196 "Maximum number of free pages to keep in backend buffer");
 197
 198 static struct kmem_cache *scsiback_cachep;
 199 static DEFINE_SPINLOCK(free_pages_lock);
 200 static int free_pages_num;
 201 static LIST_HEAD(scsiback_free_pages);
 202
 203 /* Global spinlock to protect scsiback TPG list */
 204 static DEFINE_MUTEX(scsiback_mutex);
 205 static LIST_HEAD(scsiback_list);
 206
 207 /* Local pointer to allocated TCM configfs fabric module */
 208 static struct target_fabric_configfs *scsiback_fabric_configfs;
 209
 210 static void scsiback_get(struct vscsibk_info *info)
 211 {
 212         atomic_inc(&info->nr_unreplied_reqs);
 213 }
 214
 215 static void scsiback_put(struct vscsibk_info *info)
 216 {
 217         if (atomic_dec_and_test(&info->nr_unreplied_reqs))
 218                 wake_up(&info->waiting_to_free);
 219 }
 220
 221 static void put_free_pages(struct page **page, int num)
 222 {
 223         unsigned long flags;
 224         int i = free_pages_num + num, n = num;
 225
 226         if (num == 0)
 227                 return;
 228         if (i > scsiback_max_buffer_pages) {
 229                 n = min(num, i - scsiback_max_buffer_pages);
 230                 free_xenballooned_pages(n, page + num - n);
 231                 n = num - n;
 232         }
 233         spin_lock_irqsave(&free_pages_lock, flags);
 234         for (i = 0; i < n; i++)
 235                 list_add(&page[i]->lru, &scsiback_free_pages);
 236         free_pages_num += n;
 237         spin_unlock_irqrestore(&free_pages_lock, flags);
 238 }
 239
 240 static int get_free_page(struct page **page)
 241 {
 242         unsigned long flags;
 243
 244         spin_lock_irqsave(&free_pages_lock, flags);
 245         if (list_empty(&scsiback_free_pages)) {
 246                 spin_unlock_irqrestore(&free_pages_lock, flags);
 247                 return alloc_xenballooned_pages(1, page, false);
 248         }
 249         page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
 250         list_del(&page[0]->lru);
 251         free_pages_num--;
 252         spin_unlock_irqrestore(&free_pages_lock, flags);
 253         return 0;
 254 }
 255
 256 static unsigned long vaddr_page(struct page *page)
 257 {
 258         unsigned long pfn = page_to_pfn(page);
 259
 260         return (unsigned long)pfn_to_kaddr(pfn);
 261 }
 262
 263 static unsigned long vaddr(struct vscsibk_pend *req, int seg)
 264 {
 265         return vaddr_page(req->pages[seg]);
 266 }
 267
 268 static void scsiback_print_status(char *sense_buffer, int errors,
 269                                         struct vscsibk_pend *pending_req)
 270 {
 271         struct scsiback_tpg *tpg = pending_req->v2p->tpg;
 272
 273         pr_err("xen-pvscsi[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n",
 274                tpg->tport->tport_name, pending_req->v2p->lun,
 275                pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
 276                host_byte(errors), driver_byte(errors));
 277
 278         if (CHECK_CONDITION & status_byte(errors))
 279                 __scsi_print_sense("xen-pvscsi", sense_buffer,
 280                                    SCSI_SENSE_BUFFERSIZE);
 281 }
 282
 283 static void scsiback_fast_flush_area(struct vscsibk_pend *req)
 284 {
 285         struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
 286         struct page *pages[VSCSI_GRANT_BATCH];
 287         unsigned int i, invcount = 0;
 288         grant_handle_t handle;
 289         int err;
 290
 291         kfree(req->sgl);
 292         req->sgl = NULL;
 293         req->n_sg = 0;
 294
 295         if (!req->n_grants)
 296                 return;
 297
 298         for (i = 0; i < req->n_grants; i++) {
 299                 handle = req->grant_handles[i];
 300                 if (handle == SCSIBACK_INVALID_HANDLE)
 301                         continue;
 302                 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
 303                                     GNTMAP_host_map, handle);
 304                 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
 305                 pages[invcount] = req->pages[i];
 306                 put_page(pages[invcount]);
 307                 invcount++;
 308                 if (invcount < VSCSI_GRANT_BATCH)
 309                         continue;
 310                 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
 311                 BUG_ON(err);
 312                 invcount = 0;
 313         }
 314
 315         if (invcount) {
 316                 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
 317                 BUG_ON(err);
 318         }
 319
 320         put_free_pages(req->pages, req->n_grants);
 321         req->n_grants = 0;
 322 }
 323
 324 static void scsiback_free_translation_entry(struct kref *kref)
 325 {
 326         struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
 327         struct scsiback_tpg *tpg = entry->tpg;
 328
 329         mutex_lock(&tpg->tv_tpg_mutex);
 330         tpg->tv_tpg_fe_count--;
 331         mutex_unlock(&tpg->tv_tpg_mutex);
 332
 333         kfree(entry);
 334 }
 335
 336 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
 337                         uint32_t resid, struct vscsibk_pend *pending_req)
 338 {
 339         struct vscsiif_response *ring_res;
 340         struct vscsibk_info *info = pending_req->info;
 341         int notify;
 342         struct scsi_sense_hdr sshdr;
 343         unsigned long flags;
 344         unsigned len;
 345
 346         spin_lock_irqsave(&info->ring_lock, flags);
 347
 348         ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
 349         info->ring.rsp_prod_pvt++;
 350
 351         ring_res->rslt   = result;
 352         ring_res->rqid   = pending_req->rqid;
 353
 354         if (sense_buffer != NULL &&
 355             scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
 356                                  &sshdr)) {
 357                 len = min_t(unsigned, 8 + sense_buffer[7],
 358                             VSCSIIF_SENSE_BUFFERSIZE);
 359                 memcpy(ring_res->sense_buffer, sense_buffer, len);
 360                 ring_res->sense_len = len;
 361         } else {
 362                 ring_res->sense_len = 0;
 363         }
 364
 365         ring_res->residual_len = resid;
 366
 367         RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
 368         spin_unlock_irqrestore(&info->ring_lock, flags);
 369
 370         if (notify)
 371                 notify_remote_via_irq(info->irq);
 372
 373         if (pending_req->v2p)
 374                 kref_put(&pending_req->v2p->kref,
 375                          scsiback_free_translation_entry);
 376 }
 377
 378 static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
 379 {
 380         struct vscsibk_info *info = pending_req->info;
 381         unsigned char *sense_buffer;
 382         unsigned int resid;
 383         int errors;
 384
 385         sense_buffer = pending_req->sense_buffer;
 386         resid        = pending_req->se_cmd.residual_count;
 387         errors       = pending_req->result;
 388
 389         if (errors && log_print_stat)
 390                 scsiback_print_status(sense_buffer, errors, pending_req);
 391
 392         scsiback_fast_flush_area(pending_req);
 393         scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
 394         scsiback_put(info);
 395 }
 396
 397 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
 398 {
 399         struct se_cmd *se_cmd = &pending_req->se_cmd;
 400         struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
 401         int rc;
 402
 403         memset(pending_req->sense_buffer, 0, VSCSIIF_SENSE_BUFFERSIZE);
 404
 405         memset(se_cmd, 0, sizeof(*se_cmd));
 406
 407         scsiback_get(pending_req->info);
 408         rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
 409                         pending_req->sense_buffer, pending_req->v2p->lun,
 410                         pending_req->data_len, 0,
 411                         pending_req->sc_data_direction, 0,
 412                         pending_req->sgl, pending_req->n_sg,
 413                         NULL, 0, NULL, 0);
 414         if (rc < 0) {
 415                 transport_send_check_condition_and_sense(se_cmd,
 416                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 417                 transport_generic_free_cmd(se_cmd, 0);
 418         }
 419 }
 420
 421 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
 422         struct page **pg, grant_handle_t *grant, int cnt)
 423 {
 424         int err, i;
 425
 426         if (!cnt)
 427                 return 0;
 428
 429         err = gnttab_map_refs(map, NULL, pg, cnt);
 430         BUG_ON(err);
 431         for (i = 0; i < cnt; i++) {
 432                 if (unlikely(map[i].status != GNTST_okay)) {
 433                         pr_err("xen-pvscsi: invalid buffer -- could not remap it\n");
 434                         map[i].handle = SCSIBACK_INVALID_HANDLE;
 435                         err = -ENOMEM;
 436                 } else {
 437                         get_page(pg[i]);
 438                 }
 439                 grant[i] = map[i].handle;
 440         }
 441         return err;
 442 }
 443
 444 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
 445                         struct scsiif_request_segment *seg, struct page **pg,
 446                         grant_handle_t *grant, int cnt, u32 flags)
 447 {
 448         int mapcount = 0, i, err = 0;
 449         struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
 450         struct vscsibk_info *info = pending_req->info;
 451
 452         for (i = 0; i < cnt; i++) {
 453                 if (get_free_page(pg + mapcount)) {
 454                         put_free_pages(pg, mapcount);
 455                         pr_err("xen-pvscsi: no grant page\n");
 456                         return -ENOMEM;
 457                 }
 458                 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
 459                                   flags, seg[i].gref, info->domid);
 460                 mapcount++;
 461                 if (mapcount < VSCSI_GRANT_BATCH)
 462                         continue;
 463                 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
 464                 pg += mapcount;
 465                 grant += mapcount;
 466                 pending_req->n_grants += mapcount;
 467                 if (err)
 468                         return err;
 469                 mapcount = 0;
 470         }
 471         err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
 472         pending_req->n_grants += mapcount;
 473         return err;
 474 }
 475
 476 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
 477                                         struct vscsibk_pend *pending_req)
 478 {
 479         u32 flags;
 480         int i, err, n_segs, i_seg = 0;
 481         struct page **pg;
 482         struct scsiif_request_segment *seg;
 483         unsigned long end_seg = 0;
 484         unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
 485         unsigned int nr_sgl = 0;
 486         struct scatterlist *sg;
 487         grant_handle_t *grant;
 488
 489         pending_req->n_sg = 0;
 490         pending_req->n_grants = 0;
 491         pending_req->data_len = 0;
 492
 493         nr_segments &= ~VSCSIIF_SG_GRANT;
 494         if (!nr_segments)
 495                 return 0;
 496
 497         if (nr_segments > VSCSIIF_SG_TABLESIZE) {
 498                 DPRINTK("xen-pvscsi: invalid parameter nr_seg = %d\n",
 499                         ring_req->nr_segments);
 500                 return -EINVAL;
 501         }
 502
 503         if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
 504                 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
 505                         pending_req->pages, pending_req->grant_handles,
 506                         nr_segments, GNTMAP_host_map | GNTMAP_readonly);
 507                 if (err)
 508                         return err;
 509                 nr_sgl = nr_segments;
 510                 nr_segments = 0;
 511                 for (i = 0; i < nr_sgl; i++) {
 512                         n_segs = ring_req->seg[i].length /
 513                                  sizeof(struct scsiif_request_segment);
 514                         if ((unsigned)ring_req->seg[i].offset +
 515                             (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
 516                             n_segs * sizeof(struct scsiif_request_segment) !=
 517                             ring_req->seg[i].length)
 518                                 return -EINVAL;
 519                         nr_segments += n_segs;
 520                 }
 521                 if (nr_segments > SG_ALL) {
 522                         DPRINTK("xen-pvscsi: invalid nr_seg = %d\n",
 523                                 nr_segments);
 524                         return -EINVAL;
 525                 }
 526         }
 527
 528         /* free of (sgl) in fast_flush_area()*/
 529         pending_req->sgl = kmalloc_array(nr_segments,
 530                                         sizeof(struct scatterlist), GFP_KERNEL);
 531         if (!pending_req->sgl)
 532                 return -ENOMEM;
 533
 534         sg_init_table(pending_req->sgl, nr_segments);
 535         pending_req->n_sg = nr_segments;
 536
 537         flags = GNTMAP_host_map;
 538         if (pending_req->sc_data_direction == DMA_TO_DEVICE)
 539                 flags |= GNTMAP_readonly;
 540
 541         pg = pending_req->pages + nr_sgl;
 542         grant = pending_req->grant_handles + nr_sgl;
 543         if (!nr_sgl) {
 544                 seg = ring_req->seg;
 545                 err = scsiback_gnttab_data_map_list(pending_req, seg,
 546                         pg, grant, nr_segments, flags);
 547                 if (err)
 548                         return err;
 549         } else {
 550                 for (i = 0; i < nr_sgl; i++) {
 551                         seg = (struct scsiif_request_segment *)(
 552                               vaddr(pending_req, i) + ring_req->seg[i].offset);
 553                         n_segs = ring_req->seg[i].length /
 554                                  sizeof(struct scsiif_request_segment);
 555                         err = scsiback_gnttab_data_map_list(pending_req, seg,
 556                                 pg, grant, n_segs, flags);
 557                         if (err)
 558                                 return err;
 559                         pg += n_segs;
 560                         grant += n_segs;
 561                 }
 562                 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
 563                 seg = (struct scsiif_request_segment *)end_seg;
 564                 end_seg += ring_req->seg[0].length;
 565                 pg = pending_req->pages + nr_sgl;
 566         }
 567
 568         for_each_sg(pending_req->sgl, sg, nr_segments, i) {
 569                 sg_set_page(sg, pg[i], seg->length, seg->offset);
 570                 pending_req->data_len += seg->length;
 571                 seg++;
 572                 if (nr_sgl && (unsigned long)seg >= end_seg) {
 573                         i_seg++;
 574                         end_seg = vaddr(pending_req, i_seg) +
 575                                   ring_req->seg[i_seg].offset;
 576                         seg = (struct scsiif_request_segment *)end_seg;
 577                         end_seg += ring_req->seg[i_seg].length;
 578                 }
 579                 if (sg->offset >= PAGE_SIZE ||
 580                     sg->length > PAGE_SIZE ||
 581                     sg->offset + sg->length > PAGE_SIZE)
 582                         return -EINVAL;
 583         }
 584
 585         return 0;
 586 }
 587
 588 static void scsiback_disconnect(struct vscsibk_info *info)
 589 {
 590         wait_event(info->waiting_to_free,
 591                 atomic_read(&info->nr_unreplied_reqs) == 0);
 592
 593         unbind_from_irqhandler(info->irq, info);
 594         info->irq = 0;
 595         xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
 596 }
 597
 598 static void scsiback_device_action(struct vscsibk_pend *pending_req,
 599         enum tcm_tmreq_table act, int tag)
 600 {
 601         int rc, err = FAILED;
 602         struct scsiback_tpg *tpg = pending_req->v2p->tpg;
 603         struct se_cmd *se_cmd = &pending_req->se_cmd;
 604         struct scsiback_tmr *tmr;
 605
 606         tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
 607         if (!tmr)
 608                 goto out;
 609
 610         init_waitqueue_head(&tmr->tmr_wait);
 611
 612         transport_init_se_cmd(se_cmd, tpg->se_tpg.se_tpg_tfo,
 613                 tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, MSG_SIMPLE_TAG,
 614                 &pending_req->sense_buffer[0]);
 615
 616         rc = core_tmr_alloc_req(se_cmd, tmr, act, GFP_KERNEL);
 617         if (rc < 0)
 618                 goto out;
 619
 620         se_cmd->se_tmr_req->ref_task_tag = tag;
 621
 622         if (transport_lookup_tmr_lun(se_cmd, pending_req->v2p->lun) < 0)
 623                 goto out;
 624
 625         transport_generic_handle_tmr(se_cmd);
 626         wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
 627
 628         err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
 629                 SUCCESS : FAILED;
 630
 631 out:
 632         if (tmr) {
 633                 transport_generic_free_cmd(&pending_req->se_cmd, 1);
 634                 kfree(tmr);
 635         }
 636
 637         scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
 638
 639         kmem_cache_free(scsiback_cachep, pending_req);
 640 }
 641
 642 /*
 643   Perform virtual to physical translation
 644 */
 645 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
 646                         struct ids_tuple *v)
 647 {
 648         struct v2p_entry *entry;
 649         struct list_head *head = &(info->v2p_entry_lists);
 650         unsigned long flags;
 651
 652         spin_lock_irqsave(&info->v2p_lock, flags);
 653         list_for_each_entry(entry, head, l) {
 654                 if ((entry->v.chn == v->chn) &&
 655                     (entry->v.tgt == v->tgt) &&
 656                     (entry->v.lun == v->lun)) {
 657                         kref_get(&entry->kref);
 658                         goto out;
 659                 }
 660         }
 661         entry = NULL;
 662
 663 out:
 664         spin_unlock_irqrestore(&info->v2p_lock, flags);
 665         return entry;
 666 }
 667
 668 static int prepare_pending_reqs(struct vscsibk_info *info,
 669                                 struct vscsiif_request *ring_req,
 670                                 struct vscsibk_pend *pending_req)
 671 {
 672         struct v2p_entry *v2p;
 673         struct ids_tuple vir;
 674
 675         pending_req->rqid       = ring_req->rqid;
 676         pending_req->info       = info;
 677
 678         vir.chn = ring_req->channel;
 679         vir.tgt = ring_req->id;
 680         vir.lun = ring_req->lun;
 681
 682         v2p = scsiback_do_translation(info, &vir);
 683         if (!v2p) {
 684                 pending_req->v2p = NULL;
 685                 DPRINTK("xen-pvscsi: doesn't exist.\n");
 686                 return -ENODEV;
 687         }
 688         pending_req->v2p = v2p;
 689
 690         /* request range check from frontend */
 691         pending_req->sc_data_direction = ring_req->sc_data_direction;
 692         if ((pending_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
 693                 (pending_req->sc_data_direction != DMA_TO_DEVICE) &&
 694                 (pending_req->sc_data_direction != DMA_FROM_DEVICE) &&
 695                 (pending_req->sc_data_direction != DMA_NONE)) {
 696                 DPRINTK("xen-pvscsi: invalid parameter data_dir = %d\n",
 697                         pending_req->sc_data_direction);
 698                 return -EINVAL;
 699         }
 700
 701         pending_req->cmd_len = ring_req->cmd_len;
 702         if (pending_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
 703                 DPRINTK("xen-pvscsi: invalid parameter cmd_len = %d\n",
 704                         pending_req->cmd_len);
 705                 return -EINVAL;
 706         }
 707         memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
 708
 709         return 0;
 710 }
 711
 712 static int scsiback_do_cmd_fn(struct vscsibk_info *info)
 713 {
 714         struct vscsiif_back_ring *ring = &info->ring;
 715         struct vscsiif_request *ring_req;
 716         struct vscsibk_pend *pending_req;
 717         RING_IDX rc, rp;
 718         int err, more_to_do;
 719         uint32_t result;
 720         uint8_t act;
 721
 722         rc = ring->req_cons;
 723         rp = ring->sring->req_prod;
 724         rmb();  /* guest system is accessing ring, too */
 725
 726         if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
 727                 rc = ring->rsp_prod_pvt;
 728                 pr_warn("xen-pvscsi: Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
 729                            info->domid, rp, rc, rp - rc);
 730                 info->ring_error = 1;
 731                 return 0;
 732         }
 733
 734         while ((rc != rp)) {
 735                 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
 736                         break;
 737                 pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL);
 738                 if (!pending_req)
 739                         return 1;
 740
 741                 ring_req = RING_GET_REQUEST(ring, rc);
 742                 ring->req_cons = ++rc;
 743
 744                 act = ring_req->act;
 745                 err = prepare_pending_reqs(info, ring_req, pending_req);
 746                 if (err) {
 747                         switch (err) {
 748                         case -ENODEV:
 749                                 result = DID_NO_CONNECT;
 750                                 break;
 751                         default:
 752                                 result = DRIVER_ERROR;
 753                                 break;
 754                         }
 755                         scsiback_do_resp_with_sense(NULL, result << 24, 0,
 756                                                     pending_req);
 757                         kmem_cache_free(scsiback_cachep, pending_req);
 758                         return 1;
 759                 }
 760
 761                 switch (act) {
 762                 case VSCSIIF_ACT_SCSI_CDB:
 763                         if (scsiback_gnttab_data_map(ring_req, pending_req)) {
 764                                 scsiback_fast_flush_area(pending_req);
 765                                 scsiback_do_resp_with_sense(NULL,
 766                                         DRIVER_ERROR << 24, 0, pending_req);
 767                                 kmem_cache_free(scsiback_cachep, pending_req);
 768                         } else {
 769                                 scsiback_cmd_exec(pending_req);
 770                         }
 771                         break;
 772                 case VSCSIIF_ACT_SCSI_ABORT:
 773                         scsiback_device_action(pending_req, TMR_ABORT_TASK,
 774                                 ring_req->ref_rqid);
 775                         break;
 776                 case VSCSIIF_ACT_SCSI_RESET:
 777                         scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
 778                         break;
 779                 default:
 780                         pr_err_ratelimited("xen-pvscsi: invalid request\n");
 781                         scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24,
 782                                                     0, pending_req);
 783                         kmem_cache_free(scsiback_cachep, pending_req);
 784                         break;
 785                 }
 786
 787                 /* Yield point for this unbounded loop. */
 788                 cond_resched();
 789         }
 790
 791         RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
 792         return more_to_do;
 793 }
 794
 795 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
 796 {
 797         struct vscsibk_info *info = dev_id;
 798
 799         if (info->ring_error)
 800                 return IRQ_HANDLED;
 801
 802         while (scsiback_do_cmd_fn(info))
 803                 cond_resched();
 804
 805         return IRQ_HANDLED;
 806 }
 807
 808 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
 809                         evtchn_port_t evtchn)
 810 {
 811         void *area;
 812         struct vscsiif_sring *sring;
 813         int err;
 814
 815         if (info->irq)
 816                 return -1;
 817
 818         err = xenbus_map_ring_valloc(info->dev, ring_ref, &area);
 819         if (err)
 820                 return err;
 821
 822         sring = (struct vscsiif_sring *)area;
 823         BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
 824
 825         err = bind_interdomain_evtchn_to_irq(info->domid, evtchn);
 826         if (err < 0)
 827                 goto unmap_page;
 828
 829         info->irq = err;
 830
 831         err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
 832                                    IRQF_ONESHOT, "vscsiif-backend", info);
 833         if (err)
 834                 goto free_irq;
 835
 836         return 0;
 837
 838 free_irq:
 839         unbind_from_irqhandler(info->irq, info);
 840         info->irq = 0;
 841 unmap_page:
 842         xenbus_unmap_ring_vfree(info->dev, area);
 843
 844         return err;
 845 }
 846
 847 static int scsiback_map(struct vscsibk_info *info)
 848 {
 849         struct xenbus_device *dev = info->dev;
 850         unsigned int ring_ref, evtchn;
 851         int err;
 852
 853         err = xenbus_gather(XBT_NIL, dev->otherend,
 854                         "ring-ref", "%u", &ring_ref,
 855                         "event-channel", "%u", &evtchn, NULL);
 856         if (err) {
 857                 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
 858                 return err;
 859         }
 860
 861         return scsiback_init_sring(info, ring_ref, evtchn);
 862 }
 863
 864 /*
 865   Add a new translation entry
 866 */
 867 static int scsiback_add_translation_entry(struct vscsibk_info *info,
 868                                           char *phy, struct ids_tuple *v)
 869 {
 870         int err = 0;
 871         struct v2p_entry *entry;
 872         struct v2p_entry *new;
 873         struct list_head *head = &(info->v2p_entry_lists);
 874         unsigned long flags;
 875         char *lunp;
 876         unsigned int lun;
 877         struct scsiback_tpg *tpg_entry, *tpg = NULL;
 878         char *error = "doesn't exist";
 879
 880         lunp = strrchr(phy, ':');
 881         if (!lunp) {
 882                 pr_err("xen-pvscsi: illegal format of physical device %s\n",
 883                         phy);
 884                 return -EINVAL;
 885         }
 886         *lunp = 0;
 887         lunp++;
 888         if (kstrtouint(lunp, 10, &lun) || lun >= TRANSPORT_MAX_LUNS_PER_TPG) {
 889                 pr_err("xen-pvscsi: lun number not valid: %s\n", lunp);
 890                 return -EINVAL;
 891         }
 892
 893         mutex_lock(&scsiback_mutex);
 894         list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
 895                 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
 896                     !strcmp(phy, tpg_entry->param_alias)) {
 897                         spin_lock(&tpg_entry->se_tpg.tpg_lun_lock);
 898                         if (tpg_entry->se_tpg.tpg_lun_list[lun]->lun_status ==
 899                             TRANSPORT_LUN_STATUS_ACTIVE) {
 900                                 if (!tpg_entry->tpg_nexus)
 901                                         error = "nexus undefined";
 902                                 else
 903                                         tpg = tpg_entry;
 904                         }
 905                         spin_unlock(&tpg_entry->se_tpg.tpg_lun_lock);
 906                         break;
 907                 }
 908         }
 909         if (tpg) {
 910                 mutex_lock(&tpg->tv_tpg_mutex);
 911                 tpg->tv_tpg_fe_count++;
 912                 mutex_unlock(&tpg->tv_tpg_mutex);
 913         }
 914         mutex_unlock(&scsiback_mutex);
 915
 916         if (!tpg) {
 917                 pr_err("xen-pvscsi: %s:%d %s\n", phy, lun, error);
 918                 return -ENODEV;
 919         }
 920
 921         new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
 922         if (new == NULL) {
 923                 err = -ENOMEM;
 924                 goto out_free;
 925         }
 926
 927         spin_lock_irqsave(&info->v2p_lock, flags);
 928
 929         /* Check double assignment to identical virtual ID */
 930         list_for_each_entry(entry, head, l) {
 931                 if ((entry->v.chn == v->chn) &&
 932                     (entry->v.tgt == v->tgt) &&
 933                     (entry->v.lun == v->lun)) {
 934                         pr_warn("xen-pvscsi: Virtual ID is already used. Assignment was not performed.\n");
 935                         err = -EEXIST;
 936                         goto out;
 937                 }
 938
 939         }
 940
 941         /* Create a new translation entry and add to the list */
 942         kref_init(&new->kref);
 943         new->v = *v;
 944         new->tpg = tpg;
 945         new->lun = lun;
 946         list_add_tail(&new->l, head);
 947
 948 out:
 949         spin_unlock_irqrestore(&info->v2p_lock, flags);
 950
 951 out_free:
 952         mutex_lock(&tpg->tv_tpg_mutex);
 953         tpg->tv_tpg_fe_count--;
 954         mutex_unlock(&tpg->tv_tpg_mutex);
 955
 956         if (err)
 957                 kfree(new);
 958
 959         return err;
 960 }
 961
 962 static void __scsiback_del_translation_entry(struct v2p_entry *entry)
 963 {
 964         list_del(&entry->l);
 965         kref_put(&entry->kref, scsiback_free_translation_entry);
 966 }
 967
 968 /*
 969   Delete the translation entry specfied
 970 */
 971 static int scsiback_del_translation_entry(struct vscsibk_info *info,
 972                                           struct ids_tuple *v)
 973 {
 974         struct v2p_entry *entry;
 975         struct list_head *head = &(info->v2p_entry_lists);
 976         unsigned long flags;
 977
 978         spin_lock_irqsave(&info->v2p_lock, flags);
 979         /* Find out the translation entry specified */
 980         list_for_each_entry(entry, head, l) {
 981                 if ((entry->v.chn == v->chn) &&
 982                     (entry->v.tgt == v->tgt) &&
 983                     (entry->v.lun == v->lun)) {
 984                         goto found;
 985                 }
 986         }
 987
 988         spin_unlock_irqrestore(&info->v2p_lock, flags);
 989         return 1;
 990
 991 found:
 992         /* Delete the translation entry specfied */
 993         __scsiback_del_translation_entry(entry);
 994
 995         spin_unlock_irqrestore(&info->v2p_lock, flags);
 996         return 0;
 997 }
 998
 999 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
1000                                 char *phy, struct ids_tuple *vir)
1001 {
1002         if (!scsiback_add_translation_entry(info, phy, vir)) {
1003                 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1004                                   "%d", XenbusStateInitialised)) {
1005                         pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1006                         scsiback_del_translation_entry(info, vir);
1007                 }
1008         } else {
1009                 xenbus_printf(XBT_NIL, info->dev->nodename, state,
1010                               "%d", XenbusStateClosed);
1011         }
1012 }
1013
1014 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1015                                 struct ids_tuple *vir)
1016 {
1017         if (!scsiback_del_translation_entry(info, vir)) {
1018                 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1019                                   "%d", XenbusStateClosed))
1020                         pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
1021         }
1022 }
1023
1024 #define VSCSIBACK_OP_ADD_OR_DEL_LUN     1
1025 #define VSCSIBACK_OP_UPDATEDEV_STATE    2
1026
1027 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1028                                      char *ent)
1029 {
1030         int err;
1031         struct ids_tuple vir;
1032         char *val;
1033         int device_state;
1034         char phy[VSCSI_NAMELEN];
1035         char str[64];
1036         char state[64];
1037         struct xenbus_device *dev = info->dev;
1038
1039         /* read status */
1040         snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1041         err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1042         if (XENBUS_EXIST_ERR(err))
1043                 return;
1044
1045         /* physical SCSI device */
1046         snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1047         val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1048         if (IS_ERR(val)) {
1049                 xenbus_printf(XBT_NIL, dev->nodename, state,
1050                               "%d", XenbusStateClosed);
1051                 return;
1052         }
1053         strlcpy(phy, val, VSCSI_NAMELEN);
1054         kfree(val);
1055
1056         /* virtual SCSI device */
1057         snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1058         err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1059                            &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1060         if (XENBUS_EXIST_ERR(err)) {
1061                 xenbus_printf(XBT_NIL, dev->nodename, state,
1062                               "%d", XenbusStateClosed);
1063                 return;
1064         }
1065
1066         switch (op) {
1067         case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1068                 if (device_state == XenbusStateInitialising)
1069                         scsiback_do_add_lun(info, state, phy, &vir);
1070                 if (device_state == XenbusStateClosing)
1071                         scsiback_do_del_lun(info, state, &vir);
1072                 break;
1073
1074         case VSCSIBACK_OP_UPDATEDEV_STATE:
1075                 if (device_state == XenbusStateInitialised) {
1076                         /* modify vscsi-devs/dev-x/state */
1077                         if (xenbus_printf(XBT_NIL, dev->nodename, state,
1078                                           "%d", XenbusStateConnected)) {
1079                                 pr_err("xen-pvscsi: xenbus_printf error %s\n",
1080                                        str);
1081                                 scsiback_del_translation_entry(info, &vir);
1082                                 xenbus_printf(XBT_NIL, dev->nodename, state,
1083                                               "%d", XenbusStateClosed);
1084                         }
1085                 }
1086                 break;
1087         /*When it is necessary, processing is added here.*/
1088         default:
1089                 break;
1090         }
1091 }
1092
1093 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1094 {
1095         int i;
1096         char **dir;
1097         unsigned int ndir = 0;
1098
1099         dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1100                                &ndir);
1101         if (IS_ERR(dir))
1102                 return;
1103
1104         for (i = 0; i < ndir; i++)
1105                 scsiback_do_1lun_hotplug(info, op, dir[i]);
1106
1107         kfree(dir);
1108 }
1109
1110 static void scsiback_frontend_changed(struct xenbus_device *dev,
1111                                         enum xenbus_state frontend_state)
1112 {
1113         struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1114
1115         switch (frontend_state) {
1116         case XenbusStateInitialising:
1117                 break;
1118
1119         case XenbusStateInitialised:
1120                 if (scsiback_map(info))
1121                         break;
1122
1123                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1124                 xenbus_switch_state(dev, XenbusStateConnected);
1125                 break;
1126
1127         case XenbusStateConnected:
1128                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1129
1130                 if (dev->state == XenbusStateConnected)
1131                         break;
1132
1133                 xenbus_switch_state(dev, XenbusStateConnected);
1134                 break;
1135
1136         case XenbusStateClosing:
1137                 if (info->irq)
1138                         scsiback_disconnect(info);
1139
1140                 xenbus_switch_state(dev, XenbusStateClosing);
1141                 break;
1142
1143         case XenbusStateClosed:
1144                 xenbus_switch_state(dev, XenbusStateClosed);
1145                 if (xenbus_dev_is_online(dev))
1146                         break;
1147                 /* fall through if not online */
1148         case XenbusStateUnknown:
1149                 device_unregister(&dev->dev);
1150                 break;
1151
1152         case XenbusStateReconfiguring:
1153                 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1154                 xenbus_switch_state(dev, XenbusStateReconfigured);
1155
1156                 break;
1157
1158         default:
1159                 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1160                                         frontend_state);
1161                 break;
1162         }
1163 }
1164
1165 /*
1166   Release the translation entry specfied
1167 */
1168 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1169 {
1170         struct v2p_entry *entry, *tmp;
1171         struct list_head *head = &(info->v2p_entry_lists);
1172         unsigned long flags;
1173
1174         spin_lock_irqsave(&info->v2p_lock, flags);
1175
1176         list_for_each_entry_safe(entry, tmp, head, l)
1177                 __scsiback_del_translation_entry(entry);
1178
1179         spin_unlock_irqrestore(&info->v2p_lock, flags);
1180 }
1181
1182 static int scsiback_remove(struct xenbus_device *dev)
1183 {
1184         struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1185
1186         if (info->irq)
1187                 scsiback_disconnect(info);
1188
1189         scsiback_release_translation_entry(info);
1190
1191         dev_set_drvdata(&dev->dev, NULL);
1192
1193         return 0;
1194 }
1195
1196 static int scsiback_probe(struct xenbus_device *dev,
1197                            const struct xenbus_device_id *id)
1198 {
1199         int err;
1200
1201         struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1202                                             GFP_KERNEL);
1203
1204         DPRINTK("%p %d\n", dev, dev->otherend_id);
1205
1206         if (!info) {
1207                 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1208                 return -ENOMEM;
1209         }
1210         info->dev = dev;
1211         dev_set_drvdata(&dev->dev, info);
1212
1213         info->domid = dev->otherend_id;
1214         spin_lock_init(&info->ring_lock);
1215         info->ring_error = 0;
1216         atomic_set(&info->nr_unreplied_reqs, 0);
1217         init_waitqueue_head(&info->waiting_to_free);
1218         info->dev = dev;
1219         info->irq = 0;
1220         INIT_LIST_HEAD(&info->v2p_entry_lists);
1221         spin_lock_init(&info->v2p_lock);
1222
1223         err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1224                             SG_ALL);
1225         if (err)
1226                 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1227
1228         err = xenbus_switch_state(dev, XenbusStateInitWait);
1229         if (err)
1230                 goto fail;
1231
1232         return 0;
1233
1234 fail:
1235         pr_warn("xen-pvscsi: %s failed\n", __func__);
1236         scsiback_remove(dev);
1237
1238         return err;
1239 }
1240
1241 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1242 {
1243         switch (tport->tport_proto_id) {
1244         case SCSI_PROTOCOL_SAS:
1245                 return "SAS";
1246         case SCSI_PROTOCOL_FCP:
1247                 return "FCP";
1248         case SCSI_PROTOCOL_ISCSI:
1249                 return "iSCSI";
1250         default:
1251                 break;
1252         }
1253
1254         return "Unknown";
1255 }
1256
1257 static u8 scsiback_get_fabric_proto_ident(struct se_portal_group *se_tpg)
1258 {
1259         struct scsiback_tpg *tpg = container_of(se_tpg,
1260                                 struct scsiback_tpg, se_tpg);
1261         struct scsiback_tport *tport = tpg->tport;
1262
1263         switch (tport->tport_proto_id) {
1264         case SCSI_PROTOCOL_SAS:
1265                 return sas_get_fabric_proto_ident(se_tpg);
1266         case SCSI_PROTOCOL_FCP:
1267                 return fc_get_fabric_proto_ident(se_tpg);
1268         case SCSI_PROTOCOL_ISCSI:
1269                 return iscsi_get_fabric_proto_ident(se_tpg);
1270         default:
1271                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1272                         tport->tport_proto_id);
1273                 break;
1274         }
1275
1276         return sas_get_fabric_proto_ident(se_tpg);
1277 }
1278
1279 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1280 {
1281         struct scsiback_tpg *tpg = container_of(se_tpg,
1282                                 struct scsiback_tpg, se_tpg);
1283         struct scsiback_tport *tport = tpg->tport;
1284
1285         return &tport->tport_name[0];
1286 }
1287
1288 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1289 {
1290         struct scsiback_tpg *tpg = container_of(se_tpg,
1291                                 struct scsiback_tpg, se_tpg);
1292         return tpg->tport_tpgt;
1293 }
1294
1295 static u32 scsiback_get_default_depth(struct se_portal_group *se_tpg)
1296 {
1297         return 1;
1298 }
1299
1300 static u32
1301 scsiback_get_pr_transport_id(struct se_portal_group *se_tpg,
1302                               struct se_node_acl *se_nacl,
1303                               struct t10_pr_registration *pr_reg,
1304                               int *format_code,
1305                               unsigned char *buf)
1306 {
1307         struct scsiback_tpg *tpg = container_of(se_tpg,
1308                                 struct scsiback_tpg, se_tpg);
1309         struct scsiback_tport *tport = tpg->tport;
1310
1311         switch (tport->tport_proto_id) {
1312         case SCSI_PROTOCOL_SAS:
1313                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1314                                         format_code, buf);
1315         case SCSI_PROTOCOL_FCP:
1316                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1317                                         format_code, buf);
1318         case SCSI_PROTOCOL_ISCSI:
1319                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1320                                         format_code, buf);
1321         default:
1322                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1323                         tport->tport_proto_id);
1324                 break;
1325         }
1326
1327         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
1328                         format_code, buf);
1329 }
1330
1331 static u32
1332 scsiback_get_pr_transport_id_len(struct se_portal_group *se_tpg,
1333                                   struct se_node_acl *se_nacl,
1334                                   struct t10_pr_registration *pr_reg,
1335                                   int *format_code)
1336 {
1337         struct scsiback_tpg *tpg = container_of(se_tpg,
1338                                 struct scsiback_tpg, se_tpg);
1339         struct scsiback_tport *tport = tpg->tport;
1340
1341         switch (tport->tport_proto_id) {
1342         case SCSI_PROTOCOL_SAS:
1343                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1344                                         format_code);
1345         case SCSI_PROTOCOL_FCP:
1346                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1347                                         format_code);
1348         case SCSI_PROTOCOL_ISCSI:
1349                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1350                                         format_code);
1351         default:
1352                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1353                         tport->tport_proto_id);
1354                 break;
1355         }
1356
1357         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
1358                         format_code);
1359 }
1360
1361 static char *
1362 scsiback_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
1363                                     const char *buf,
1364                                     u32 *out_tid_len,
1365                                     char **port_nexus_ptr)
1366 {
1367         struct scsiback_tpg *tpg = container_of(se_tpg,
1368                                 struct scsiback_tpg, se_tpg);
1369         struct scsiback_tport *tport = tpg->tport;
1370
1371         switch (tport->tport_proto_id) {
1372         case SCSI_PROTOCOL_SAS:
1373                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1374                                         port_nexus_ptr);
1375         case SCSI_PROTOCOL_FCP:
1376                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1377                                         port_nexus_ptr);
1378         case SCSI_PROTOCOL_ISCSI:
1379                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1380                                         port_nexus_ptr);
1381         default:
1382                 pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
1383                         tport->tport_proto_id);
1384                 break;
1385         }
1386
1387         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
1388                         port_nexus_ptr);
1389 }
1390
1391 static struct se_wwn *
1392 scsiback_make_tport(struct target_fabric_configfs *tf,
1393                      struct config_group *group,
1394                      const char *name)
1395 {
1396         struct scsiback_tport *tport;
1397         char *ptr;
1398         u64 wwpn = 0;
1399         int off = 0;
1400
1401         tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1402         if (!tport)
1403                 return ERR_PTR(-ENOMEM);
1404
1405         tport->tport_wwpn = wwpn;
1406         /*
1407          * Determine the emulated Protocol Identifier and Target Port Name
1408          * based on the incoming configfs directory name.
1409          */
1410         ptr = strstr(name, "naa.");
1411         if (ptr) {
1412                 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1413                 goto check_len;
1414         }
1415         ptr = strstr(name, "fc.");
1416         if (ptr) {
1417                 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1418                 off = 3; /* Skip over "fc." */
1419                 goto check_len;
1420         }
1421         ptr = strstr(name, "iqn.");
1422         if (ptr) {
1423                 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1424                 goto check_len;
1425         }
1426
1427         pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1428         kfree(tport);
1429         return ERR_PTR(-EINVAL);
1430
1431 check_len:
1432         if (strlen(name) >= VSCSI_NAMELEN) {
1433                 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1434                         scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1435                 kfree(tport);
1436                 return ERR_PTR(-EINVAL);
1437         }
1438         snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1439
1440         pr_debug("xen-pvscsi: Allocated emulated Target %s Address: %s\n",
1441                  scsiback_dump_proto_id(tport), name);
1442
1443         return &tport->tport_wwn;
1444 }
1445
1446 static void scsiback_drop_tport(struct se_wwn *wwn)
1447 {
1448         struct scsiback_tport *tport = container_of(wwn,
1449                                 struct scsiback_tport, tport_wwn);
1450
1451         pr_debug("xen-pvscsi: Deallocating emulated Target %s Address: %s\n",
1452                  scsiback_dump_proto_id(tport), tport->tport_name);
1453
1454         kfree(tport);
1455 }
1456
1457 static struct se_node_acl *
1458 scsiback_alloc_fabric_acl(struct se_portal_group *se_tpg)
1459 {
1460         return kzalloc(sizeof(struct se_node_acl), GFP_KERNEL);
1461 }
1462
1463 static void
1464 scsiback_release_fabric_acl(struct se_portal_group *se_tpg,
1465                              struct se_node_acl *se_nacl)
1466 {
1467         kfree(se_nacl);
1468 }
1469
1470 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1471 {
1472         return 1;
1473 }
1474
1475 static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1476 {
1477         /*
1478          * Do not release struct se_cmd's containing a valid TMR
1479          * pointer.  These will be released directly in scsiback_device_action()
1480          * with transport_generic_free_cmd().
1481          */
1482         if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1483                 return 0;
1484
1485         transport_generic_free_cmd(se_cmd, 0);
1486         return 1;
1487 }
1488
1489 static void scsiback_release_cmd(struct se_cmd *se_cmd)
1490 {
1491         struct vscsibk_pend *pending_req = container_of(se_cmd,
1492                                 struct vscsibk_pend, se_cmd);
1493
1494         kmem_cache_free(scsiback_cachep, pending_req);
1495 }
1496
1497 static int scsiback_shutdown_session(struct se_session *se_sess)
1498 {
1499         return 0;
1500 }
1501
1502 static void scsiback_close_session(struct se_session *se_sess)
1503 {
1504 }
1505
1506 static u32 scsiback_sess_get_index(struct se_session *se_sess)
1507 {
1508         return 0;
1509 }
1510
1511 static int scsiback_write_pending(struct se_cmd *se_cmd)
1512 {
1513         /* Go ahead and process the write immediately */
1514         target_execute_cmd(se_cmd);
1515
1516         return 0;
1517 }
1518
1519 static int scsiback_write_pending_status(struct se_cmd *se_cmd)
1520 {
1521         return 0;
1522 }
1523
1524 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1525 {
1526 }
1527
1528 static u32 scsiback_get_task_tag(struct se_cmd *se_cmd)
1529 {
1530         struct vscsibk_pend *pending_req = container_of(se_cmd,
1531                                 struct vscsibk_pend, se_cmd);
1532
1533         return pending_req->rqid;
1534 }
1535
1536 static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1537 {
1538         return 0;
1539 }
1540
1541 static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1542 {
1543         struct vscsibk_pend *pending_req = container_of(se_cmd,
1544                                 struct vscsibk_pend, se_cmd);
1545
1546         pending_req->result = SAM_STAT_GOOD;
1547         scsiback_cmd_done(pending_req);
1548         return 0;
1549 }
1550
1551 static int scsiback_queue_status(struct se_cmd *se_cmd)
1552 {
1553         struct vscsibk_pend *pending_req = container_of(se_cmd,
1554                                 struct vscsibk_pend, se_cmd);
1555
1556         if (se_cmd->sense_buffer &&
1557             ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1558              (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1559                 pending_req->result = (DRIVER_SENSE << 24) |
1560                                       SAM_STAT_CHECK_CONDITION;
1561         else
1562                 pending_req->result = se_cmd->scsi_status;
1563
1564         scsiback_cmd_done(pending_req);
1565         return 0;
1566 }
1567
1568 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1569 {
1570         struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
1571         struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr;
1572
1573         atomic_set(&tmr->tmr_complete, 1);
1574         wake_up(&tmr->tmr_wait);
1575 }
1576
1577 static void scsiback_aborted_task(struct se_cmd *se_cmd)
1578 {
1579 }
1580
1581 static ssize_t scsiback_tpg_param_show_alias(struct se_portal_group *se_tpg,
1582                                              char *page)
1583 {
1584         struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1585                                                 se_tpg);
1586         ssize_t rb;
1587
1588         mutex_lock(&tpg->tv_tpg_mutex);
1589         rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1590         mutex_unlock(&tpg->tv_tpg_mutex);
1591
1592         return rb;
1593 }
1594
1595 static ssize_t scsiback_tpg_param_store_alias(struct se_portal_group *se_tpg,
1596                                               const char *page, size_t count)
1597 {
1598         struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1599                                                 se_tpg);
1600         int len;
1601
1602         if (strlen(page) >= VSCSI_NAMELEN) {
1603                 pr_err("param alias: %s, exceeds max: %d\n", page,
1604                         VSCSI_NAMELEN);
1605                 return -EINVAL;
1606         }
1607
1608         mutex_lock(&tpg->tv_tpg_mutex);
1609         len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1610         if (tpg->param_alias[len - 1] == '\n')
1611                 tpg->param_alias[len - 1] = '\0';
1612         mutex_unlock(&tpg->tv_tpg_mutex);
1613
1614         return count;
1615 }
1616
1617 TF_TPG_PARAM_ATTR(scsiback, alias, S_IRUGO | S_IWUSR);
1618
1619 static struct configfs_attribute *scsiback_param_attrs[] = {
1620         &scsiback_tpg_param_alias.attr,
1621         NULL,
1622 };
1623
1624 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1625                                 const char *name)
1626 {
1627         struct se_portal_group *se_tpg;
1628         struct se_session *se_sess;
1629         struct scsiback_nexus *tv_nexus;
1630
1631         mutex_lock(&tpg->tv_tpg_mutex);
1632         if (tpg->tpg_nexus) {
1633                 mutex_unlock(&tpg->tv_tpg_mutex);
1634                 pr_debug("tpg->tpg_nexus already exists\n");
1635                 return -EEXIST;
1636         }
1637         se_tpg = &tpg->se_tpg;
1638
1639         tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1640         if (!tv_nexus) {
1641                 mutex_unlock(&tpg->tv_tpg_mutex);
1642                 return -ENOMEM;
1643         }
1644         /*
1645          *  Initialize the struct se_session pointer
1646          */
1647         tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_NORMAL);
1648         if (IS_ERR(tv_nexus->tvn_se_sess)) {
1649                 mutex_unlock(&tpg->tv_tpg_mutex);
1650                 kfree(tv_nexus);
1651                 return -ENOMEM;
1652         }
1653         se_sess = tv_nexus->tvn_se_sess;
1654         /*
1655          * Since we are running in 'demo mode' this call with generate a
1656          * struct se_node_acl for the scsiback struct se_portal_group with
1657          * the SCSI Initiator port name of the passed configfs group 'name'.
1658          */
1659         tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1660                                 se_tpg, (unsigned char *)name);
1661         if (!tv_nexus->tvn_se_sess->se_node_acl) {
1662                 mutex_unlock(&tpg->tv_tpg_mutex);
1663                 pr_debug("core_tpg_check_initiator_node_acl() failed for %s\n",
1664                          name);
1665                 goto out;
1666         }
1667         /*
1668          * Now register the TCM pvscsi virtual I_T Nexus as active with the
1669          * call to __transport_register_session()
1670          */
1671         __transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
1672                         tv_nexus->tvn_se_sess, tv_nexus);
1673         tpg->tpg_nexus = tv_nexus;
1674
1675         mutex_unlock(&tpg->tv_tpg_mutex);
1676         return 0;
1677
1678 out:
1679         transport_free_session(se_sess);
1680         kfree(tv_nexus);
1681         return -ENOMEM;
1682 }
1683
1684 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1685 {
1686         struct se_session *se_sess;
1687         struct scsiback_nexus *tv_nexus;
1688
1689         mutex_lock(&tpg->tv_tpg_mutex);
1690         tv_nexus = tpg->tpg_nexus;
1691         if (!tv_nexus) {
1692                 mutex_unlock(&tpg->tv_tpg_mutex);
1693                 return -ENODEV;
1694         }
1695
1696         se_sess = tv_nexus->tvn_se_sess;
1697         if (!se_sess) {
1698                 mutex_unlock(&tpg->tv_tpg_mutex);
1699                 return -ENODEV;
1700         }
1701
1702         if (tpg->tv_tpg_port_count != 0) {
1703                 mutex_unlock(&tpg->tv_tpg_mutex);
1704                 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1705                         tpg->tv_tpg_port_count);
1706                 return -EBUSY;
1707         }
1708
1709         if (tpg->tv_tpg_fe_count != 0) {
1710                 mutex_unlock(&tpg->tv_tpg_mutex);
1711                 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1712                         tpg->tv_tpg_fe_count);
1713                 return -EBUSY;
1714         }
1715
1716         pr_debug("xen-pvscsi: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1717                 scsiback_dump_proto_id(tpg->tport),
1718                 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1719
1720         /*
1721          * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1722          */
1723         transport_deregister_session(tv_nexus->tvn_se_sess);
1724         tpg->tpg_nexus = NULL;
1725         mutex_unlock(&tpg->tv_tpg_mutex);
1726
1727         kfree(tv_nexus);
1728         return 0;
1729 }
1730
1731 static ssize_t scsiback_tpg_show_nexus(struct se_portal_group *se_tpg,
1732                                         char *page)
1733 {
1734         struct scsiback_tpg *tpg = container_of(se_tpg,
1735                                 struct scsiback_tpg, se_tpg);
1736         struct scsiback_nexus *tv_nexus;
1737         ssize_t ret;
1738
1739         mutex_lock(&tpg->tv_tpg_mutex);
1740         tv_nexus = tpg->tpg_nexus;
1741         if (!tv_nexus) {
1742                 mutex_unlock(&tpg->tv_tpg_mutex);
1743                 return -ENODEV;
1744         }
1745         ret = snprintf(page, PAGE_SIZE, "%s\n",
1746                         tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1747         mutex_unlock(&tpg->tv_tpg_mutex);
1748
1749         return ret;
1750 }
1751
1752 static ssize_t scsiback_tpg_store_nexus(struct se_portal_group *se_tpg,
1753                                          const char *page,
1754                                          size_t count)
1755 {
1756         struct scsiback_tpg *tpg = container_of(se_tpg,
1757                                 struct scsiback_tpg, se_tpg);
1758         struct scsiback_tport *tport_wwn = tpg->tport;
1759         unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1760         int ret;
1761         /*
1762          * Shutdown the active I_T nexus if 'NULL' is passed..
1763          */
1764         if (!strncmp(page, "NULL", 4)) {
1765                 ret = scsiback_drop_nexus(tpg);
1766                 return (!ret) ? count : ret;
1767         }
1768         /*
1769          * Otherwise make sure the passed virtual Initiator port WWN matches
1770          * the fabric protocol_id set in scsiback_make_tport(), and call
1771          * scsiback_make_nexus().
1772          */
1773         if (strlen(page) >= VSCSI_NAMELEN) {
1774                 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1775                         page, VSCSI_NAMELEN);
1776                 return -EINVAL;
1777         }
1778         snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1779
1780         ptr = strstr(i_port, "naa.");
1781         if (ptr) {
1782                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1783                         pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1784                                 i_port, scsiback_dump_proto_id(tport_wwn));
1785                         return -EINVAL;
1786                 }
1787                 port_ptr = &i_port[0];
1788                 goto check_newline;
1789         }
1790         ptr = strstr(i_port, "fc.");
1791         if (ptr) {
1792                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1793                         pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1794                                 i_port, scsiback_dump_proto_id(tport_wwn));
1795                         return -EINVAL;
1796                 }
1797                 port_ptr = &i_port[3]; /* Skip over "fc." */
1798                 goto check_newline;
1799         }
1800         ptr = strstr(i_port, "iqn.");
1801         if (ptr) {
1802                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1803                         pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1804                                 i_port, scsiback_dump_proto_id(tport_wwn));
1805                         return -EINVAL;
1806                 }
1807                 port_ptr = &i_port[0];
1808                 goto check_newline;
1809         }
1810         pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1811                 i_port);
1812         return -EINVAL;
1813         /*
1814          * Clear any trailing newline for the NAA WWN
1815          */
1816 check_newline:
1817         if (i_port[strlen(i_port) - 1] == '\n')
1818                 i_port[strlen(i_port) - 1] = '\0';
1819
1820         ret = scsiback_make_nexus(tpg, port_ptr);
1821         if (ret < 0)
1822                 return ret;
1823
1824         return count;
1825 }
1826
1827 TF_TPG_BASE_ATTR(scsiback, nexus, S_IRUGO | S_IWUSR);
1828
1829 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1830         &scsiback_tpg_nexus.attr,
1831         NULL,
1832 };
1833
1834 static ssize_t
1835 scsiback_wwn_show_attr_version(struct target_fabric_configfs *tf,
1836                                 char *page)
1837 {
1838         return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1839                 UTS_RELEASE"\n",
1840                 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1841 }
1842
1843 TF_WWN_ATTR_RO(scsiback, version);
1844
1845 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1846         &scsiback_wwn_version.attr,
1847         NULL,
1848 };
1849
1850 static char *scsiback_get_fabric_name(void)
1851 {
1852         return "xen-pvscsi";
1853 }
1854
1855 static int scsiback_port_link(struct se_portal_group *se_tpg,
1856                                struct se_lun *lun)
1857 {
1858         struct scsiback_tpg *tpg = container_of(se_tpg,
1859                                 struct scsiback_tpg, se_tpg);
1860
1861         mutex_lock(&tpg->tv_tpg_mutex);
1862         tpg->tv_tpg_port_count++;
1863         mutex_unlock(&tpg->tv_tpg_mutex);
1864
1865         return 0;
1866 }
1867
1868 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1869                                   struct se_lun *lun)
1870 {
1871         struct scsiback_tpg *tpg = container_of(se_tpg,
1872                                 struct scsiback_tpg, se_tpg);
1873
1874         mutex_lock(&tpg->tv_tpg_mutex);
1875         tpg->tv_tpg_port_count--;
1876         mutex_unlock(&tpg->tv_tpg_mutex);
1877 }
1878
1879 static struct se_portal_group *
1880 scsiback_make_tpg(struct se_wwn *wwn,
1881                    struct config_group *group,
1882                    const char *name)
1883 {
1884         struct scsiback_tport *tport = container_of(wwn,
1885                         struct scsiback_tport, tport_wwn);
1886
1887         struct scsiback_tpg *tpg;
1888         u16 tpgt;
1889         int ret;
1890
1891         if (strstr(name, "tpgt_") != name)
1892                 return ERR_PTR(-EINVAL);
1893         ret = kstrtou16(name + 5, 10, &tpgt);
1894         if (ret)
1895                 return ERR_PTR(ret);
1896
1897         tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1898         if (!tpg)
1899                 return ERR_PTR(-ENOMEM);
1900
1901         mutex_init(&tpg->tv_tpg_mutex);
1902         INIT_LIST_HEAD(&tpg->tv_tpg_list);
1903         INIT_LIST_HEAD(&tpg->info_list);
1904         tpg->tport = tport;
1905         tpg->tport_tpgt = tpgt;
1906
1907         ret = core_tpg_register(&scsiback_fabric_configfs->tf_ops, wwn,
1908                                 &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
1909         if (ret < 0) {
1910                 kfree(tpg);
1911                 return NULL;
1912         }
1913         mutex_lock(&scsiback_mutex);
1914         list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1915         mutex_unlock(&scsiback_mutex);
1916
1917         return &tpg->se_tpg;
1918 }
1919
1920 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1921 {
1922         struct scsiback_tpg *tpg = container_of(se_tpg,
1923                                 struct scsiback_tpg, se_tpg);
1924
1925         mutex_lock(&scsiback_mutex);
1926         list_del(&tpg->tv_tpg_list);
1927         mutex_unlock(&scsiback_mutex);
1928         /*
1929          * Release the virtual I_T Nexus for this xen-pvscsi TPG
1930          */
1931         scsiback_drop_nexus(tpg);
1932         /*
1933          * Deregister the se_tpg from TCM..
1934          */
1935         core_tpg_deregister(se_tpg);
1936         kfree(tpg);
1937 }
1938
1939 static int scsiback_check_true(struct se_portal_group *se_tpg)
1940 {
1941         return 1;
1942 }
1943
1944 static int scsiback_check_false(struct se_portal_group *se_tpg)
1945 {
1946         return 0;
1947 }
1948
1949 static struct target_core_fabric_ops scsiback_ops = {
1950         .get_fabric_name                = scsiback_get_fabric_name,
1951         .get_fabric_proto_ident         = scsiback_get_fabric_proto_ident,
1952         .tpg_get_wwn                    = scsiback_get_fabric_wwn,
1953         .tpg_get_tag                    = scsiback_get_tag,
1954         .tpg_get_default_depth          = scsiback_get_default_depth,
1955         .tpg_get_pr_transport_id        = scsiback_get_pr_transport_id,
1956         .tpg_get_pr_transport_id_len    = scsiback_get_pr_transport_id_len,
1957         .tpg_parse_pr_out_transport_id  = scsiback_parse_pr_out_transport_id,
1958         .tpg_check_demo_mode            = scsiback_check_true,
1959         .tpg_check_demo_mode_cache      = scsiback_check_true,
1960         .tpg_check_demo_mode_write_protect = scsiback_check_false,
1961         .tpg_check_prod_mode_write_protect = scsiback_check_false,
1962         .tpg_alloc_fabric_acl           = scsiback_alloc_fabric_acl,
1963         .tpg_release_fabric_acl         = scsiback_release_fabric_acl,
1964         .tpg_get_inst_index             = scsiback_tpg_get_inst_index,
1965         .check_stop_free                = scsiback_check_stop_free,
1966         .release_cmd                    = scsiback_release_cmd,
1967         .put_session                    = NULL,
1968         .shutdown_session               = scsiback_shutdown_session,
1969         .close_session                  = scsiback_close_session,
1970         .sess_get_index                 = scsiback_sess_get_index,
1971         .sess_get_initiator_sid         = NULL,
1972         .write_pending                  = scsiback_write_pending,
1973         .write_pending_status           = scsiback_write_pending_status,
1974         .set_default_node_attributes    = scsiback_set_default_node_attrs,
1975         .get_task_tag                   = scsiback_get_task_tag,
1976         .get_cmd_state                  = scsiback_get_cmd_state,
1977         .queue_data_in                  = scsiback_queue_data_in,
1978         .queue_status                   = scsiback_queue_status,
1979         .queue_tm_rsp                   = scsiback_queue_tm_rsp,
1980         .aborted_task                   = scsiback_aborted_task,
1981         /*
1982          * Setup callers for generic logic in target_core_fabric_configfs.c
1983          */
1984         .fabric_make_wwn                = scsiback_make_tport,
1985         .fabric_drop_wwn                = scsiback_drop_tport,
1986         .fabric_make_tpg                = scsiback_make_tpg,
1987         .fabric_drop_tpg                = scsiback_drop_tpg,
1988         .fabric_post_link               = scsiback_port_link,
1989         .fabric_pre_unlink              = scsiback_port_unlink,
1990         .fabric_make_np                 = NULL,
1991         .fabric_drop_np                 = NULL,
1992 #if 0
1993         .fabric_make_nodeacl            = scsiback_make_nodeacl,
1994         .fabric_drop_nodeacl            = scsiback_drop_nodeacl,
1995 #endif
1996 };
1997
1998 static int scsiback_register_configfs(void)
1999 {
2000         struct target_fabric_configfs *fabric;
2001         int ret;
2002
2003         pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
2004                  VSCSI_VERSION, utsname()->sysname, utsname()->machine);
2005         /*
2006          * Register the top level struct config_item_type with TCM core
2007          */
2008         fabric = target_fabric_configfs_init(THIS_MODULE, "xen-pvscsi");
2009         if (IS_ERR(fabric))
2010                 return PTR_ERR(fabric);
2011
2012         /*
2013          * Setup fabric->tf_ops from our local scsiback_ops
2014          */
2015         fabric->tf_ops = scsiback_ops;
2016         /*
2017          * Setup default attribute lists for various fabric->tf_cit_tmpl
2018          */
2019         fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = scsiback_wwn_attrs;
2020         fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = scsiback_tpg_attrs;
2021         fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
2022         fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = scsiback_param_attrs;
2023         fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
2024         fabric->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
2025         fabric->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
2026         fabric->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
2027         fabric->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
2028         /*
2029          * Register the fabric for use within TCM
2030          */
2031         ret = target_fabric_configfs_register(fabric);
2032         if (ret < 0) {
2033                 target_fabric_configfs_free(fabric);
2034                 return ret;
2035         }
2036         /*
2037          * Setup our local pointer to *fabric
2038          */
2039         scsiback_fabric_configfs = fabric;
2040         pr_debug("xen-pvscsi: Set fabric -> scsiback_fabric_configfs\n");
2041         return 0;
2042 };
2043
2044 static void scsiback_deregister_configfs(void)
2045 {
2046         if (!scsiback_fabric_configfs)
2047                 return;
2048
2049         target_fabric_configfs_deregister(scsiback_fabric_configfs);
2050         scsiback_fabric_configfs = NULL;
2051         pr_debug("xen-pvscsi: Cleared scsiback_fabric_configfs\n");
2052 };
2053
2054 static const struct xenbus_device_id scsiback_ids[] = {
2055         { "vscsi" },
2056         { "" }
2057 };
2058
2059 static struct xenbus_driver scsiback_driver = {
2060         .ids                    = scsiback_ids,
2061         .probe                  = scsiback_probe,
2062         .remove                 = scsiback_remove,
2063         .otherend_changed       = scsiback_frontend_changed
2064 };
2065
2066 static void scsiback_init_pend(void *p)
2067 {
2068         struct vscsibk_pend *pend = p;
2069         int i;
2070
2071         memset(pend, 0, sizeof(*pend));
2072         for (i = 0; i < VSCSI_MAX_GRANTS; i++)
2073                 pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
2074 }
2075
2076 static int __init scsiback_init(void)
2077 {
2078         int ret;
2079
2080         if (!xen_domain())
2081                 return -ENODEV;
2082
2083         scsiback_cachep = kmem_cache_create("vscsiif_cache",
2084                 sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
2085         if (!scsiback_cachep)
2086                 return -ENOMEM;
2087
2088         ret = xenbus_register_backend(&scsiback_driver);
2089         if (ret)
2090                 goto out_cache_destroy;
2091
2092         ret = scsiback_register_configfs();
2093         if (ret)
2094                 goto out_unregister_xenbus;
2095
2096         return 0;
2097
2098 out_unregister_xenbus:
2099         xenbus_unregister_driver(&scsiback_driver);
2100 out_cache_destroy:
2101         kmem_cache_destroy(scsiback_cachep);
2102         pr_err("xen-pvscsi: %s: error %d\n", __func__, ret);
2103         return ret;
2104 }
2105
2106 static void __exit scsiback_exit(void)
2107 {
2108         struct page *page;
2109
2110         while (free_pages_num) {
2111                 if (get_free_page(&page))
2112                         BUG();
2113                 free_xenballooned_pages(1, &page);
2114         }
2115         scsiback_deregister_configfs();
2116         xenbus_unregister_driver(&scsiback_driver);
2117         kmem_cache_destroy(scsiback_cachep);
2118 }
2119
2120 module_init(scsiback_init);
2121 module_exit(scsiback_exit);
2122
2123 MODULE_DESCRIPTION("Xen SCSI backend driver");
2124 MODULE_LICENSE("Dual BSD/GPL");
2125 MODULE_ALIAS("xen-backend:vscsi");
2126 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");